ADum mayilAi uruveDuttu anRu iRaivan tiruttAL
nADi arccitta nAyakiyAi nin nAmangaLaip
pADi urugip parvashamAgum appAngu aruLvAi
kADenavE pozhil shUzh mayilApurik kaRpagamE
Wednesday, October 4, 2017
Sunday, September 10, 2017
Memoirs of hunger
Memoirs of hunger: Bengal famine and thakuma's kitchen
The Bengal famine reached its pinnacle in 1943. The estimated number of
deaths was about five million. No wonder thakuma was obsessed with
reducing wastage.
Aditi Sen
We ate flowers, especially, marigold fritters. Spices were never used
for flavouring. We ate the cinnamon bark, chewed up cloves and
cardamoms; it was brutal. In my grandmother's farmhouse, not a morsel of
food was ever wasted. There were dishes made of veggie skins, pumpkin
seeds and cauliflower stalks. In a nutshell, we ate almost everything.
After a storm, we had to eat every fruit that fell from the tree, and if
a bat had nibbled on one, you just chopped that part off and ate the
rest.
Our village was a few hours away from Kolkata in 24 Parganas. My
grandfather had decided to buy the land next to a village graveyard to
ensure our isolation from the rest of humanity. My grandfather passed
away before I was born, and my grandmother (thakuma) looked after the
farm all by herself. She was completely self sufficient; owned rice
fields, grew veggies and fruits, had cows, chickens and a little fish
pond. Yet she would ask us to collect wild vegetables (dumur, dhundhul,
I don't know their English names) from the graveyard land. My cousin
became an expert in identifying greens; her job was collecting all kinds
of shaak (greens) that would be cooked up in a mess and served to us.
It mattered because my thakuma was a terrible cook. Thakuma hardly used
oil; we had an inside joke that she used homeopathy vials as oil cans.
The only flavour it had was of lemon, because we had plenty of lemon
trees. She reused tea leaves, diluted the milk, and made watery thin
curries. Her egg curry was made from scrambled eggs accompanied by
plenty of potatoes, and she would thicken it with some starch, so it was
heavy. One egg was enough to feed four.
Her rice pudding was used as a threat; if we didn't do our homework, we
would be fed her rice pudding. Her bad cooking never took away our love
for the farmhouse and her. Plus, the fresh fruits always made up for all
the bad cooking. In retrospect, it must have done wonders to my health.
I almost never fell sick. Later, when she was in her 70s, she decided to
live a little. That's when we discovered that inside this terrible cook,
lived a mediocre cook, who made very good egg kachoris.
Only recently, more than a year after her death, did I understand why
she was so fixated with saving food. It came to me after I attended a
talk on hunger museums in Russia, where they preserved memories of major
famines. The talk included recipes of bread made with grass and
clay—ways to use ingredients one wouldn't normally eat. I realized that
thakuma had survived the notorious Bengal famine that started in 1941
and lasted until 1946. There was no actual famine. Churchill was
instrumental in actively implementing it. When Japan entered the war in
1941, Calcutta became very important to the Allies. With the fall of
Burma in 1942, Calcutta became the easterly Allied front against the
Japanese. The colonial administration had to defend Calcutta at all
costs, and cut the Japanese access to any resources—especially food.
Surplus production from all districts of Bengal was directed to
Calcutta. The famine reached its pinnacle in 1943. The estimated number
of deaths was about five million, mostly from rural Bengal.
No wonder thakuma was obsessed with reducing wastage. She lived in rural
Bengal, and her life must have revolved around food shortage, even
though she never really talked about it. She told us stories about
ghosts who stole leftover food from plates, or ghosts who raided the
larder. There were endless tales of offending the goddess Annapurna, who
punished little girls who didn't eat everything that was on their
plates. We were always afraid that Annapurna or some ghost would find
out that we had secretly thrown away some food and she would punish us.
We were made to associate wasting food with immorality.
It took me very long to understand how my thakuma's fixation had also
shaped my own disposition. Wasting food bothers me much more than I am
willing to acknowledge. I remember being extremely agitated while
watching an American show where a teenage girl threw away a whole tray
of cupcakes because they were delicious, and eating them would make her
fat. I found myself yelling at the screen, "Freeze them, give them away.
Don't do it."
We now live in a culture where wastage is normal. It is very difficult
to discuss food wastage without sounding sanctimonious or preachy. The
adage, "eat up your veggies because children in Africa are going
hungry", doesn't work. We have taken our privileges for granted, and
hunger is often a choice for many. In these times of excess, famine is
unimaginable. All that lingers on is a lonely, dying memory of being
hungry long ago. Very, very hungry.
Aditi Sen is a historian based in Queen's University, Canada.
The Bengal famine reached its pinnacle in 1943. The estimated number of
deaths was about five million. No wonder thakuma was obsessed with
reducing wastage.
Aditi Sen
We ate flowers, especially, marigold fritters. Spices were never used
for flavouring. We ate the cinnamon bark, chewed up cloves and
cardamoms; it was brutal. In my grandmother's farmhouse, not a morsel of
food was ever wasted. There were dishes made of veggie skins, pumpkin
seeds and cauliflower stalks. In a nutshell, we ate almost everything.
After a storm, we had to eat every fruit that fell from the tree, and if
a bat had nibbled on one, you just chopped that part off and ate the
rest.
Our village was a few hours away from Kolkata in 24 Parganas. My
grandfather had decided to buy the land next to a village graveyard to
ensure our isolation from the rest of humanity. My grandfather passed
away before I was born, and my grandmother (thakuma) looked after the
farm all by herself. She was completely self sufficient; owned rice
fields, grew veggies and fruits, had cows, chickens and a little fish
pond. Yet she would ask us to collect wild vegetables (dumur, dhundhul,
I don't know their English names) from the graveyard land. My cousin
became an expert in identifying greens; her job was collecting all kinds
of shaak (greens) that would be cooked up in a mess and served to us.
It mattered because my thakuma was a terrible cook. Thakuma hardly used
oil; we had an inside joke that she used homeopathy vials as oil cans.
The only flavour it had was of lemon, because we had plenty of lemon
trees. She reused tea leaves, diluted the milk, and made watery thin
curries. Her egg curry was made from scrambled eggs accompanied by
plenty of potatoes, and she would thicken it with some starch, so it was
heavy. One egg was enough to feed four.
Her rice pudding was used as a threat; if we didn't do our homework, we
would be fed her rice pudding. Her bad cooking never took away our love
for the farmhouse and her. Plus, the fresh fruits always made up for all
the bad cooking. In retrospect, it must have done wonders to my health.
I almost never fell sick. Later, when she was in her 70s, she decided to
live a little. That's when we discovered that inside this terrible cook,
lived a mediocre cook, who made very good egg kachoris.
Only recently, more than a year after her death, did I understand why
she was so fixated with saving food. It came to me after I attended a
talk on hunger museums in Russia, where they preserved memories of major
famines. The talk included recipes of bread made with grass and
clay—ways to use ingredients one wouldn't normally eat. I realized that
thakuma had survived the notorious Bengal famine that started in 1941
and lasted until 1946. There was no actual famine. Churchill was
instrumental in actively implementing it. When Japan entered the war in
1941, Calcutta became very important to the Allies. With the fall of
Burma in 1942, Calcutta became the easterly Allied front against the
Japanese. The colonial administration had to defend Calcutta at all
costs, and cut the Japanese access to any resources—especially food.
Surplus production from all districts of Bengal was directed to
Calcutta. The famine reached its pinnacle in 1943. The estimated number
of deaths was about five million, mostly from rural Bengal.
No wonder thakuma was obsessed with reducing wastage. She lived in rural
Bengal, and her life must have revolved around food shortage, even
though she never really talked about it. She told us stories about
ghosts who stole leftover food from plates, or ghosts who raided the
larder. There were endless tales of offending the goddess Annapurna, who
punished little girls who didn't eat everything that was on their
plates. We were always afraid that Annapurna or some ghost would find
out that we had secretly thrown away some food and she would punish us.
We were made to associate wasting food with immorality.
It took me very long to understand how my thakuma's fixation had also
shaped my own disposition. Wasting food bothers me much more than I am
willing to acknowledge. I remember being extremely agitated while
watching an American show where a teenage girl threw away a whole tray
of cupcakes because they were delicious, and eating them would make her
fat. I found myself yelling at the screen, "Freeze them, give them away.
Don't do it."
We now live in a culture where wastage is normal. It is very difficult
to discuss food wastage without sounding sanctimonious or preachy. The
adage, "eat up your veggies because children in Africa are going
hungry", doesn't work. We have taken our privileges for granted, and
hunger is often a choice for many. In these times of excess, famine is
unimaginable. All that lingers on is a lonely, dying memory of being
hungry long ago. Very, very hungry.
Aditi Sen is a historian based in Queen's University, Canada.
Sunday, August 20, 2017
what is this
Hinduism gave itself no name, because it set itself no sectarian limits;
it claimed no universal adhesion, asserted no sole infallible dogma, set
up no single narrow path or gate of salvation; it was less a creed or
cult than a continuously enlarging tradition of the God ward endeavor of
the human spirit. An immense many-sided and many staged provision for a
spiritual self-building and self-finding, it had some right to speak of
itself by the only name it knew, the eternal religion, Santana Dharma.
Now just here is the first baffling difficulty over which the European
mind stumbles; for it finds itself unable to make out what Hindu
religion is.... How can there be a religion which has no rigid dogmas
demanding belief on pain of eternal damnation, no theological
postulates, even no fixed theology, no credo, distinguishing it from
antagonistic or rival religions? How can there be a religion which has
no papal head, no governing ecclesiastic body, no church, chapel or
congregational system, no binding religious form of any kind obligatory
on all its adherents, no one administration and discipline? For the
Hindu priests are mere ceremonial officiants without any ecclesiastical
authority or disciplinary powers and the Pundits are mere interpreters
of the Shastra, not the law-givers of the religion or its rulers.
How again can Hinduism be called a religion when it admits all beliefs,
allowing even a kind of high-reaching atheism and agnosticism and
permits all possible spiritual experiences, all kinds of religious
adventures? -- Sri Aurobindo, India's Rebirth
it claimed no universal adhesion, asserted no sole infallible dogma, set
up no single narrow path or gate of salvation; it was less a creed or
cult than a continuously enlarging tradition of the God ward endeavor of
the human spirit. An immense many-sided and many staged provision for a
spiritual self-building and self-finding, it had some right to speak of
itself by the only name it knew, the eternal religion, Santana Dharma.
Now just here is the first baffling difficulty over which the European
mind stumbles; for it finds itself unable to make out what Hindu
religion is.... How can there be a religion which has no rigid dogmas
demanding belief on pain of eternal damnation, no theological
postulates, even no fixed theology, no credo, distinguishing it from
antagonistic or rival religions? How can there be a religion which has
no papal head, no governing ecclesiastic body, no church, chapel or
congregational system, no binding religious form of any kind obligatory
on all its adherents, no one administration and discipline? For the
Hindu priests are mere ceremonial officiants without any ecclesiastical
authority or disciplinary powers and the Pundits are mere interpreters
of the Shastra, not the law-givers of the religion or its rulers.
How again can Hinduism be called a religion when it admits all beliefs,
allowing even a kind of high-reaching atheism and agnosticism and
permits all possible spiritual experiences, all kinds of religious
adventures? -- Sri Aurobindo, India's Rebirth
Sunday, August 6, 2017
Silver in rice
The Hindu
A rice variety originally from West Bengal is able to accumulate the
metal in its grain, IIT researchers find
It is a rice variety with a silver touch, literally. Garib-sal, one of
505 types of rice plants tested by scientists, is capable of absorbing
silver found naturally in soil and accumulating it in the grain to
unusually high levels of 15 mg per kg.
The rice was able to accumulate high quantities of silver even when the
soil contained only about 0.15 mg per kg.
The unusual accumulation of silver in the grain and other parts of the
plant, researchers say, throws open the possibility of commercial
extraction of the metal through farming.
The maximum concentration of silver in the plant is in the grains.
Silver accumulation is largely in the bran of the rice grain, and once
polished, the silver in the grain is reduced significantly.
Polishing grain is crucial
It is not, however, for consumption as food. "We do not advocate
consumption of the unpolished rice as staple food. If the rice is
polished very well then it may not lead to silver toxicity," says Prof.
T. Pradeep from the Department of Chemistry, Indian Institute of
Technology Madras, who authored the research.
Silver is not known to accumulate in the reproductive tissues of any
cereal, and in agricultural crops the amount of silver that gets
accumulated is less than 1 mg per kg of dry weight of the plant.
Researchers at IIT Madras stumbled upon the rice variety while screening
for different metal ions in the 505 rice varieties. Only nine showed
high silver accumulation, with Garib-sal the highest.
The rice varieties are maintained by Dr. Debal Deb, head, Centre of
Interdisciplinary Studies, Kolkata, as part of rice variety conservation
efforts. Garib-sal used to be grown by farmers in Purulia, West Bengal.
The researchers tested Garib-sal's ability to accumulate silver even
when grown in soils with very low silver concentration. Even when the
soil contains only about 0.01 mg of silver per kg, the rice plant was
able to concentrate 0.20 mg of silver per kg in the grains.
"The rice variety has the ability to accumulate silver about 100 times
more than any other rice," says Prof. T. Pradeep. The variety was
cultivated in the farm for three successive years in soil containing
about 0.15 mg per kg and the uptake and accumulation of the noble metal
was nearly the same.
Garib-sal accumulated 50 times more silver than another type in control
tests.
A rice variety originally from West Bengal is able to accumulate the
metal in its grain, IIT researchers find
It is a rice variety with a silver touch, literally. Garib-sal, one of
505 types of rice plants tested by scientists, is capable of absorbing
silver found naturally in soil and accumulating it in the grain to
unusually high levels of 15 mg per kg.
The rice was able to accumulate high quantities of silver even when the
soil contained only about 0.15 mg per kg.
The unusual accumulation of silver in the grain and other parts of the
plant, researchers say, throws open the possibility of commercial
extraction of the metal through farming.
The maximum concentration of silver in the plant is in the grains.
Silver accumulation is largely in the bran of the rice grain, and once
polished, the silver in the grain is reduced significantly.
Polishing grain is crucial
It is not, however, for consumption as food. "We do not advocate
consumption of the unpolished rice as staple food. If the rice is
polished very well then it may not lead to silver toxicity," says Prof.
T. Pradeep from the Department of Chemistry, Indian Institute of
Technology Madras, who authored the research.
Silver is not known to accumulate in the reproductive tissues of any
cereal, and in agricultural crops the amount of silver that gets
accumulated is less than 1 mg per kg of dry weight of the plant.
Researchers at IIT Madras stumbled upon the rice variety while screening
for different metal ions in the 505 rice varieties. Only nine showed
high silver accumulation, with Garib-sal the highest.
The rice varieties are maintained by Dr. Debal Deb, head, Centre of
Interdisciplinary Studies, Kolkata, as part of rice variety conservation
efforts. Garib-sal used to be grown by farmers in Purulia, West Bengal.
The researchers tested Garib-sal's ability to accumulate silver even
when grown in soils with very low silver concentration. Even when the
soil contains only about 0.01 mg of silver per kg, the rice plant was
able to concentrate 0.20 mg of silver per kg in the grains.
"The rice variety has the ability to accumulate silver about 100 times
more than any other rice," says Prof. T. Pradeep. The variety was
cultivated in the farm for three successive years in soil containing
about 0.15 mg per kg and the uptake and accumulation of the noble metal
was nearly the same.
Garib-sal accumulated 50 times more silver than another type in control
tests.
Tuesday, August 1, 2017
The Intelligent Plant
The New Yorker
A Reporter at Large
December 23 & 30, 2013 Issue
The Intelligent Plant
Scientists debate a new way of understanding flora.
By Michael Pollan
Plants have electrical and chemical signalling systems, may possess
memory, and exhibit brainy behavior in the absence of brains.
Construction by Stephen Doyle / Photograph by Grant Cornett
In 1973, a book claiming that plants were sentient beings that feel
emotions, prefer classical music to rock and roll, and can respond to
the unspoken thoughts of humans hundreds of miles away landed on the New
York Times best-seller list for nonfiction. "The Secret Life of Plants,"
by Peter Tompkins and Christopher Bird, presented a beguiling mashup of
legitimate plant science, quack experiments, and mystical nature worship
that captured the public imagination at a time when New Age thinking was
seeping into the mainstream. The most memorable passages described the
experiments of a former C.I.A. polygraph expert named Cleve Backster,
who, in 1966, on a whim, hooked up a galvanometer to the leaf of a
dracaena, a houseplant that he kept in his office. To his astonishment,
Backster found that simply by imagining the dracaena being set on fire
he could make it rouse the needle of the polygraph machine, registering
a surge of electrical activity suggesting that the plant felt stress.
"Could the plant have been reading his mind?" the authors ask. "Backster
felt like running into the street and shouting to the world, 'Plants can
think!' "
Backster and his collaborators went on to hook up polygraph machines to
dozens of plants, including lettuces, onions, oranges, and bananas. He
claimed that plants reacted to the thoughts (good or ill) of humans in
close proximity and, in the case of humans familiar to them, over a
great distance. In one experiment designed to test plant memory,
Backster found that a plant that had witnessed the murder (by stomping)
of another plant could pick out the killer from a lineup of six
suspects, registering a surge of electrical activity when the murderer
was brought before it. Backster's plants also displayed a strong
aversion to interspecies violence. Some had a stressful response when an
egg was cracked in their presence, or when live shrimp were dropped into
boiling water, an experiment that Backster wrote up for the
International Journal of Parapsychology, in 1968.
In the ensuing years, several legitimate plant scientists tried to
reproduce the "Backster effect" without success. Much of the science in
"The Secret Life of Plants" has been discredited. But the book had made
its mark on the culture. Americans began talking to their plants and
playing Mozart for them, and no doubt many still do. This might seem
harmless enough; there will probably always be a strain of romanticism
running through our thinking about plants. (Luther Burbank and George
Washington Carver both reputedly talked to, and listened to, the plants
they did such brilliant work with.) But in the view of many plant
scientists "The Secret Life of Plants" has done lasting damage to their
field. According to Daniel Chamovitz, an Israeli biologist who is the
author of the recent book "What a Plant Knows," Tompkins and Bird
"stymied important research on plant behavior as scientists became wary
of any studies that hinted at parallels between animal senses and plant
senses." Others contend that "The Secret Life of Plants" led to
"self-censorship" among researchers seeking to explore the "possible
homologies between neurobiology and phytobiology"; that is, the
possibility that plants are much more intelligent and much more like us
than most people think—capable of cognition, communication, information
processing, computation, learning, and memory.
The quotation about self-censorship appeared in a controversial 2006
article in Trends in Plant Science proposing a new field of inquiry that
the authors, perhaps somewhat recklessly, elected to call "plant
neurobiology." The six authors—among them Eric D. Brenner, an American
plant molecular biologist; Stefano Mancuso, an Italian plant
physiologist; František Baluška, a Slovak cell biologist; and Elizabeth
Van Volkenburgh, an American plant biologist—argued that the
sophisticated behaviors observed in plants cannot at present be
completely explained by familiar genetic and biochemical mechanisms.
Plants are able to sense and optimally respond to so many environmental
variables—light, water, gravity, temperature, soil structure, nutrients,
toxins, microbes, herbivores, chemical signals from other plants—that
there may exist some brainlike information-processing system to
integrate the data and coördinate a plant's behavioral response. The
authors pointed out that electrical and chemical signalling systems have
been identified in plants which are homologous to those found in the
nervous systems of animals. They also noted that neurotransmitters such
as serotonin, dopamine, and glutamate have been found in plants, though
their role remains unclear.
Hence the need for plant neurobiology, a new field "aimed at
understanding how plants perceive their circumstances and respond to
environmental input in an integrated fashion." The article argued that
plants exhibit intelligence, defined by the authors as "an intrinsic
ability to process information from both abiotic and biotic stimuli that
allows optimal decisions about future activities in a given
environment." Shortly before the article's publication, the Society for
Plant Neurobiology held its first meeting, in Florence, in 2005. A new
scientific journal, with the less tendentious title Plant Signaling &
Behavior, appeared the following year.
Depending on whom you talk to in the plant sciences today, the field of
plant neurobiology represents either a radical new paradigm in our
understanding of life or a slide back down into the murky scientific
waters last stirred up by "The Secret Life of Plants." Its proponents
believe that we must stop regarding plants as passive objects—the mute,
immobile furniture of our world—and begin to treat them as protagonists
in their own dramas, highly skilled in the ways of contending in nature.
They would challenge contemporary biology's reductive focus on cells and
genes and return our attention to the organism and its behavior in the
environment. It is only human arrogance, and the fact that the lives of
plants unfold in what amounts to a much slower dimension of time, that
keep us from appreciating their intelligence and consequent success.
Plants dominate every terrestrial environment, composing ninety-nine per
cent of the biomass on earth. By comparison, humans and all the other
animals are, in the words of one plant neurobiologist, "just traces."
[cartoon id="a16804"]
Many plant scientists have pushed back hard against the nascent field,
beginning with a tart, dismissive letter in response to the Brenner
manifesto, signed by thirty-six prominent plant scientists (Alpi et al.,
in the literature) and published in Trends in Plant Science. "We begin
by stating simply that there is no evidence for structures such as
neurons, synapses or a brain in plants," the authors wrote. No such
claim had actually been made—the manifesto had spoken only of
"homologous" structures—but the use of the word "neurobiology" in the
absence of actual neurons was apparently more than many scientists could
bear.
"Yes, plants have both short- and long-term electrical signalling, and
they use some neurotransmitter-like chemicals as chemical signals,"
Lincoln Taiz, an emeritus professor of plant physiology at U.C. Santa
Cruz and one of the signers of the Alpi letter, told me. "But the
mechanisms are quite different from those of true nervous systems." Taiz
says that the writings of the plant neurobiologists suffer from
"over-interpretation of data, teleology, anthropomorphizing,
philosophizing, and wild speculations." He is confident that eventually
the plant behaviors we can't yet account for will be explained by the
action of chemical or electrical pathways, without recourse to
"animism." Clifford Slayman, a professor of cellular and molecular
physiology at Yale, who also signed the Alpi letter (and who helped
discredit Tompkins and Bird), was even more blunt. " 'Plant
intelligence' is a foolish distraction, not a new paradigm," he wrote in
a recent e-mail. Slayman has referred to the Alpi letter as "the last
serious confrontation between the scientific community and the nuthouse
on these issues." Scientists seldom use such language when talking about
their colleagues to a journalist, but this issue generates strong
feelings, perhaps because it smudges the sharp line separating the
animal kingdom from the plant kingdom. The controversy is less about the
remarkable discoveries of recent plant science than about how to
interpret and name them: whether behaviors observed in plants which look
very much like learning, memory, decision-making, and intelligence
deserve to be called by those terms or whether those words should be
reserved exclusively for creatures with brains.
No one I spoke to in the loose, interdisciplinary group of scientists
working on plant intelligence claims that plants have telekinetic powers
or feel emotions. Nor does anyone believe that we will locate a
walnut-shaped organ somewhere in plants which processes sensory data and
directs plant behavior. More likely, in the scientists' view,
intelligence in plants resembles that exhibited in insect colonies,
where it is thought to be an emergent property of a great many mindless
individuals organized in a network. Much of the research on plant
intelligence has been inspired by the new science of networks,
distributed computing, and swarm behavior, which has demonstrated some
of the ways in which remarkably brainy behavior can emerge in the
absence of actual brains.
"If you are a plant, having a brain is not an advantage," Stefano
Mancuso points out. Mancuso is perhaps the field's most impassioned
spokesman for the plant point of view. A slight, bearded Calabrian in
his late forties, he comes across more like a humanities professor than
like a scientist. When I visited him earlier this year at the
International Laboratory of Plant Neurobiology, at the University of
Florence, he told me that his conviction that humans grossly
underestimate plants has its origins in a science-fiction story he
remembers reading as a teen-ager. A race of aliens living in a radically
sped-up dimension of time arrive on Earth and, unable to detect any
movement in humans, come to the logical conclusion that we are "inert
material" with which they may do as they please. The aliens proceed
ruthlessly to exploit us. (Mancuso subsequently wrote to say that the
story he recounted was actually a mangled recollection of an early "Star
Trek" episode called "Wink of an Eye.")
In Mancuso's view, our "fetishization" of neurons, as well as our
tendency to equate behavior with mobility, keeps us from appreciating
what plants can do. For instance, since plants can't run away and
frequently get eaten, it serves them well not to have any irreplaceable
organs. "A plant has a modular design, so it can lose up to ninety per
cent of its body without being killed," he said. "There's nothing like
that in the animal world. It creates a resilience."
Indeed, many of the most impressive capabilities of plants can be traced
to their unique existential predicament as beings rooted to the ground
and therefore unable to pick up and move when they need something or
when conditions turn unfavorable. The "sessile life style," as plant
biologists term it, calls for an extensive and nuanced understanding of
one's immediate environment, since the plant has to find everything it
needs, and has to defend itself, while remaining fixed in place. A
highly developed sensory apparatus is required to locate food and
identify threats. Plants have evolved between fifteen and twenty
distinct senses, including analogues of our five: smell and taste (they
sense and respond to chemicals in the air or on their bodies); sight
(they react differently to various wavelengths of light as well as to
shadow); touch (a vine or a root "knows" when it encounters a solid
object); and, it has been discovered, sound. In a recent experiment,
Heidi Appel, a chemical ecologist at the University of Missouri, found
that, when she played a recording of a caterpillar chomping a leaf for a
plant that hadn't been touched, the sound primed the plant's genetic
machinery to produce defense chemicals. Another experiment, done in
Mancuso's lab and not yet published, found that plant roots would seek
out a buried pipe through which water was flowing even if the exterior
of the pipe was dry, which suggested that plants somehow "hear" the
sound of flowing water.
The sensory capabilities of plant roots fascinated Charles Darwin, who
in his later years became increasingly passionate about plants; he and
his son Francis performed scores of ingenious experiments on plants.
Many involved the root, or radicle, of young plants, which the Darwins
demonstrated could sense light, moisture, gravity, pressure, and several
other environmental qualities, and then determine the optimal trajectory
for the root's growth. The last sentence of Darwin's 1880 book, "The
Power of Movement in Plants," has assumed scriptural authority for some
plant neurobiologists: "It is hardly an exaggeration to say that the tip
of the radicle . . . having the power of directing the movements of the
adjoining parts, acts like the brain of one of the lower animals; the
brain being seated within the anterior end of the body, receiving
impressions from the sense organs and directing the several movements."
Darwin was asking us to think of the plant as a kind of upside-down
animal, with its main sensory organs and "brain" on the bottom,
underground, and its sexual organs on top. [cartoon id="a17919"]
Scientists have since found that the tips of plant roots, in addition to
sensing gravity, moisture, light, pressure, and hardness, can also sense
volume, nitrogen, phosphorus, salt, various toxins, microbes, and
chemical signals from neighboring plants. Roots about to encounter an
impenetrable obstacle or a toxic substance change course before they
make contact with it. Roots can tell whether nearby roots are self or
other and, if other, kin or stranger. Normally, plants compete for root
space with strangers, but, when researchers put four closely related
Great Lakes sea-rocket plants (Cakile edentula) in the same pot, the
plants restrained their usual competitive behaviors and shared
resources.
Somehow, a plant gathers and integrates all this information about its
environment, and then "decides"—some scientists deploy the quotation
marks, indicating metaphor at work; others drop them—in precisely what
direction to deploy its roots or its leaves. Once the definition of
"behavior" expands to include such things as a shift in the trajectory
of a root, a reallocation of resources, or the emission of a powerful
chemical, plants begin to look like much more active agents, responding
to environmental cues in ways more subtle or adaptive than the word
"instinct" would suggest. "Plants perceive competitors and grow away
from them," Rick Karban, a plant ecologist at U.C. Davis, explained,
when I asked him for an example of plant decision-making. "They are more
leery of actual vegetation than they are of inanimate objects, and they
respond to potential competitors before actually being shaded by them."
These are sophisticated behaviors, but, like most plant behaviors, to an
animal they're either invisible or really, really slow.
The sessile life style also helps account for plants' extraordinary gift
for biochemistry, which far exceeds that of animals and, arguably, of
human chemists. (Many drugs, from aspirin to opiates, derive from
compounds designed by plants.) Unable to run away, plants deploy a
complex molecular vocabulary to signal distress, deter or poison
enemies, and recruit animals to perform various services for them. A
recent study in Science found that the caffeine produced by many plants
may function not only as a defense chemical, as had previously been
thought, but in some cases as a psychoactive drug in their nectar. The
caffeine encourages bees to remember a particular plant and return to
it, making them more faithful and effective pollinators.
One of the most productive areas of plant research in recent years has
been plant signalling. Since the early nineteen-eighties, it has been
known that when a plant's leaves are infected or chewed by insects they
emit volatile chemicals that signal other leaves to mount a defense.
Sometimes this warning signal contains information about the identity of
the insect, gleaned from the taste of its saliva. Depending on the plant
and the attacker, the defense might involve altering the leaf's flavor
or texture, or producing toxins or other compounds that render the
plant's flesh less digestible to herbivores. When antelopes browse
acacia trees, the leaves produce tannins that make them unappetizing and
difficult to digest. When food is scarce and acacias are overbrowsed, it
has been reported, the trees produce sufficient amounts of toxin to kill
the animals.
Perhaps the cleverest instance of plant signalling involves two insect
species, the first in the role of pest and the second as its
exterminator. Several species, including corn and lima beans, emit a
chemical distress call when attacked by caterpillars. Parasitic wasps
some distance away lock in on that scent, follow it to the afflicted
plant, and proceed to slowly destroy the caterpillars. Scientists call
these insects "plant bodyguards."
Plants speak in a chemical vocabulary we can't directly perceive or
comprehend. The first important discoveries in plant communication were
made in the lab in the nineteen-eighties, by isolating plants and their
chemical emissions in Plexiglas chambers, but Rick Karban, the U.C.
Davis ecologist, and others have set themselves the messier task of
studying how plants exchange chemical signals outdoors, in a natural
setting. Recently, I visited Karban's study plot at the University of
California's Sagehen Creek Field Station, a few miles outside Truckee.
On a sun-flooded hillside high in the Sierras, he introduced me to the
ninety-nine sagebrush plants—low, slow-growing gray-green shrubs marked
with plastic flags—that he and his colleagues have kept under close
surveillance for more than a decade.
Karban, a fifty-nine-year-old former New Yorker, is slender, with a
thatch of white curls barely contained by a floppy hat. He has shown
that when sagebrush leaves are clipped in the spring—simulating an
insect attack that triggers the release of volatile chemicals—both the
clipped plant and its unclipped neighbors suffer significantly less
insect damage over the season. Karban believes that the plant is
alerting all its leaves to the presence of a pest, but its neighbors
pick up the signal, too, and gird themselves against attack. "We think
the sagebrush are basically eavesdropping on one another," Karban said.
He found that the more closely related the plants the more likely they
are to respond to the chemical signal, suggesting that plants may
display a form of kin recognition. Helping out your relatives is a good
way to improve the odds that your genes will survive.
The field work and data collection that go into making these discoveries
are painstaking in the extreme. At the bottom of a meadow raked by the
slanted light of late summer, two collaborators from Japan, Kaori
Shiojiri and Satomi Ishizaki, worked in the shade of a small pine,
squatting over branches of sagebrush that Karban had tagged and cut.
Using clickers, they counted every trident-shaped leaf on every branch,
and then counted and recorded every instance of leaf damage, one column
for insect bites, another for disease. At the top of the meadow, another
collaborator, James Blande, a chemical ecologist from England, tied
plastic bags around sagebrush stems and inflated the bags with filtered
air. After waiting twenty minutes for the leaves to emit their
volatiles, he pumped the air through a metal cylinder containing an
absorbent material that collected the chemical emissions. At the lab, a
gas chromatograph-mass spectrometer would yield a list of the compounds
collected—more than a hundred in all. Blande offered to let me put my
nose in one of the bags; the air was powerfully aromatic, with a scent
closer to aftershave than to perfume. Gazing across the meadow of
sagebrush, I found it difficult to imagine the invisible chemical
chatter, including the calls of distress, going on all around—or that
these motionless plants were engaged in any kind of "behavior" at all.
Research on plant communication may someday benefit farmers and their
crops. Plant-distress chemicals could be used to prime plant defenses,
reducing the need for pesticides. Jack Schultz, a chemical ecologist at
the University of Missouri, who did some of the pioneering work on plant
signalling in the early nineteen-eighties, is helping to develop a
mechanical "nose" that, attached to a tractor and driven through a
field, could help farmers identify plants under insect attack, allowing
them to spray pesticides only when and where they are needed. [cartoon
id="a17864"]
Karban told me that, in the nineteen-eighties, people working on plant
communication faced some of the same outrage that scientists working on
plant intelligence (a term he cautiously accepts) do today. "This stuff
has been enormously contentious," he says, referring to the early days
of research into plant communication, work that is now generally
accepted. "It took me years to get some of these papers published.
People would literally be screaming at one another at scientific
meetings." He added, "Plant scientists in general are incredibly
conservative. We all think we want to hear novel ideas, but we don't,
not really."
I first met Karban at a scientific meeting in Vancouver last July, when
he presented a paper titled "Plant Communication and Kin Recognition in
Sagebrush." The meeting would have been the sixth gathering of the
Society for Plant Neurobiology, if not for the fact that, under pressure
from certain quarters of the scientific establishment, the group's name
had been changed four years earlier to the less provocative Society for
Plant Signaling and Behavior. The plant biologist Elizabeth Van
Volkenburgh, of the University of Washington, who was one of the
founders of the society, told me that the name had been changed after a
lively internal debate; she felt that jettisoning "neurobiology" was
probably for the best. "I was told by someone at the National Science
Foundation that the N.S.F. would never fund anything with the words
'plant neurobiology' in it. He said, and I quote, ' "Neuro" belongs to
animals.' " (An N.S.F. spokesperson said that, while the society is not
eligible for funding by the foundation's neurobiology program, "the
N.S.F. does not have a boycott of any sort against the society.") Two of
the society's co-founders, Stefano Mancuso and František Baluška, argued
strenuously against the name change, and continue to use the term "plant
neurobiology" in their own work and in the names of their labs.
The meeting consisted of three days of PowerPoint presentations
delivered in a large, modern lecture hall at the University of British
Columbia before a hundred or so scientists. Most of the papers were
highly technical presentations on plant signalling—the kind of
incremental science that takes place comfortably within the confines of
an established scientific paradigm, which plant signalling has become.
But a handful of speakers presented work very much within the new
paradigm of plant intelligence, and they elicited strong reactions.
The most controversial presentation was "Animal-Like Learning in Mimosa
Pudica," an unpublished paper by Monica Gagliano, a
thirty-seven-year-old animal ecologist at the University of Western
Australia who was working in Mancuso's lab in Florence. Gagliano, who is
tall, with long brown hair parted in the middle, based her experiment on
a set of protocols commonly used to test learning in animals. She
focussed on an elementary type of learning called "habituation," in
which an experimental subject is taught to ignore an irrelevant
stimulus. "Habituation enables an organism to focus on the important
information, while filtering out the rubbish," Gagliano explained to the
audience of plant scientists. How long does it take the animal to
recognize that a stimulus is "rubbish," and then how long will it
remember what it has learned? Gagliano's experimental question was
bracing: Could the same thing be done with a plant?
Mimosa pudica, also called the "sensitive plant," is that rare plant
species with a behavior so speedy and visible that animals can observe
it; the Venus flytrap is another. When the fernlike leaves of the mimosa
are touched, they instantly fold up, presumably to frighten insects. The
mimosa also collapses its leaves when the plant is dropped or jostled.
Gagliano potted fifty-six mimosa plants and rigged a system to drop them
from a height of fifteen centimetres every five seconds. Each "training
session" involved sixty drops. She reported that some of the mimosas
started to reopen their leaves after just four, five, or six drops, as
if they had concluded that the stimulus could be safely ignored. "By the
end, they were completely open," Gagliano said to the audience. "They
couldn't care less anymore."
Was it just fatigue? Apparently not: when the plants were shaken, they
again closed up. " 'Oh, this is something new,' " Gagliano said,
imagining these events from the plants' point of view. "You see, you
want to be attuned to something new coming in. Then we went back to the
drops, and they didn't respond." Gagliano reported that she retested her
plants after a week and found that they continued to disregard the drop
stimulus, indicating that they "remembered" what they had learned. Even
after twenty-eight days, the lesson had not been forgotten. She reminded
her colleagues that, in similar experiments with bees, the insects
forgot what they had learned after just forty-eight hours. Gagliano
concluded by suggesting that "brains and neurons are a sophisticated
solution but not a necessary requirement for learning," and that there
is "some unifying mechanism across living systems that can process
information and learn."
A lively exchange followed. Someone objected that dropping a plant was
not a relevant trigger, since that doesn't happen in nature. Gagliano
pointed out that electric shock, an equally artificial trigger, is often
used in animal-learning experiments. Another scientist suggested that
perhaps her plants were not habituated, just tuckered out. She argued
that twenty-eight days would be plenty of time to rebuild their energy
reserves.
On my way out of the lecture hall, I bumped into Fred Sack, a prominent
botanist at the University of British Columbia. I asked him what he
thought of Gagliano's presentation. "Bullshit," he replied. He explained
that the word "learning" implied a brain and should be reserved for
animals: "Animals can exhibit learning, but plants evolve adaptations."
He was making a distinction between behavioral changes that occur within
the lifetime of an organism and those which arise across generations. At
lunch, I sat with a Russian scientist, who was equally dismissive. "It's
not learning," he said. "So there's nothing to discuss." [cartoon
id="a17930"]
Later that afternoon, Gagliano seemed both stung by some of the
reactions to her presentation and defiant. Adaptation is far too slow a
process to explain the behavior she had observed, she told me. "How can
they be adapted to something they have never experienced in their real
world?" She noted that some of her plants learned faster than others,
evidence that "this is not an innate or programmed response." Many of
the scientists in her audience were just getting used to the ideas of
plant "behavior" and "memory" (terms that even Fred Sack said he was
willing to accept); using words like "learning" and "intelligence" in
plants struck them, in Sack's words, as "inappropriate" and "just
weird." When I described the experiment to Lincoln Taiz, he suggested
the words "habituation" or "desensitization" would be more appropriate
than "learning." Gagliano said that her mimosa paper had been rejected
by ten journals: "None of the reviewers had problems with the data."
Instead, they balked at the language she used to describe the data. But
she didn't want to change it. "Unless we use the same language to
describe the same behavior"—exhibited by plants and animals—"we can't
compare it," she said.
Rick Karban consoled Gagliano after her talk. "I went through the same
thing, just getting totally hammered," he told her. "But you're doing
good work. The system is just not ready." When I asked him what he
thought of Gagliano's paper, he said, "I don't know if she's got
everything nailed down, but it's a very cool idea that deserves to get
out there and be discussed. I hope she doesn't get discouraged."
Scientists are often uncomfortable talking about the role of metaphor
and imagination in their work, yet scientific progress often depends on
both. "Metaphors help stimulate the investigative imagination of good
scientists," the British plant scientist Anthony Trewavas wrote in a
spirited response to the Alpi letter denouncing plant neurobiology.
"Plant neurobiology" is obviously a metaphor—plants don't possess the
type of excitable, communicative cells we call neurons. Yet the
introduction of the term has raised a series of questions and inspired a
set of experiments that promise to deepen our understanding not only of
plants but potentially also of brains. If there are other ways of
processing information, other kinds of cells and cell networks that can
somehow give rise to intelligent behavior, then we may be more inclined
to ask, with Mancuso, "What's so special about neurons?"
Mancuso is the poet-philosopher of the movement, determined to win for
plants the recognition they deserve and, perhaps, bring humans down a
peg in the process. His somewhat grandly named International Laboratory
of Plant Neurobiology, a few miles outside Florence, occupies a modest
suite of labs and offices in a low-slung modern building. Here a handful
of collaborators and graduate students work on the experiments Mancuso
devises to test the intelligence of plants. Giving a tour of the labs,
he showed me maize plants, grown under lights, that were being taught to
ignore shadows; a poplar sapling hooked up to a galvanometer to measure
its response to air pollution; and a chamber in which a PTR-TOF
machine—an advanced kind of mass spectrometer—continuously read all the
volatiles emitted by a succession of plants, from poplars and tobacco
plants to peppers and olive trees. "We are making a dictionary of each
species' entire chemical vocabulary," he explained. He estimates that a
plant has three thousand chemicals in its vocabulary, while, he said
with a smile, "the average student has only seven hundred words."
Mancuso is fiercely devoted to plants—a scientist needs to "love" his
subject in order to do it justice, he says. He is also gentle and
unassuming, even when what he is saying is outrageous. In the corner of
his office sits a forlorn Ficus benjamina, or weeping fig, and on the
walls are photographs of Mancuso in an astronaut's jumpsuit floating in
the cabin of a zero-gravity aircraft; he has collaborated with the
European Space Agency, which has supported his research on plant
behavior in micro- and hyper-gravity. (One of his experiments was
carried on board the last flight of the space shuttle Endeavor, in May
of 2011.) A decade ago, Mancuso persuaded a Florentine bank foundation
to underwrite much of his research and help launch the Society for Plant
Neurobiology; his lab also receives grants from the European Union.
Early in our conversation, I asked Mancuso for his definition of
"intelligence." Spending so much time with the plant neurobiologists, I
could feel my grasp on the word getting less sure. It turns out that I
am not alone: philosophers and psychologists have been arguing over the
definition of intelligence for at least a century, and whatever
consensus there may once have been has been rapidly slipping away. Most
definitions of intelligence fall into one of two categories. The first
is worded so that intelligence requires a brain; the definition refers
to intrinsic mental qualities such as reason, judgment, and abstract
thought. The second category, less brain-bound and metaphysical,
stresses behavior, defining intelligence as the ability to respond in
optimal ways to the challenges presented by one's environment and
circumstances. Not surprisingly, the plant neurobiologists jump into
this second camp.
"I define it very simply," Mancuso said. "Intelligence is the ability to
solve problems." In place of a brain, "what I am looking for is a
distributed sort of intelligence, as we see in the swarming of birds."
In a flock, each bird has only to follow a few simple rules, such as
maintaining a prescribed distance from its neighbor, yet the collective
effect of a great many birds executing a simple algorithm is a complex
and supremely well-coördinated behavior. Mancuso's hypothesis is that
something similar is at work in plants, with their thousands of root
tips playing the role of the individual birds—gathering and assessing
data from the environment and responding in local but coördinated ways
that benefit the entire organism.
"Neurons perhaps are overrated," Mancuso said. "They're really just
excitable cells." Plants have their own excitable cells, many of them in
a region just behind the root tip. Here Mancuso and his frequent
collaborator, František Baluška, have detected unusually high levels of
electrical activity and oxygen consumption. They've hypothesized in a
series of papers that this so-called "transition zone" may be the locus
of the "root brain" first proposed by Darwin. The idea remains unproved
and controversial. "What's going on there is not well understood,"
Lincoln Taiz told me, "but there is no evidence it is a command center."
How plants do what they do without a brain—what Anthony Trewavas has
called their "mindless mastery"—raises questions about how our brains do
what they do. When I asked Mancuso about the function and location of
memory in plants, he speculated about the possible role of calcium
channels and other mechanisms, but then he reminded me that mystery
still surrounds where and how our memories are stored: "It could be the
same kind of machinery, and figuring it out in plants may help us figure
it out in humans." [cartoon id="a17948"]
The hypothesis that intelligent behavior in plants may be an emergent
property of cells exchanging signals in a network might sound
far-fetched, yet the way that intelligence emerges from a network of
neurons may not be very different. Most neuroscientists would agree
that, while brains considered as a whole function as centralized command
centers for most animals, within the brain there doesn't appear to be
any command post; rather, one finds a leaderless network. That sense we
get when we think about what might govern a plant—that there is no there
there, no wizard behind the curtain pulling the levers—may apply equally
well to our brains.
In Martin Amis's 1995 novel, "The Information," we meet a character who
aspires to write "The History of Increasing Humiliation," a treatise
chronicling the gradual dethronement of humankind from its position at
the center of the universe, beginning with Copernicus. "Every century we
get smaller," Amis writes. Next came Darwin, who brought the humbling
news that we are the product of the same natural laws that created
animals. In the last century, the formerly sharp lines separating humans
from animals—our monopolies on language, reason, toolmaking, culture,
even self-consciousness—have been blurred, one after another, as science
has granted these capabilities to other animals.
Mancuso and his colleagues are writing the next chapter in "The History
of Increasing Humiliation." Their project entails breaking down the
walls between the kingdoms of plants and animals, and it is proceeding
not only experiment by experiment but also word by word. Start with that
slippery word "intelligence." Particularly when there is no dominant
definition (and when measurements of intelligence, such as I.Q., have
been shown to be culturally biased), it is possible to define
intelligence in a way that either reinforces the boundary between
animals and plants (say, one that entails abstract thought) or
undermines it. Plant neurobiologists have chosen to define intelligence
democratically, as an ability to solve problems or, more precisely, to
respond adaptively to circumstances, including ones unforeseen in the
genome.
"I agree that humans are special," Mancuso says. "We are the first
species able to argue about what intelligence is. But it's the quantity,
not the quality" of intelligence that sets us apart. We exist on a
continuum with the acacia, the radish, and the bacterium. "Intelligence
is a property of life," he says. I asked him why he thinks people have
an easier time granting intelligence to computers than to plants. (Fred
Sack told me that he can abide the term "artificial intelligence,"
because the intelligence in this case is modified by the word
"artificial," but not "plant intelligence." He offered no argument,
except to say, "I'm in the majority in saying it's a little weird.")
Mancuso thinks we're willing to accept artificial intelligence because
computers are our creations, and so reflect our own intelligence back at
us. They are also our dependents, unlike plants: "If we were to vanish
tomorrow, the plants would be fine, but if the plants vanished . . ."
Our dependence on plants breeds a contempt for them, Mancuso believes.
In his somewhat topsy-turvy view, plants "remind us of our weakness."
"Memory" may be an even thornier word to apply across kingdoms, perhaps
because we know so little about how it works. We tend to think of
memories as immaterial, but in animal brains some forms of memory
involve the laying down of new connections in a network of neurons. Yet
there are ways to store information biologically that don't require
neurons. Immune cells "remember" their experience of pathogens, and call
on that memory in subsequent encounters. In plants, it has long been
known that experiences such as stress can alter the molecular wrapping
around the chromosomes; this, in turn, determines which genes will be
silenced and which expressed. This so-called "epigenetic" effect can
persist and sometimes be passed down to offspring. More recently,
scientists have found that life events such as trauma or starvation
produce epigenetic changes in animal brains (coding for high levels of
cortisol, for example) that are long-lasting and can also be passed down
to offspring, a form of memory much like that observed in plants.
While talking with Mancuso, I kept thinking about words like "will,"
"choice," and "intention," which he seemed to attribute to plants rather
casually, almost as if they were acting consciously. At one point, he
told me about the dodder vine, Cuscuta europaea, a parasitic white vine
that winds itself around the stalk of another plant and sucks
nourishment from it. A dodder vine will "choose" among several potential
hosts, assessing, by scent, which offers the best potential nourishment.
Having selected a target, the vine then performs a kind of cost-benefit
calculation before deciding exactly how many coils it should invest—the
more nutrients in the victim, the more coils it deploys. I asked Mancuso
whether he was being literal or metaphorical in attributing intention to
plants.
"Here, I'll show you something," he said. "Then you tell me if plants
have intention." He swivelled his computer monitor around and clicked
open a video.
Time-lapse photography is perhaps the best tool we have to bridge the
chasm between the time scale at which plants live and our own. This
example was of a young bean plant, shot in the lab over two days, one
frame every ten minutes. A metal pole on a dolly stands a couple of feet
away. The bean plant is "looking" for something to climb. Each spring, I
witness the same process in my garden, in real time. I always assumed
that the bean plants simply grow this way or that, until they eventually
bump into something suitable to climb. But Mancuso's video seems to show
that this bean plant "knows" exactly where the metal pole is long before
it makes contact with it. Mancuso speculates that the plant could be
employing a form of echolocation. There is some evidence that plants
make low clicking sounds as their cells elongate; it's possible that
they can sense the reflection of those sound waves bouncing off the
metal pole.
The bean plant wastes no time or energy "looking"—that is,
growing—anywhere but in the direction of the pole. And it is striving
(there is no other word for it) to get there: reaching, stretching,
throwing itself over and over like a fly rod, extending itself a few
more inches with every cast, as it attempts to wrap its curling tip
around the pole. As soon as contact is made, the plant appears to relax;
its clenched leaves begin to flutter mildly. All this may be nothing
more than an illusion of time-lapse photography. Yet to watch the video
is to feel, momentarily, like one of the aliens in Mancuso's formative
science-fiction story, shown a window onto a dimension of time in which
these formerly inert beings come astonishingly to life, seemingly
conscious individuals with intentions. [cartoon id="sipress-2011-05-16"]
In October, I loaded the bean video onto my laptop and drove down to
Santa Cruz to play it for Lincoln Taiz. He began by questioning its
value as scientific data: "Maybe he has ten other videos where the bean
didn't do that. You can't take one interesting variation and generalize
from it." The bean's behavior was, in other words, an anecdote, not a
phenomenon. Taiz also pointed out that the bean in the video was leaning
toward the pole in the first frame. Mancuso then sent me another video
with two perfectly upright bean plants that exhibited very similar
behavior. Taiz was now intrigued. "If he sees that effect consistently,
it would be exciting," he said—but it would not necessarily be evidence
of plant intention. "If the phenomenon is real, it would be classified
as a tropism," such as the mechanism that causes plants to bend toward
light. In this case, the stimulus remains unknown, but tropisms "do not
require one to postulate either intentionality or 'brainlike'
conceptualization," Taiz said. "The burden of proof for the latter
interpretation would clearly be on Stefano."
Perhaps the most troublesome and troubling word of all in thinking about
plants is "consciousness." If consciousness is defined as inward
awareness of oneself experiencing reality—"the feeling of what happens,"
in the words of the neuroscientist Antonio Damasio—then we can
(probably) safely conclude that plants don't possess it. But if we
define the term simply as the state of being awake and aware of one's
environment—"online," as the neuroscientists say—then plants may qualify
as conscious beings, at least according to Mancuso and Baluška. "The
bean knows exactly what is in the environment around it," Mancuso said.
"We don't know how. But this is one of the features of consciousness:
You know your position in the world. A stone does not."
In support of their contention that plants are conscious of their
environment, Mancuso and Baluška point out that plants can be rendered
unconscious by the same anesthetics that put animals out: drugs can
induce in plants an unresponsive state resembling sleep. (A snoozing
Venus flytrap won't notice an insect crossing its threshold.) What's
more, when plants are injured or stressed, they produce a
chemical—ethylene—that works as an anesthetic on animals. When I learned
this startling fact from Baluška in Vancouver, I asked him, gingerly, if
he meant to suggest that plants could feel pain. Baluška, who has a
gruff mien and a large bullet-shaped head, raised one eyebrow and shot
me a look that I took to mean he deemed my question impertinent or
absurd. But apparently not.
"If plants are conscious, then, yes, they should feel pain," he said.
"If you don't feel pain, you ignore danger and you don't survive. Pain
is adaptive." I must have shown some alarm. "That's a scary idea," he
acknowledged with a shrug. "We live in a world where we must eat other
organisms."
Unprepared to consider the ethical implications of plant intelligence, I
could feel my resistance to the whole idea stiffen. Descartes, who
believed that only humans possessed self-consciousness, was unable to
credit the idea that other animals could suffer from pain. So he
dismissed their screams and howls as mere reflexes, as meaningless
physiological noise. Could it be remotely possible that we are now
making the same mistake with plants? That the perfume of jasmine or
basil, or the scent of freshly mowed grass, so sweet to us, is (as the
ecologist Jack Schultz likes to say) the chemical equivalent of a
scream? Or have we, merely by posing such a question, fallen back into
the muddied waters of "The Secret Life of Plants"?
Lincoln Taiz has little patience for the notion of plant pain,
questioning what, in the absence of a brain, would be doing the feeling.
He puts it succinctly: "No brain, no pain." Mancuso is more circumspect.
We can never determine with certainty whether plants feel pain or
whether their perception of injury is sufficiently like that of animals
to be called by the same word. (He and Baluška are careful to write of
"plant-specific pain perception.") "We just don't know, so we must be
silent."
Mancuso believes that, because plants are sensitive and intelligent
beings, we are obliged to treat them with some degree of respect. That
means protecting their habitats from destruction and avoiding practices
such as genetic manipulation, growing plants in monocultures, and
training them in bonsai. But it does not prevent us from eating them.
"Plants evolved to be eaten—it is part of their evolutionary strategy,"
he said. He cited their modular structure and lack of irreplaceable
organs in support of this view.
The central issue dividing the plant neurobiologists from their critics
would appear to be this: Do capabilities such as intelligence, pain
perception, learning, and memory require the existence of a brain, as
the critics contend, or can they be detached from their neurobiological
moorings? The question is as much philosophical as it is scientific,
since the answer depends on how these terms get defined. The proponents
of plant intelligence argue that the traditional definitions of these
terms are anthropocentric—a clever reply to the charges of
anthropomorphism frequently thrown at them. Their attempt to broaden
these definitions is made easier by the fact that the meanings of so
many of these terms are up for grabs. At the same time, since these
words were originally created to describe animal attributes, we
shouldn't be surprised at the awkward fit with plants. It seems likely
that, if the plant neurobiologists were willing to add the prefix
"plant-specific" to intelligence and learning and memory and
consciousness (as Mancuso and Baluška are prepared to do in the case of
pain), then at least some of this "scientific controversy" might
evaporate.
Indeed, I found more consensus on the underlying science than I
expected. Even Clifford Slayman, the Yale biologist who signed the 2007
letter dismissing plant neurobiology, is willing to acknowledge that,
although he doesn't think plants possess intelligence, he does believe
they are capable of "intelligent behavior," in the same way that bees
and ants are. In an e-mail exchange, Slayman made a point of underlining
this distinction: "We do not know what constitutes intelligence, only
what we can observe and judge as intelligent behavior." He defined
"intelligent behavior" as "the ability to adapt to changing
circumstances" and noted that it "must always be measured relative to a
particular environment." Humans may or may not be intrinsically more
intelligent than cats, he wrote, but when a cat is confronted with a
mouse its behavior is likely to be demonstrably more intelligent.
[cartoon id="stevens-2011-05-23"]
Slayman went on to acknowledge that "intelligent behavior could
perfectly well develop without such a nerve center or headquarters or
director or brain—whatever you want to call it. Instead of 'brain,'
think 'network.' It seems to be that many higher organisms are
internally networked in such a way that local changes," such as the way
that roots respond to a water gradient, "cause very local responses
which benefit the entire organism." Seen that way, he added, the outlook
of Mancuso and Trewavas is "pretty much in line with my understanding of
biochemical/biological networks." He pointed out that while it is an
understandable human prejudice to favor the "nerve center" model, we
also have a second, autonomic nervous system governing our digestive
processes, which "operates most of the time without instructions from
higher up." Brains are just one of nature's ways of getting complex jobs
done, for dealing intelligently with the challenges presented by the
environment. But they are not the only way: "Yes, I would argue that
intelligent behavior is a property of life."
To define certain words in such a way as to bring plants and animals
beneath the same semantic umbrella—whether of intelligence or intention
or learning—is a philosophical choice with important consequences for
how we see ourselves in nature. Since "The Origin of Species," we have
understood, at least intellectually, the continuities among life's
kingdoms—that we are all cut from the same fabric of nature. Yet our big
brains, and perhaps our experience of inwardness, allow us to feel that
we must be fundamentally different—suspended above nature and other
species as if by some metaphysical "skyhook," to borrow a phrase from
the philosopher Daniel Dennett. Plant neurobiologists are intent on
taking away our skyhook, completing the revolution that Darwin started
but which remains—psychologically, at least—incomplete.
"What we learned from Darwin is that competence precedes comprehension,"
Dennett said when I called to talk to him about plant neurobiology. Upon
a foundation of the simplest competences—such as the on-off switch in a
computer, or the electrical and chemical signalling of a cell—can be
built higher and higher competences until you wind up with something
that looks very much like intelligence. "The idea that there is a bright
line, with real comprehension and real minds on the far side of the
chasm, and animals or plants on the other—that's an archaic myth." To
say that higher competences such as intelligence, learning, and memory
"mean nothing in the absence of brains" is, in Dennett's view,
"cerebrocentric."
All species face the same existential challenges—obtaining food,
defending themselves, reproducing—but under wildly varying
circumstances, and so they have evolved wildly different tools in order
to survive. Brains come in handy for creatures that move around a lot;
but they're a disadvantage for ones that are rooted in place. Impressive
as it is to us, self-consciousness is just another tool for living, good
for some jobs, unhelpful for others. That humans would rate this
particular adaptation so highly is not surprising, since it has been the
shining destination of our long evolutionary journey, along with the
epiphenomenon of self-consciousness that we call "free will."
In addition to being a plant physiologist, Lincoln Taiz writes about the
history of science. "Starting with Darwin's grandfather, Erasmus," he
told me, "there has been a strain of teleology in the study of plant
biology"—a habit of ascribing purpose or intention to the behavior of
plants. I asked Taiz about the question of "choice," or decision-making,
in plants, as when they must decide between two conflicting
environmental signals—water and gravity, for example.
"Does the plant decide in the same way that we choose at a deli between
a Reuben sandwich or lox and bagel?" Taiz asked. "No, the plant response
is based entirely on the net flow of auxin and other chemical signals.
The verb 'decide' is inappropriate in a plant context. It implies free
will. Of course, one could argue that humans lack free will too, but
that is a separate issue."
I asked Mancuso if he thought that a plant decides in the same way we
might choose at a deli between a Reuben or lox and bagels.
"Yes, in the same way," Mancuso wrote back, though he indicated that he
had no idea what a Reuben was. "Just put ammonium nitrate in the place
of Reuben sandwich (whatever it is) and phosphate instead of salmon, and
the roots will make a decision." But isn't the root responding simply to
the net flow of certain chemicals? "I'm afraid our brain makes decisions
in the same exact way."
"Why would a plant care about Mozart?" the late ethnobotanist Tim
Plowman would reply when asked about the wonders catalogued in "The
Secret Life of Plants." "And even if it did, why should that impress us?
They can eat light, isn't that enough?"
One way to exalt plants is by demonstrating their animal-like
capabilities. But another way is to focus on all the things plants can
do that we cannot. Some scientists working on plant intelligence have
questioned whether the "animal-centric" emphasis, along with the
obsession with the term "neurobiology," has been a mistake and possibly
an insult to the plants. "I have no interest in making plants into
little animals," one scientist wrote during the dustup over what to call
the society. "Plants are unique," another wrote. "There is no reason to
. . . call them demi-animals."
When I met Mancuso for dinner during the conference in Vancouver, he
sounded very much like a plant scientist getting over a case of "brain
envy"—what Taiz had suggested was motivating the plant neurologists. If
we could begin to understand plants on their own terms, he said, "it
would be like being in contact with an alien culture. But we could have
all the advantages of that contact without any of the problems—because
it doesn't want to destroy us!" How do plants do all the amazing things
they do without brains? Without locomotion? By focussing on the
otherness of plants rather than on their likeness, Mancuso suggested, we
stand to learn valuable things and develop important new technologies.
This was to be the theme of his presentation to the conference, the
following morning, on what he called "bioinspiration." How might the
example of plant intelligence help us design better computers, or
robots, or networks?
Mancuso was about to begin a collaboration with a prominent computer
scientist to design a plant-based computer, modelled on the distributed
computing performed by thousands of roots processing a vast number of
environmental variables. His collaborator, Andrew Adamatzky, the
director of the International Center of Unconventional Computing, at the
University of the West of England, has worked extensively with slime
molds, harnessing their maze-navigating and computational abilities.
(Adamatzky's slime molds, which are a kind of amoeba, grow in the
direction of multiple food sources simultaneously, usually oat flakes,
in the process computing and remembering the shortest distance between
any two of them; he has used these organisms to model transportation
networks.) In an e-mail, Adamatzky said that, as a substrate for
biological computing, plants offered both advantages and disadvantages
over slime molds. "Plants are more robust," he wrote, and "can keep
their shape for a very long time," although they are slower-growing and
lack the flexibility of slime molds. But because plants are already
"analog electrical computers," trafficking in electrical inputs and
outputs, he is hopeful that he and Mancuso will be able to harness them
for computational tasks. [cartoon id="vey-2011-04-18"]
Mancuso was also working with Barbara Mazzolai, a
biologist-turned-engineer at the Italian Institute of Technology, in
Genoa, to design what he called a "plantoid": a robot designed on plant
principles. "If you look at the history of robots, they are always based
on animals—they are humanoids or insectoids. If you want something
swimming, you look at a fish. But what about imitating plants instead?
What would that allow you to do? Explore the soil!" With a grant from
the European Union's Future and Emerging Technologies program, their
team is developing a "robotic root" that, using plastics that can
elongate and then harden, will be able to slowly penetrate the soil,
sense conditions, and alter its trajectory accordingly. "If you want to
explore other planets, the best thing is to send plantoids."
The most bracing part of Mancuso's talk on bioinspiration came when he
discussed underground plant networks. Citing the research of Suzanne
Simard, a forest ecologist at the University of British Columbia, and
her colleagues, Mancuso showed a slide depicting how trees in a forest
organize themselves into far-flung networks, using the underground web
of mycorrhizal fungi which connects their roots to exchange information
and even goods. This "wood-wide web," as the title of one paper put it,
allows scores of trees in a forest to convey warnings of insect attacks,
and also to deliver carbon, nitrogen, and water to trees in need.
When I reached Simard by phone, she described how she and her colleagues
track the flow of nutrients and chemical signals through this invisible
underground network. They injected fir trees with radioactive carbon
isotopes, then followed the spread of the isotopes through the forest
community using a variety of sensing methods, including a Geiger
counter. Within a few days, stores of radioactive carbon had been routed
from tree to tree. Every tree in a plot thirty metres square was
connected to the network; the oldest trees functioned as hubs, some with
as many as forty-seven connections. The diagram of the forest network
resembled an airline route map.
The pattern of nutrient traffic showed how "mother trees" were using the
network to nourish shaded seedlings, including their offspring—which the
trees can apparently recognize as kin—until they're tall enough to reach
the light. And, in a striking example of interspecies coöperation,
Simard found that fir trees were using the fungal web to trade nutrients
with paper-bark birch trees over the course of the season. The evergreen
species will tide over the deciduous one when it has sugars to spare,
and then call in the debt later in the season. For the forest community,
the value of this coöperative underground economy appears to be better
over-all health, more total photosynthesis, and greater resilience in
the face of disturbance.
In his talk, Mancuso juxtaposed a slide of the nodes and links in one of
these subterranean forest networks with a diagram of the Internet, and
suggested that in some respects the former was superior. "Plants are
able to create scalable networks of self-maintaining, self-operating,
and self-repairing units," he said. "Plants."
As I listened to Mancuso limn the marvels unfolding beneath our feet, it
occurred to me that plants do have a secret life, and it is even
stranger and more wonderful than the one described by Tompkins and Bird.
When most of us think of plants, to the extent that we think about
plants at all, we think of them as old—holdovers from a simpler,
prehuman evolutionary past. But for Mancuso plants hold the key to a
future that will be organized around systems and technologies that are
networked, decentralized, modular, reiterated, redundant—and green, able
to nourish themselves on light. "Plants are the great symbol of
modernity." Or should be: their brainlessness turns out to be their
strength, and perhaps the most valuable inspiration we can take from
them.
At dinner in Vancouver, Mancuso said, "Since you visited me in Florence,
I came across this sentence of Karl Marx, and I became obsessed with it:
'Everything that is solid melts into air.' Whenever we build anything,
it is inspired by the architecture of our bodies. So it will have a
solid structure and a center, but that is inherently fragile. This is
the meaning of that sentence—'Everything solid melts into air.' So
that's the question: Can we now imagine something completely different,
something inspired instead by plants?" ♦
Michael Pollan teaches journalism at the University of California,
Berkeley. "Cooked: A Natural History of Transformation" is his most
recent book.Read more »
More:BiologyBrainsCaffeineCharles DarwinConsciousnessEcology
A Reporter at Large
December 23 & 30, 2013 Issue
The Intelligent Plant
Scientists debate a new way of understanding flora.
By Michael Pollan
Plants have electrical and chemical signalling systems, may possess
memory, and exhibit brainy behavior in the absence of brains.
Construction by Stephen Doyle / Photograph by Grant Cornett
In 1973, a book claiming that plants were sentient beings that feel
emotions, prefer classical music to rock and roll, and can respond to
the unspoken thoughts of humans hundreds of miles away landed on the New
York Times best-seller list for nonfiction. "The Secret Life of Plants,"
by Peter Tompkins and Christopher Bird, presented a beguiling mashup of
legitimate plant science, quack experiments, and mystical nature worship
that captured the public imagination at a time when New Age thinking was
seeping into the mainstream. The most memorable passages described the
experiments of a former C.I.A. polygraph expert named Cleve Backster,
who, in 1966, on a whim, hooked up a galvanometer to the leaf of a
dracaena, a houseplant that he kept in his office. To his astonishment,
Backster found that simply by imagining the dracaena being set on fire
he could make it rouse the needle of the polygraph machine, registering
a surge of electrical activity suggesting that the plant felt stress.
"Could the plant have been reading his mind?" the authors ask. "Backster
felt like running into the street and shouting to the world, 'Plants can
think!' "
Backster and his collaborators went on to hook up polygraph machines to
dozens of plants, including lettuces, onions, oranges, and bananas. He
claimed that plants reacted to the thoughts (good or ill) of humans in
close proximity and, in the case of humans familiar to them, over a
great distance. In one experiment designed to test plant memory,
Backster found that a plant that had witnessed the murder (by stomping)
of another plant could pick out the killer from a lineup of six
suspects, registering a surge of electrical activity when the murderer
was brought before it. Backster's plants also displayed a strong
aversion to interspecies violence. Some had a stressful response when an
egg was cracked in their presence, or when live shrimp were dropped into
boiling water, an experiment that Backster wrote up for the
International Journal of Parapsychology, in 1968.
In the ensuing years, several legitimate plant scientists tried to
reproduce the "Backster effect" without success. Much of the science in
"The Secret Life of Plants" has been discredited. But the book had made
its mark on the culture. Americans began talking to their plants and
playing Mozart for them, and no doubt many still do. This might seem
harmless enough; there will probably always be a strain of romanticism
running through our thinking about plants. (Luther Burbank and George
Washington Carver both reputedly talked to, and listened to, the plants
they did such brilliant work with.) But in the view of many plant
scientists "The Secret Life of Plants" has done lasting damage to their
field. According to Daniel Chamovitz, an Israeli biologist who is the
author of the recent book "What a Plant Knows," Tompkins and Bird
"stymied important research on plant behavior as scientists became wary
of any studies that hinted at parallels between animal senses and plant
senses." Others contend that "The Secret Life of Plants" led to
"self-censorship" among researchers seeking to explore the "possible
homologies between neurobiology and phytobiology"; that is, the
possibility that plants are much more intelligent and much more like us
than most people think—capable of cognition, communication, information
processing, computation, learning, and memory.
The quotation about self-censorship appeared in a controversial 2006
article in Trends in Plant Science proposing a new field of inquiry that
the authors, perhaps somewhat recklessly, elected to call "plant
neurobiology." The six authors—among them Eric D. Brenner, an American
plant molecular biologist; Stefano Mancuso, an Italian plant
physiologist; František Baluška, a Slovak cell biologist; and Elizabeth
Van Volkenburgh, an American plant biologist—argued that the
sophisticated behaviors observed in plants cannot at present be
completely explained by familiar genetic and biochemical mechanisms.
Plants are able to sense and optimally respond to so many environmental
variables—light, water, gravity, temperature, soil structure, nutrients,
toxins, microbes, herbivores, chemical signals from other plants—that
there may exist some brainlike information-processing system to
integrate the data and coördinate a plant's behavioral response. The
authors pointed out that electrical and chemical signalling systems have
been identified in plants which are homologous to those found in the
nervous systems of animals. They also noted that neurotransmitters such
as serotonin, dopamine, and glutamate have been found in plants, though
their role remains unclear.
Hence the need for plant neurobiology, a new field "aimed at
understanding how plants perceive their circumstances and respond to
environmental input in an integrated fashion." The article argued that
plants exhibit intelligence, defined by the authors as "an intrinsic
ability to process information from both abiotic and biotic stimuli that
allows optimal decisions about future activities in a given
environment." Shortly before the article's publication, the Society for
Plant Neurobiology held its first meeting, in Florence, in 2005. A new
scientific journal, with the less tendentious title Plant Signaling &
Behavior, appeared the following year.
Depending on whom you talk to in the plant sciences today, the field of
plant neurobiology represents either a radical new paradigm in our
understanding of life or a slide back down into the murky scientific
waters last stirred up by "The Secret Life of Plants." Its proponents
believe that we must stop regarding plants as passive objects—the mute,
immobile furniture of our world—and begin to treat them as protagonists
in their own dramas, highly skilled in the ways of contending in nature.
They would challenge contemporary biology's reductive focus on cells and
genes and return our attention to the organism and its behavior in the
environment. It is only human arrogance, and the fact that the lives of
plants unfold in what amounts to a much slower dimension of time, that
keep us from appreciating their intelligence and consequent success.
Plants dominate every terrestrial environment, composing ninety-nine per
cent of the biomass on earth. By comparison, humans and all the other
animals are, in the words of one plant neurobiologist, "just traces."
[cartoon id="a16804"]
Many plant scientists have pushed back hard against the nascent field,
beginning with a tart, dismissive letter in response to the Brenner
manifesto, signed by thirty-six prominent plant scientists (Alpi et al.,
in the literature) and published in Trends in Plant Science. "We begin
by stating simply that there is no evidence for structures such as
neurons, synapses or a brain in plants," the authors wrote. No such
claim had actually been made—the manifesto had spoken only of
"homologous" structures—but the use of the word "neurobiology" in the
absence of actual neurons was apparently more than many scientists could
bear.
"Yes, plants have both short- and long-term electrical signalling, and
they use some neurotransmitter-like chemicals as chemical signals,"
Lincoln Taiz, an emeritus professor of plant physiology at U.C. Santa
Cruz and one of the signers of the Alpi letter, told me. "But the
mechanisms are quite different from those of true nervous systems." Taiz
says that the writings of the plant neurobiologists suffer from
"over-interpretation of data, teleology, anthropomorphizing,
philosophizing, and wild speculations." He is confident that eventually
the plant behaviors we can't yet account for will be explained by the
action of chemical or electrical pathways, without recourse to
"animism." Clifford Slayman, a professor of cellular and molecular
physiology at Yale, who also signed the Alpi letter (and who helped
discredit Tompkins and Bird), was even more blunt. " 'Plant
intelligence' is a foolish distraction, not a new paradigm," he wrote in
a recent e-mail. Slayman has referred to the Alpi letter as "the last
serious confrontation between the scientific community and the nuthouse
on these issues." Scientists seldom use such language when talking about
their colleagues to a journalist, but this issue generates strong
feelings, perhaps because it smudges the sharp line separating the
animal kingdom from the plant kingdom. The controversy is less about the
remarkable discoveries of recent plant science than about how to
interpret and name them: whether behaviors observed in plants which look
very much like learning, memory, decision-making, and intelligence
deserve to be called by those terms or whether those words should be
reserved exclusively for creatures with brains.
No one I spoke to in the loose, interdisciplinary group of scientists
working on plant intelligence claims that plants have telekinetic powers
or feel emotions. Nor does anyone believe that we will locate a
walnut-shaped organ somewhere in plants which processes sensory data and
directs plant behavior. More likely, in the scientists' view,
intelligence in plants resembles that exhibited in insect colonies,
where it is thought to be an emergent property of a great many mindless
individuals organized in a network. Much of the research on plant
intelligence has been inspired by the new science of networks,
distributed computing, and swarm behavior, which has demonstrated some
of the ways in which remarkably brainy behavior can emerge in the
absence of actual brains.
"If you are a plant, having a brain is not an advantage," Stefano
Mancuso points out. Mancuso is perhaps the field's most impassioned
spokesman for the plant point of view. A slight, bearded Calabrian in
his late forties, he comes across more like a humanities professor than
like a scientist. When I visited him earlier this year at the
International Laboratory of Plant Neurobiology, at the University of
Florence, he told me that his conviction that humans grossly
underestimate plants has its origins in a science-fiction story he
remembers reading as a teen-ager. A race of aliens living in a radically
sped-up dimension of time arrive on Earth and, unable to detect any
movement in humans, come to the logical conclusion that we are "inert
material" with which they may do as they please. The aliens proceed
ruthlessly to exploit us. (Mancuso subsequently wrote to say that the
story he recounted was actually a mangled recollection of an early "Star
Trek" episode called "Wink of an Eye.")
In Mancuso's view, our "fetishization" of neurons, as well as our
tendency to equate behavior with mobility, keeps us from appreciating
what plants can do. For instance, since plants can't run away and
frequently get eaten, it serves them well not to have any irreplaceable
organs. "A plant has a modular design, so it can lose up to ninety per
cent of its body without being killed," he said. "There's nothing like
that in the animal world. It creates a resilience."
Indeed, many of the most impressive capabilities of plants can be traced
to their unique existential predicament as beings rooted to the ground
and therefore unable to pick up and move when they need something or
when conditions turn unfavorable. The "sessile life style," as plant
biologists term it, calls for an extensive and nuanced understanding of
one's immediate environment, since the plant has to find everything it
needs, and has to defend itself, while remaining fixed in place. A
highly developed sensory apparatus is required to locate food and
identify threats. Plants have evolved between fifteen and twenty
distinct senses, including analogues of our five: smell and taste (they
sense and respond to chemicals in the air or on their bodies); sight
(they react differently to various wavelengths of light as well as to
shadow); touch (a vine or a root "knows" when it encounters a solid
object); and, it has been discovered, sound. In a recent experiment,
Heidi Appel, a chemical ecologist at the University of Missouri, found
that, when she played a recording of a caterpillar chomping a leaf for a
plant that hadn't been touched, the sound primed the plant's genetic
machinery to produce defense chemicals. Another experiment, done in
Mancuso's lab and not yet published, found that plant roots would seek
out a buried pipe through which water was flowing even if the exterior
of the pipe was dry, which suggested that plants somehow "hear" the
sound of flowing water.
The sensory capabilities of plant roots fascinated Charles Darwin, who
in his later years became increasingly passionate about plants; he and
his son Francis performed scores of ingenious experiments on plants.
Many involved the root, or radicle, of young plants, which the Darwins
demonstrated could sense light, moisture, gravity, pressure, and several
other environmental qualities, and then determine the optimal trajectory
for the root's growth. The last sentence of Darwin's 1880 book, "The
Power of Movement in Plants," has assumed scriptural authority for some
plant neurobiologists: "It is hardly an exaggeration to say that the tip
of the radicle . . . having the power of directing the movements of the
adjoining parts, acts like the brain of one of the lower animals; the
brain being seated within the anterior end of the body, receiving
impressions from the sense organs and directing the several movements."
Darwin was asking us to think of the plant as a kind of upside-down
animal, with its main sensory organs and "brain" on the bottom,
underground, and its sexual organs on top. [cartoon id="a17919"]
Scientists have since found that the tips of plant roots, in addition to
sensing gravity, moisture, light, pressure, and hardness, can also sense
volume, nitrogen, phosphorus, salt, various toxins, microbes, and
chemical signals from neighboring plants. Roots about to encounter an
impenetrable obstacle or a toxic substance change course before they
make contact with it. Roots can tell whether nearby roots are self or
other and, if other, kin or stranger. Normally, plants compete for root
space with strangers, but, when researchers put four closely related
Great Lakes sea-rocket plants (Cakile edentula) in the same pot, the
plants restrained their usual competitive behaviors and shared
resources.
Somehow, a plant gathers and integrates all this information about its
environment, and then "decides"—some scientists deploy the quotation
marks, indicating metaphor at work; others drop them—in precisely what
direction to deploy its roots or its leaves. Once the definition of
"behavior" expands to include such things as a shift in the trajectory
of a root, a reallocation of resources, or the emission of a powerful
chemical, plants begin to look like much more active agents, responding
to environmental cues in ways more subtle or adaptive than the word
"instinct" would suggest. "Plants perceive competitors and grow away
from them," Rick Karban, a plant ecologist at U.C. Davis, explained,
when I asked him for an example of plant decision-making. "They are more
leery of actual vegetation than they are of inanimate objects, and they
respond to potential competitors before actually being shaded by them."
These are sophisticated behaviors, but, like most plant behaviors, to an
animal they're either invisible or really, really slow.
The sessile life style also helps account for plants' extraordinary gift
for biochemistry, which far exceeds that of animals and, arguably, of
human chemists. (Many drugs, from aspirin to opiates, derive from
compounds designed by plants.) Unable to run away, plants deploy a
complex molecular vocabulary to signal distress, deter or poison
enemies, and recruit animals to perform various services for them. A
recent study in Science found that the caffeine produced by many plants
may function not only as a defense chemical, as had previously been
thought, but in some cases as a psychoactive drug in their nectar. The
caffeine encourages bees to remember a particular plant and return to
it, making them more faithful and effective pollinators.
One of the most productive areas of plant research in recent years has
been plant signalling. Since the early nineteen-eighties, it has been
known that when a plant's leaves are infected or chewed by insects they
emit volatile chemicals that signal other leaves to mount a defense.
Sometimes this warning signal contains information about the identity of
the insect, gleaned from the taste of its saliva. Depending on the plant
and the attacker, the defense might involve altering the leaf's flavor
or texture, or producing toxins or other compounds that render the
plant's flesh less digestible to herbivores. When antelopes browse
acacia trees, the leaves produce tannins that make them unappetizing and
difficult to digest. When food is scarce and acacias are overbrowsed, it
has been reported, the trees produce sufficient amounts of toxin to kill
the animals.
Perhaps the cleverest instance of plant signalling involves two insect
species, the first in the role of pest and the second as its
exterminator. Several species, including corn and lima beans, emit a
chemical distress call when attacked by caterpillars. Parasitic wasps
some distance away lock in on that scent, follow it to the afflicted
plant, and proceed to slowly destroy the caterpillars. Scientists call
these insects "plant bodyguards."
Plants speak in a chemical vocabulary we can't directly perceive or
comprehend. The first important discoveries in plant communication were
made in the lab in the nineteen-eighties, by isolating plants and their
chemical emissions in Plexiglas chambers, but Rick Karban, the U.C.
Davis ecologist, and others have set themselves the messier task of
studying how plants exchange chemical signals outdoors, in a natural
setting. Recently, I visited Karban's study plot at the University of
California's Sagehen Creek Field Station, a few miles outside Truckee.
On a sun-flooded hillside high in the Sierras, he introduced me to the
ninety-nine sagebrush plants—low, slow-growing gray-green shrubs marked
with plastic flags—that he and his colleagues have kept under close
surveillance for more than a decade.
Karban, a fifty-nine-year-old former New Yorker, is slender, with a
thatch of white curls barely contained by a floppy hat. He has shown
that when sagebrush leaves are clipped in the spring—simulating an
insect attack that triggers the release of volatile chemicals—both the
clipped plant and its unclipped neighbors suffer significantly less
insect damage over the season. Karban believes that the plant is
alerting all its leaves to the presence of a pest, but its neighbors
pick up the signal, too, and gird themselves against attack. "We think
the sagebrush are basically eavesdropping on one another," Karban said.
He found that the more closely related the plants the more likely they
are to respond to the chemical signal, suggesting that plants may
display a form of kin recognition. Helping out your relatives is a good
way to improve the odds that your genes will survive.
The field work and data collection that go into making these discoveries
are painstaking in the extreme. At the bottom of a meadow raked by the
slanted light of late summer, two collaborators from Japan, Kaori
Shiojiri and Satomi Ishizaki, worked in the shade of a small pine,
squatting over branches of sagebrush that Karban had tagged and cut.
Using clickers, they counted every trident-shaped leaf on every branch,
and then counted and recorded every instance of leaf damage, one column
for insect bites, another for disease. At the top of the meadow, another
collaborator, James Blande, a chemical ecologist from England, tied
plastic bags around sagebrush stems and inflated the bags with filtered
air. After waiting twenty minutes for the leaves to emit their
volatiles, he pumped the air through a metal cylinder containing an
absorbent material that collected the chemical emissions. At the lab, a
gas chromatograph-mass spectrometer would yield a list of the compounds
collected—more than a hundred in all. Blande offered to let me put my
nose in one of the bags; the air was powerfully aromatic, with a scent
closer to aftershave than to perfume. Gazing across the meadow of
sagebrush, I found it difficult to imagine the invisible chemical
chatter, including the calls of distress, going on all around—or that
these motionless plants were engaged in any kind of "behavior" at all.
Research on plant communication may someday benefit farmers and their
crops. Plant-distress chemicals could be used to prime plant defenses,
reducing the need for pesticides. Jack Schultz, a chemical ecologist at
the University of Missouri, who did some of the pioneering work on plant
signalling in the early nineteen-eighties, is helping to develop a
mechanical "nose" that, attached to a tractor and driven through a
field, could help farmers identify plants under insect attack, allowing
them to spray pesticides only when and where they are needed. [cartoon
id="a17864"]
Karban told me that, in the nineteen-eighties, people working on plant
communication faced some of the same outrage that scientists working on
plant intelligence (a term he cautiously accepts) do today. "This stuff
has been enormously contentious," he says, referring to the early days
of research into plant communication, work that is now generally
accepted. "It took me years to get some of these papers published.
People would literally be screaming at one another at scientific
meetings." He added, "Plant scientists in general are incredibly
conservative. We all think we want to hear novel ideas, but we don't,
not really."
I first met Karban at a scientific meeting in Vancouver last July, when
he presented a paper titled "Plant Communication and Kin Recognition in
Sagebrush." The meeting would have been the sixth gathering of the
Society for Plant Neurobiology, if not for the fact that, under pressure
from certain quarters of the scientific establishment, the group's name
had been changed four years earlier to the less provocative Society for
Plant Signaling and Behavior. The plant biologist Elizabeth Van
Volkenburgh, of the University of Washington, who was one of the
founders of the society, told me that the name had been changed after a
lively internal debate; she felt that jettisoning "neurobiology" was
probably for the best. "I was told by someone at the National Science
Foundation that the N.S.F. would never fund anything with the words
'plant neurobiology' in it. He said, and I quote, ' "Neuro" belongs to
animals.' " (An N.S.F. spokesperson said that, while the society is not
eligible for funding by the foundation's neurobiology program, "the
N.S.F. does not have a boycott of any sort against the society.") Two of
the society's co-founders, Stefano Mancuso and František Baluška, argued
strenuously against the name change, and continue to use the term "plant
neurobiology" in their own work and in the names of their labs.
The meeting consisted of three days of PowerPoint presentations
delivered in a large, modern lecture hall at the University of British
Columbia before a hundred or so scientists. Most of the papers were
highly technical presentations on plant signalling—the kind of
incremental science that takes place comfortably within the confines of
an established scientific paradigm, which plant signalling has become.
But a handful of speakers presented work very much within the new
paradigm of plant intelligence, and they elicited strong reactions.
The most controversial presentation was "Animal-Like Learning in Mimosa
Pudica," an unpublished paper by Monica Gagliano, a
thirty-seven-year-old animal ecologist at the University of Western
Australia who was working in Mancuso's lab in Florence. Gagliano, who is
tall, with long brown hair parted in the middle, based her experiment on
a set of protocols commonly used to test learning in animals. She
focussed on an elementary type of learning called "habituation," in
which an experimental subject is taught to ignore an irrelevant
stimulus. "Habituation enables an organism to focus on the important
information, while filtering out the rubbish," Gagliano explained to the
audience of plant scientists. How long does it take the animal to
recognize that a stimulus is "rubbish," and then how long will it
remember what it has learned? Gagliano's experimental question was
bracing: Could the same thing be done with a plant?
Mimosa pudica, also called the "sensitive plant," is that rare plant
species with a behavior so speedy and visible that animals can observe
it; the Venus flytrap is another. When the fernlike leaves of the mimosa
are touched, they instantly fold up, presumably to frighten insects. The
mimosa also collapses its leaves when the plant is dropped or jostled.
Gagliano potted fifty-six mimosa plants and rigged a system to drop them
from a height of fifteen centimetres every five seconds. Each "training
session" involved sixty drops. She reported that some of the mimosas
started to reopen their leaves after just four, five, or six drops, as
if they had concluded that the stimulus could be safely ignored. "By the
end, they were completely open," Gagliano said to the audience. "They
couldn't care less anymore."
Was it just fatigue? Apparently not: when the plants were shaken, they
again closed up. " 'Oh, this is something new,' " Gagliano said,
imagining these events from the plants' point of view. "You see, you
want to be attuned to something new coming in. Then we went back to the
drops, and they didn't respond." Gagliano reported that she retested her
plants after a week and found that they continued to disregard the drop
stimulus, indicating that they "remembered" what they had learned. Even
after twenty-eight days, the lesson had not been forgotten. She reminded
her colleagues that, in similar experiments with bees, the insects
forgot what they had learned after just forty-eight hours. Gagliano
concluded by suggesting that "brains and neurons are a sophisticated
solution but not a necessary requirement for learning," and that there
is "some unifying mechanism across living systems that can process
information and learn."
A lively exchange followed. Someone objected that dropping a plant was
not a relevant trigger, since that doesn't happen in nature. Gagliano
pointed out that electric shock, an equally artificial trigger, is often
used in animal-learning experiments. Another scientist suggested that
perhaps her plants were not habituated, just tuckered out. She argued
that twenty-eight days would be plenty of time to rebuild their energy
reserves.
On my way out of the lecture hall, I bumped into Fred Sack, a prominent
botanist at the University of British Columbia. I asked him what he
thought of Gagliano's presentation. "Bullshit," he replied. He explained
that the word "learning" implied a brain and should be reserved for
animals: "Animals can exhibit learning, but plants evolve adaptations."
He was making a distinction between behavioral changes that occur within
the lifetime of an organism and those which arise across generations. At
lunch, I sat with a Russian scientist, who was equally dismissive. "It's
not learning," he said. "So there's nothing to discuss." [cartoon
id="a17930"]
Later that afternoon, Gagliano seemed both stung by some of the
reactions to her presentation and defiant. Adaptation is far too slow a
process to explain the behavior she had observed, she told me. "How can
they be adapted to something they have never experienced in their real
world?" She noted that some of her plants learned faster than others,
evidence that "this is not an innate or programmed response." Many of
the scientists in her audience were just getting used to the ideas of
plant "behavior" and "memory" (terms that even Fred Sack said he was
willing to accept); using words like "learning" and "intelligence" in
plants struck them, in Sack's words, as "inappropriate" and "just
weird." When I described the experiment to Lincoln Taiz, he suggested
the words "habituation" or "desensitization" would be more appropriate
than "learning." Gagliano said that her mimosa paper had been rejected
by ten journals: "None of the reviewers had problems with the data."
Instead, they balked at the language she used to describe the data. But
she didn't want to change it. "Unless we use the same language to
describe the same behavior"—exhibited by plants and animals—"we can't
compare it," she said.
Rick Karban consoled Gagliano after her talk. "I went through the same
thing, just getting totally hammered," he told her. "But you're doing
good work. The system is just not ready." When I asked him what he
thought of Gagliano's paper, he said, "I don't know if she's got
everything nailed down, but it's a very cool idea that deserves to get
out there and be discussed. I hope she doesn't get discouraged."
Scientists are often uncomfortable talking about the role of metaphor
and imagination in their work, yet scientific progress often depends on
both. "Metaphors help stimulate the investigative imagination of good
scientists," the British plant scientist Anthony Trewavas wrote in a
spirited response to the Alpi letter denouncing plant neurobiology.
"Plant neurobiology" is obviously a metaphor—plants don't possess the
type of excitable, communicative cells we call neurons. Yet the
introduction of the term has raised a series of questions and inspired a
set of experiments that promise to deepen our understanding not only of
plants but potentially also of brains. If there are other ways of
processing information, other kinds of cells and cell networks that can
somehow give rise to intelligent behavior, then we may be more inclined
to ask, with Mancuso, "What's so special about neurons?"
Mancuso is the poet-philosopher of the movement, determined to win for
plants the recognition they deserve and, perhaps, bring humans down a
peg in the process. His somewhat grandly named International Laboratory
of Plant Neurobiology, a few miles outside Florence, occupies a modest
suite of labs and offices in a low-slung modern building. Here a handful
of collaborators and graduate students work on the experiments Mancuso
devises to test the intelligence of plants. Giving a tour of the labs,
he showed me maize plants, grown under lights, that were being taught to
ignore shadows; a poplar sapling hooked up to a galvanometer to measure
its response to air pollution; and a chamber in which a PTR-TOF
machine—an advanced kind of mass spectrometer—continuously read all the
volatiles emitted by a succession of plants, from poplars and tobacco
plants to peppers and olive trees. "We are making a dictionary of each
species' entire chemical vocabulary," he explained. He estimates that a
plant has three thousand chemicals in its vocabulary, while, he said
with a smile, "the average student has only seven hundred words."
Mancuso is fiercely devoted to plants—a scientist needs to "love" his
subject in order to do it justice, he says. He is also gentle and
unassuming, even when what he is saying is outrageous. In the corner of
his office sits a forlorn Ficus benjamina, or weeping fig, and on the
walls are photographs of Mancuso in an astronaut's jumpsuit floating in
the cabin of a zero-gravity aircraft; he has collaborated with the
European Space Agency, which has supported his research on plant
behavior in micro- and hyper-gravity. (One of his experiments was
carried on board the last flight of the space shuttle Endeavor, in May
of 2011.) A decade ago, Mancuso persuaded a Florentine bank foundation
to underwrite much of his research and help launch the Society for Plant
Neurobiology; his lab also receives grants from the European Union.
Early in our conversation, I asked Mancuso for his definition of
"intelligence." Spending so much time with the plant neurobiologists, I
could feel my grasp on the word getting less sure. It turns out that I
am not alone: philosophers and psychologists have been arguing over the
definition of intelligence for at least a century, and whatever
consensus there may once have been has been rapidly slipping away. Most
definitions of intelligence fall into one of two categories. The first
is worded so that intelligence requires a brain; the definition refers
to intrinsic mental qualities such as reason, judgment, and abstract
thought. The second category, less brain-bound and metaphysical,
stresses behavior, defining intelligence as the ability to respond in
optimal ways to the challenges presented by one's environment and
circumstances. Not surprisingly, the plant neurobiologists jump into
this second camp.
"I define it very simply," Mancuso said. "Intelligence is the ability to
solve problems." In place of a brain, "what I am looking for is a
distributed sort of intelligence, as we see in the swarming of birds."
In a flock, each bird has only to follow a few simple rules, such as
maintaining a prescribed distance from its neighbor, yet the collective
effect of a great many birds executing a simple algorithm is a complex
and supremely well-coördinated behavior. Mancuso's hypothesis is that
something similar is at work in plants, with their thousands of root
tips playing the role of the individual birds—gathering and assessing
data from the environment and responding in local but coördinated ways
that benefit the entire organism.
"Neurons perhaps are overrated," Mancuso said. "They're really just
excitable cells." Plants have their own excitable cells, many of them in
a region just behind the root tip. Here Mancuso and his frequent
collaborator, František Baluška, have detected unusually high levels of
electrical activity and oxygen consumption. They've hypothesized in a
series of papers that this so-called "transition zone" may be the locus
of the "root brain" first proposed by Darwin. The idea remains unproved
and controversial. "What's going on there is not well understood,"
Lincoln Taiz told me, "but there is no evidence it is a command center."
How plants do what they do without a brain—what Anthony Trewavas has
called their "mindless mastery"—raises questions about how our brains do
what they do. When I asked Mancuso about the function and location of
memory in plants, he speculated about the possible role of calcium
channels and other mechanisms, but then he reminded me that mystery
still surrounds where and how our memories are stored: "It could be the
same kind of machinery, and figuring it out in plants may help us figure
it out in humans." [cartoon id="a17948"]
The hypothesis that intelligent behavior in plants may be an emergent
property of cells exchanging signals in a network might sound
far-fetched, yet the way that intelligence emerges from a network of
neurons may not be very different. Most neuroscientists would agree
that, while brains considered as a whole function as centralized command
centers for most animals, within the brain there doesn't appear to be
any command post; rather, one finds a leaderless network. That sense we
get when we think about what might govern a plant—that there is no there
there, no wizard behind the curtain pulling the levers—may apply equally
well to our brains.
In Martin Amis's 1995 novel, "The Information," we meet a character who
aspires to write "The History of Increasing Humiliation," a treatise
chronicling the gradual dethronement of humankind from its position at
the center of the universe, beginning with Copernicus. "Every century we
get smaller," Amis writes. Next came Darwin, who brought the humbling
news that we are the product of the same natural laws that created
animals. In the last century, the formerly sharp lines separating humans
from animals—our monopolies on language, reason, toolmaking, culture,
even self-consciousness—have been blurred, one after another, as science
has granted these capabilities to other animals.
Mancuso and his colleagues are writing the next chapter in "The History
of Increasing Humiliation." Their project entails breaking down the
walls between the kingdoms of plants and animals, and it is proceeding
not only experiment by experiment but also word by word. Start with that
slippery word "intelligence." Particularly when there is no dominant
definition (and when measurements of intelligence, such as I.Q., have
been shown to be culturally biased), it is possible to define
intelligence in a way that either reinforces the boundary between
animals and plants (say, one that entails abstract thought) or
undermines it. Plant neurobiologists have chosen to define intelligence
democratically, as an ability to solve problems or, more precisely, to
respond adaptively to circumstances, including ones unforeseen in the
genome.
"I agree that humans are special," Mancuso says. "We are the first
species able to argue about what intelligence is. But it's the quantity,
not the quality" of intelligence that sets us apart. We exist on a
continuum with the acacia, the radish, and the bacterium. "Intelligence
is a property of life," he says. I asked him why he thinks people have
an easier time granting intelligence to computers than to plants. (Fred
Sack told me that he can abide the term "artificial intelligence,"
because the intelligence in this case is modified by the word
"artificial," but not "plant intelligence." He offered no argument,
except to say, "I'm in the majority in saying it's a little weird.")
Mancuso thinks we're willing to accept artificial intelligence because
computers are our creations, and so reflect our own intelligence back at
us. They are also our dependents, unlike plants: "If we were to vanish
tomorrow, the plants would be fine, but if the plants vanished . . ."
Our dependence on plants breeds a contempt for them, Mancuso believes.
In his somewhat topsy-turvy view, plants "remind us of our weakness."
"Memory" may be an even thornier word to apply across kingdoms, perhaps
because we know so little about how it works. We tend to think of
memories as immaterial, but in animal brains some forms of memory
involve the laying down of new connections in a network of neurons. Yet
there are ways to store information biologically that don't require
neurons. Immune cells "remember" their experience of pathogens, and call
on that memory in subsequent encounters. In plants, it has long been
known that experiences such as stress can alter the molecular wrapping
around the chromosomes; this, in turn, determines which genes will be
silenced and which expressed. This so-called "epigenetic" effect can
persist and sometimes be passed down to offspring. More recently,
scientists have found that life events such as trauma or starvation
produce epigenetic changes in animal brains (coding for high levels of
cortisol, for example) that are long-lasting and can also be passed down
to offspring, a form of memory much like that observed in plants.
While talking with Mancuso, I kept thinking about words like "will,"
"choice," and "intention," which he seemed to attribute to plants rather
casually, almost as if they were acting consciously. At one point, he
told me about the dodder vine, Cuscuta europaea, a parasitic white vine
that winds itself around the stalk of another plant and sucks
nourishment from it. A dodder vine will "choose" among several potential
hosts, assessing, by scent, which offers the best potential nourishment.
Having selected a target, the vine then performs a kind of cost-benefit
calculation before deciding exactly how many coils it should invest—the
more nutrients in the victim, the more coils it deploys. I asked Mancuso
whether he was being literal or metaphorical in attributing intention to
plants.
"Here, I'll show you something," he said. "Then you tell me if plants
have intention." He swivelled his computer monitor around and clicked
open a video.
Time-lapse photography is perhaps the best tool we have to bridge the
chasm between the time scale at which plants live and our own. This
example was of a young bean plant, shot in the lab over two days, one
frame every ten minutes. A metal pole on a dolly stands a couple of feet
away. The bean plant is "looking" for something to climb. Each spring, I
witness the same process in my garden, in real time. I always assumed
that the bean plants simply grow this way or that, until they eventually
bump into something suitable to climb. But Mancuso's video seems to show
that this bean plant "knows" exactly where the metal pole is long before
it makes contact with it. Mancuso speculates that the plant could be
employing a form of echolocation. There is some evidence that plants
make low clicking sounds as their cells elongate; it's possible that
they can sense the reflection of those sound waves bouncing off the
metal pole.
The bean plant wastes no time or energy "looking"—that is,
growing—anywhere but in the direction of the pole. And it is striving
(there is no other word for it) to get there: reaching, stretching,
throwing itself over and over like a fly rod, extending itself a few
more inches with every cast, as it attempts to wrap its curling tip
around the pole. As soon as contact is made, the plant appears to relax;
its clenched leaves begin to flutter mildly. All this may be nothing
more than an illusion of time-lapse photography. Yet to watch the video
is to feel, momentarily, like one of the aliens in Mancuso's formative
science-fiction story, shown a window onto a dimension of time in which
these formerly inert beings come astonishingly to life, seemingly
conscious individuals with intentions. [cartoon id="sipress-2011-05-16"]
In October, I loaded the bean video onto my laptop and drove down to
Santa Cruz to play it for Lincoln Taiz. He began by questioning its
value as scientific data: "Maybe he has ten other videos where the bean
didn't do that. You can't take one interesting variation and generalize
from it." The bean's behavior was, in other words, an anecdote, not a
phenomenon. Taiz also pointed out that the bean in the video was leaning
toward the pole in the first frame. Mancuso then sent me another video
with two perfectly upright bean plants that exhibited very similar
behavior. Taiz was now intrigued. "If he sees that effect consistently,
it would be exciting," he said—but it would not necessarily be evidence
of plant intention. "If the phenomenon is real, it would be classified
as a tropism," such as the mechanism that causes plants to bend toward
light. In this case, the stimulus remains unknown, but tropisms "do not
require one to postulate either intentionality or 'brainlike'
conceptualization," Taiz said. "The burden of proof for the latter
interpretation would clearly be on Stefano."
Perhaps the most troublesome and troubling word of all in thinking about
plants is "consciousness." If consciousness is defined as inward
awareness of oneself experiencing reality—"the feeling of what happens,"
in the words of the neuroscientist Antonio Damasio—then we can
(probably) safely conclude that plants don't possess it. But if we
define the term simply as the state of being awake and aware of one's
environment—"online," as the neuroscientists say—then plants may qualify
as conscious beings, at least according to Mancuso and Baluška. "The
bean knows exactly what is in the environment around it," Mancuso said.
"We don't know how. But this is one of the features of consciousness:
You know your position in the world. A stone does not."
In support of their contention that plants are conscious of their
environment, Mancuso and Baluška point out that plants can be rendered
unconscious by the same anesthetics that put animals out: drugs can
induce in plants an unresponsive state resembling sleep. (A snoozing
Venus flytrap won't notice an insect crossing its threshold.) What's
more, when plants are injured or stressed, they produce a
chemical—ethylene—that works as an anesthetic on animals. When I learned
this startling fact from Baluška in Vancouver, I asked him, gingerly, if
he meant to suggest that plants could feel pain. Baluška, who has a
gruff mien and a large bullet-shaped head, raised one eyebrow and shot
me a look that I took to mean he deemed my question impertinent or
absurd. But apparently not.
"If plants are conscious, then, yes, they should feel pain," he said.
"If you don't feel pain, you ignore danger and you don't survive. Pain
is adaptive." I must have shown some alarm. "That's a scary idea," he
acknowledged with a shrug. "We live in a world where we must eat other
organisms."
Unprepared to consider the ethical implications of plant intelligence, I
could feel my resistance to the whole idea stiffen. Descartes, who
believed that only humans possessed self-consciousness, was unable to
credit the idea that other animals could suffer from pain. So he
dismissed their screams and howls as mere reflexes, as meaningless
physiological noise. Could it be remotely possible that we are now
making the same mistake with plants? That the perfume of jasmine or
basil, or the scent of freshly mowed grass, so sweet to us, is (as the
ecologist Jack Schultz likes to say) the chemical equivalent of a
scream? Or have we, merely by posing such a question, fallen back into
the muddied waters of "The Secret Life of Plants"?
Lincoln Taiz has little patience for the notion of plant pain,
questioning what, in the absence of a brain, would be doing the feeling.
He puts it succinctly: "No brain, no pain." Mancuso is more circumspect.
We can never determine with certainty whether plants feel pain or
whether their perception of injury is sufficiently like that of animals
to be called by the same word. (He and Baluška are careful to write of
"plant-specific pain perception.") "We just don't know, so we must be
silent."
Mancuso believes that, because plants are sensitive and intelligent
beings, we are obliged to treat them with some degree of respect. That
means protecting their habitats from destruction and avoiding practices
such as genetic manipulation, growing plants in monocultures, and
training them in bonsai. But it does not prevent us from eating them.
"Plants evolved to be eaten—it is part of their evolutionary strategy,"
he said. He cited their modular structure and lack of irreplaceable
organs in support of this view.
The central issue dividing the plant neurobiologists from their critics
would appear to be this: Do capabilities such as intelligence, pain
perception, learning, and memory require the existence of a brain, as
the critics contend, or can they be detached from their neurobiological
moorings? The question is as much philosophical as it is scientific,
since the answer depends on how these terms get defined. The proponents
of plant intelligence argue that the traditional definitions of these
terms are anthropocentric—a clever reply to the charges of
anthropomorphism frequently thrown at them. Their attempt to broaden
these definitions is made easier by the fact that the meanings of so
many of these terms are up for grabs. At the same time, since these
words were originally created to describe animal attributes, we
shouldn't be surprised at the awkward fit with plants. It seems likely
that, if the plant neurobiologists were willing to add the prefix
"plant-specific" to intelligence and learning and memory and
consciousness (as Mancuso and Baluška are prepared to do in the case of
pain), then at least some of this "scientific controversy" might
evaporate.
Indeed, I found more consensus on the underlying science than I
expected. Even Clifford Slayman, the Yale biologist who signed the 2007
letter dismissing plant neurobiology, is willing to acknowledge that,
although he doesn't think plants possess intelligence, he does believe
they are capable of "intelligent behavior," in the same way that bees
and ants are. In an e-mail exchange, Slayman made a point of underlining
this distinction: "We do not know what constitutes intelligence, only
what we can observe and judge as intelligent behavior." He defined
"intelligent behavior" as "the ability to adapt to changing
circumstances" and noted that it "must always be measured relative to a
particular environment." Humans may or may not be intrinsically more
intelligent than cats, he wrote, but when a cat is confronted with a
mouse its behavior is likely to be demonstrably more intelligent.
[cartoon id="stevens-2011-05-23"]
Slayman went on to acknowledge that "intelligent behavior could
perfectly well develop without such a nerve center or headquarters or
director or brain—whatever you want to call it. Instead of 'brain,'
think 'network.' It seems to be that many higher organisms are
internally networked in such a way that local changes," such as the way
that roots respond to a water gradient, "cause very local responses
which benefit the entire organism." Seen that way, he added, the outlook
of Mancuso and Trewavas is "pretty much in line with my understanding of
biochemical/biological networks." He pointed out that while it is an
understandable human prejudice to favor the "nerve center" model, we
also have a second, autonomic nervous system governing our digestive
processes, which "operates most of the time without instructions from
higher up." Brains are just one of nature's ways of getting complex jobs
done, for dealing intelligently with the challenges presented by the
environment. But they are not the only way: "Yes, I would argue that
intelligent behavior is a property of life."
To define certain words in such a way as to bring plants and animals
beneath the same semantic umbrella—whether of intelligence or intention
or learning—is a philosophical choice with important consequences for
how we see ourselves in nature. Since "The Origin of Species," we have
understood, at least intellectually, the continuities among life's
kingdoms—that we are all cut from the same fabric of nature. Yet our big
brains, and perhaps our experience of inwardness, allow us to feel that
we must be fundamentally different—suspended above nature and other
species as if by some metaphysical "skyhook," to borrow a phrase from
the philosopher Daniel Dennett. Plant neurobiologists are intent on
taking away our skyhook, completing the revolution that Darwin started
but which remains—psychologically, at least—incomplete.
"What we learned from Darwin is that competence precedes comprehension,"
Dennett said when I called to talk to him about plant neurobiology. Upon
a foundation of the simplest competences—such as the on-off switch in a
computer, or the electrical and chemical signalling of a cell—can be
built higher and higher competences until you wind up with something
that looks very much like intelligence. "The idea that there is a bright
line, with real comprehension and real minds on the far side of the
chasm, and animals or plants on the other—that's an archaic myth." To
say that higher competences such as intelligence, learning, and memory
"mean nothing in the absence of brains" is, in Dennett's view,
"cerebrocentric."
All species face the same existential challenges—obtaining food,
defending themselves, reproducing—but under wildly varying
circumstances, and so they have evolved wildly different tools in order
to survive. Brains come in handy for creatures that move around a lot;
but they're a disadvantage for ones that are rooted in place. Impressive
as it is to us, self-consciousness is just another tool for living, good
for some jobs, unhelpful for others. That humans would rate this
particular adaptation so highly is not surprising, since it has been the
shining destination of our long evolutionary journey, along with the
epiphenomenon of self-consciousness that we call "free will."
In addition to being a plant physiologist, Lincoln Taiz writes about the
history of science. "Starting with Darwin's grandfather, Erasmus," he
told me, "there has been a strain of teleology in the study of plant
biology"—a habit of ascribing purpose or intention to the behavior of
plants. I asked Taiz about the question of "choice," or decision-making,
in plants, as when they must decide between two conflicting
environmental signals—water and gravity, for example.
"Does the plant decide in the same way that we choose at a deli between
a Reuben sandwich or lox and bagel?" Taiz asked. "No, the plant response
is based entirely on the net flow of auxin and other chemical signals.
The verb 'decide' is inappropriate in a plant context. It implies free
will. Of course, one could argue that humans lack free will too, but
that is a separate issue."
I asked Mancuso if he thought that a plant decides in the same way we
might choose at a deli between a Reuben or lox and bagels.
"Yes, in the same way," Mancuso wrote back, though he indicated that he
had no idea what a Reuben was. "Just put ammonium nitrate in the place
of Reuben sandwich (whatever it is) and phosphate instead of salmon, and
the roots will make a decision." But isn't the root responding simply to
the net flow of certain chemicals? "I'm afraid our brain makes decisions
in the same exact way."
"Why would a plant care about Mozart?" the late ethnobotanist Tim
Plowman would reply when asked about the wonders catalogued in "The
Secret Life of Plants." "And even if it did, why should that impress us?
They can eat light, isn't that enough?"
One way to exalt plants is by demonstrating their animal-like
capabilities. But another way is to focus on all the things plants can
do that we cannot. Some scientists working on plant intelligence have
questioned whether the "animal-centric" emphasis, along with the
obsession with the term "neurobiology," has been a mistake and possibly
an insult to the plants. "I have no interest in making plants into
little animals," one scientist wrote during the dustup over what to call
the society. "Plants are unique," another wrote. "There is no reason to
. . . call them demi-animals."
When I met Mancuso for dinner during the conference in Vancouver, he
sounded very much like a plant scientist getting over a case of "brain
envy"—what Taiz had suggested was motivating the plant neurologists. If
we could begin to understand plants on their own terms, he said, "it
would be like being in contact with an alien culture. But we could have
all the advantages of that contact without any of the problems—because
it doesn't want to destroy us!" How do plants do all the amazing things
they do without brains? Without locomotion? By focussing on the
otherness of plants rather than on their likeness, Mancuso suggested, we
stand to learn valuable things and develop important new technologies.
This was to be the theme of his presentation to the conference, the
following morning, on what he called "bioinspiration." How might the
example of plant intelligence help us design better computers, or
robots, or networks?
Mancuso was about to begin a collaboration with a prominent computer
scientist to design a plant-based computer, modelled on the distributed
computing performed by thousands of roots processing a vast number of
environmental variables. His collaborator, Andrew Adamatzky, the
director of the International Center of Unconventional Computing, at the
University of the West of England, has worked extensively with slime
molds, harnessing their maze-navigating and computational abilities.
(Adamatzky's slime molds, which are a kind of amoeba, grow in the
direction of multiple food sources simultaneously, usually oat flakes,
in the process computing and remembering the shortest distance between
any two of them; he has used these organisms to model transportation
networks.) In an e-mail, Adamatzky said that, as a substrate for
biological computing, plants offered both advantages and disadvantages
over slime molds. "Plants are more robust," he wrote, and "can keep
their shape for a very long time," although they are slower-growing and
lack the flexibility of slime molds. But because plants are already
"analog electrical computers," trafficking in electrical inputs and
outputs, he is hopeful that he and Mancuso will be able to harness them
for computational tasks. [cartoon id="vey-2011-04-18"]
Mancuso was also working with Barbara Mazzolai, a
biologist-turned-engineer at the Italian Institute of Technology, in
Genoa, to design what he called a "plantoid": a robot designed on plant
principles. "If you look at the history of robots, they are always based
on animals—they are humanoids or insectoids. If you want something
swimming, you look at a fish. But what about imitating plants instead?
What would that allow you to do? Explore the soil!" With a grant from
the European Union's Future and Emerging Technologies program, their
team is developing a "robotic root" that, using plastics that can
elongate and then harden, will be able to slowly penetrate the soil,
sense conditions, and alter its trajectory accordingly. "If you want to
explore other planets, the best thing is to send plantoids."
The most bracing part of Mancuso's talk on bioinspiration came when he
discussed underground plant networks. Citing the research of Suzanne
Simard, a forest ecologist at the University of British Columbia, and
her colleagues, Mancuso showed a slide depicting how trees in a forest
organize themselves into far-flung networks, using the underground web
of mycorrhizal fungi which connects their roots to exchange information
and even goods. This "wood-wide web," as the title of one paper put it,
allows scores of trees in a forest to convey warnings of insect attacks,
and also to deliver carbon, nitrogen, and water to trees in need.
When I reached Simard by phone, she described how she and her colleagues
track the flow of nutrients and chemical signals through this invisible
underground network. They injected fir trees with radioactive carbon
isotopes, then followed the spread of the isotopes through the forest
community using a variety of sensing methods, including a Geiger
counter. Within a few days, stores of radioactive carbon had been routed
from tree to tree. Every tree in a plot thirty metres square was
connected to the network; the oldest trees functioned as hubs, some with
as many as forty-seven connections. The diagram of the forest network
resembled an airline route map.
The pattern of nutrient traffic showed how "mother trees" were using the
network to nourish shaded seedlings, including their offspring—which the
trees can apparently recognize as kin—until they're tall enough to reach
the light. And, in a striking example of interspecies coöperation,
Simard found that fir trees were using the fungal web to trade nutrients
with paper-bark birch trees over the course of the season. The evergreen
species will tide over the deciduous one when it has sugars to spare,
and then call in the debt later in the season. For the forest community,
the value of this coöperative underground economy appears to be better
over-all health, more total photosynthesis, and greater resilience in
the face of disturbance.
In his talk, Mancuso juxtaposed a slide of the nodes and links in one of
these subterranean forest networks with a diagram of the Internet, and
suggested that in some respects the former was superior. "Plants are
able to create scalable networks of self-maintaining, self-operating,
and self-repairing units," he said. "Plants."
As I listened to Mancuso limn the marvels unfolding beneath our feet, it
occurred to me that plants do have a secret life, and it is even
stranger and more wonderful than the one described by Tompkins and Bird.
When most of us think of plants, to the extent that we think about
plants at all, we think of them as old—holdovers from a simpler,
prehuman evolutionary past. But for Mancuso plants hold the key to a
future that will be organized around systems and technologies that are
networked, decentralized, modular, reiterated, redundant—and green, able
to nourish themselves on light. "Plants are the great symbol of
modernity." Or should be: their brainlessness turns out to be their
strength, and perhaps the most valuable inspiration we can take from
them.
At dinner in Vancouver, Mancuso said, "Since you visited me in Florence,
I came across this sentence of Karl Marx, and I became obsessed with it:
'Everything that is solid melts into air.' Whenever we build anything,
it is inspired by the architecture of our bodies. So it will have a
solid structure and a center, but that is inherently fragile. This is
the meaning of that sentence—'Everything solid melts into air.' So
that's the question: Can we now imagine something completely different,
something inspired instead by plants?" ♦
Michael Pollan teaches journalism at the University of California,
Berkeley. "Cooked: A Natural History of Transformation" is his most
recent book.Read more »
More:BiologyBrainsCaffeineCharles DarwinConsciousnessEcology
Sunday, July 30, 2017
plant diversity
http://www.thehindu.com/sci-tech/science/jd-hooker-indian-plants-and-the-unexplored-himalayas/article19385251.ece
J.D. Hooker, Indian plants and the unexplored Himalayas
Kamal Bawa, R. Ganesan
July 29, 2017 17:14 IST
Updated: July 29, 2017 17:18 IST
Diversity: In present-day India alone, the genus Impatiens, for example,
is known to contain more than twice the 100 or so species estimated by
Hooker.
We should pause and reflect on the current status of the documentation
of India's amazing plant wealth
Sir Joseph Dalton Hooker, one of the greatest explorers of the
nineteenth century, and the closest friend of Charles Darwin, was 32
years old when, in 1849, he visited the then remote kingdom of Sikkim in
the Eastern Himalaya. Over a two-year period, he travelled widely in the
Darjeeling-Sikkim Himalaya and described over 3,000 species of plants
for the tiny state of Sikkim, 7,096 square kilometre in size.
After Hooker returned to England he went on to write, over a 25-year
period, the seven-volume Flora of the British India—the first and still
the only authoritative account of the plants of the vast sub-continent.
June 30, this year, marked Hooker's 200th birth anniversary.
While celebrating the bicentenary of Hooker's birth and his enormous
contribution to the documentation of biodiversity in one of the hottest
global hotspots of biodiversity, we should pause and reflect on the
current status of the documentation of India's amazing plant wealth, the
pace of global environmental change that is impacting this plant wealth,
and the prospects for sustainability in the Himalaya, particularly the
Eastern Himalaya, where Hooker conducted his most notable studies that
led to the compilation of the flora of a vast region.
It is questionable if the pace of cataloguing life in India or South
Asia has advanced very much since Hooker's time. The descriptions of
many plant genera on which Hooker worked still remain incomplete.
Hooker, for example, wrote to Charles Darwin about the taxonomic status
of Impatiens: "I took down the most difficult genus of Indian plants I
could think of to work at:—viz. Impatiens of which there are just 100
Indian species! I have made the first draft of a monograph of them…"
(J.D. Hooker to Charles Darwin, December 2, 1857:
https://cudl.lib.cam.ac.uk/view/MS-DAR-00104-00178/3). Since the
pioneering work of Hooker, species of Impatiens from the entire Himalaya
or India have not been fully catalogued.
Hooker's exploration of the Indian sub-continent was very limited. He
could visit only a small part of the huge sub-continent. In present-day
India alone, the genus Impatiens, for example, is now known to contain
more than twice the 100 or so species estimated by Hooker: the British
India at the time of Hooker included Pakistan, Bangladesh and Myanmar.
New species of Impatiens from the Himalaya are being described every now
and then. Thus, further work is necessary to fully document India's
incredible diversity of plants, especially from the unexplored regions
of the Eastern Himalaya.
Stupendous effort
It is interesting that Hooker single-handedly organised the effort to
write the flora of a sub-continent, extraordinarily rich in species.
British India at Hooker's time perhaps had more than 25,000 species of
flowering plants. Hooker described about 16,000 of these species. With
modern digital and other tools, and a sound infrastructure for field
work that Hooker could not dream of, Indian scientists have a great
opportunity to complete Hooker's unfinished task, and to produce a
complete, modern authenticated list of India's plants.
The neglect of plant exploration in India, particularly in the Eastern
Himalaya, where Hooker began his professional career, is ironic. The
Eastern Himalaya, along with Hengduan Mountains, matches the Andes that
include the lowlands of South America, as among the world's richest
centres of plant diversity. There are thousands of economically
important species, many such as rhododendrons, orchids, poppies,
primroses and, of course, Hooker's balsams (Impatiens) of immense
horticultural significance. Many species remain to be discovered:
despite the lack of systematic exploration, from 1998 to 2014, according
to the World Wildlife Fund, India, 375 species of new plants were
discovered in the Indian part of the Eastern Himalaya.
Changing landscape
At the same time, the Himalaya is changing rapidly. When Hooker visited
Darjeeling and Sikkim, he writes in his Himalayan Journals that he could
see dense forests all around him. These forests now exist as a patchwork
of fragments, and are threatened by a host of factors such as expanding
populations, infrastructure development (roads and hydropower) and
climate change.
There is thus an urgent need to conserve remaining biodiversity and the
associated ecosystem services, particularly in the light of a recent
report about the world wide "annihilation" of the biological world, also
termed as the sixth mass extinction. Our country, for instance, has lost
more than 50% of the populations of many of our large mammals.
This decimation of life is particularly ironic when many species are yet
to be discovered, and when the evidence is mounting that nature provides
us with a host of economic benefits that we had not thought of before.
Take for example a recent, widely publicised, study that shows that
economic flows from six selected tiger reserves range from US$128
million to US$271 million per year.
A commitment to fully document the richness and the value of life in the
Himalaya for the benefit of our society might be the best way to
celebrate the birth anniversary of one of the greatest plant explorers
of the world.
Kamal Bawa is Distinguished Professor of Biology at the University of
Massachusetts, Boston and the President of the Bengaluru-based Ashoka
Trust for Research in Ecology and the Environment (ATREE). R Ganesan is
a Fellow at ATREE. The views expressed are their own.
J.D. Hooker, Indian plants and the unexplored Himalayas
Kamal Bawa, R. Ganesan
July 29, 2017 17:14 IST
Updated: July 29, 2017 17:18 IST
Diversity: In present-day India alone, the genus Impatiens, for example,
is known to contain more than twice the 100 or so species estimated by
Hooker.
We should pause and reflect on the current status of the documentation
of India's amazing plant wealth
Sir Joseph Dalton Hooker, one of the greatest explorers of the
nineteenth century, and the closest friend of Charles Darwin, was 32
years old when, in 1849, he visited the then remote kingdom of Sikkim in
the Eastern Himalaya. Over a two-year period, he travelled widely in the
Darjeeling-Sikkim Himalaya and described over 3,000 species of plants
for the tiny state of Sikkim, 7,096 square kilometre in size.
After Hooker returned to England he went on to write, over a 25-year
period, the seven-volume Flora of the British India—the first and still
the only authoritative account of the plants of the vast sub-continent.
June 30, this year, marked Hooker's 200th birth anniversary.
While celebrating the bicentenary of Hooker's birth and his enormous
contribution to the documentation of biodiversity in one of the hottest
global hotspots of biodiversity, we should pause and reflect on the
current status of the documentation of India's amazing plant wealth, the
pace of global environmental change that is impacting this plant wealth,
and the prospects for sustainability in the Himalaya, particularly the
Eastern Himalaya, where Hooker conducted his most notable studies that
led to the compilation of the flora of a vast region.
It is questionable if the pace of cataloguing life in India or South
Asia has advanced very much since Hooker's time. The descriptions of
many plant genera on which Hooker worked still remain incomplete.
Hooker, for example, wrote to Charles Darwin about the taxonomic status
of Impatiens: "I took down the most difficult genus of Indian plants I
could think of to work at:—viz. Impatiens of which there are just 100
Indian species! I have made the first draft of a monograph of them…"
(J.D. Hooker to Charles Darwin, December 2, 1857:
https://cudl.lib.cam.ac.uk/view/MS-DAR-00104-00178/3). Since the
pioneering work of Hooker, species of Impatiens from the entire Himalaya
or India have not been fully catalogued.
Hooker's exploration of the Indian sub-continent was very limited. He
could visit only a small part of the huge sub-continent. In present-day
India alone, the genus Impatiens, for example, is now known to contain
more than twice the 100 or so species estimated by Hooker: the British
India at the time of Hooker included Pakistan, Bangladesh and Myanmar.
New species of Impatiens from the Himalaya are being described every now
and then. Thus, further work is necessary to fully document India's
incredible diversity of plants, especially from the unexplored regions
of the Eastern Himalaya.
Stupendous effort
It is interesting that Hooker single-handedly organised the effort to
write the flora of a sub-continent, extraordinarily rich in species.
British India at Hooker's time perhaps had more than 25,000 species of
flowering plants. Hooker described about 16,000 of these species. With
modern digital and other tools, and a sound infrastructure for field
work that Hooker could not dream of, Indian scientists have a great
opportunity to complete Hooker's unfinished task, and to produce a
complete, modern authenticated list of India's plants.
The neglect of plant exploration in India, particularly in the Eastern
Himalaya, where Hooker began his professional career, is ironic. The
Eastern Himalaya, along with Hengduan Mountains, matches the Andes that
include the lowlands of South America, as among the world's richest
centres of plant diversity. There are thousands of economically
important species, many such as rhododendrons, orchids, poppies,
primroses and, of course, Hooker's balsams (Impatiens) of immense
horticultural significance. Many species remain to be discovered:
despite the lack of systematic exploration, from 1998 to 2014, according
to the World Wildlife Fund, India, 375 species of new plants were
discovered in the Indian part of the Eastern Himalaya.
Changing landscape
At the same time, the Himalaya is changing rapidly. When Hooker visited
Darjeeling and Sikkim, he writes in his Himalayan Journals that he could
see dense forests all around him. These forests now exist as a patchwork
of fragments, and are threatened by a host of factors such as expanding
populations, infrastructure development (roads and hydropower) and
climate change.
There is thus an urgent need to conserve remaining biodiversity and the
associated ecosystem services, particularly in the light of a recent
report about the world wide "annihilation" of the biological world, also
termed as the sixth mass extinction. Our country, for instance, has lost
more than 50% of the populations of many of our large mammals.
This decimation of life is particularly ironic when many species are yet
to be discovered, and when the evidence is mounting that nature provides
us with a host of economic benefits that we had not thought of before.
Take for example a recent, widely publicised, study that shows that
economic flows from six selected tiger reserves range from US$128
million to US$271 million per year.
A commitment to fully document the richness and the value of life in the
Himalaya for the benefit of our society might be the best way to
celebrate the birth anniversary of one of the greatest plant explorers
of the world.
Kamal Bawa is Distinguished Professor of Biology at the University of
Massachusetts, Boston and the President of the Bengaluru-based Ashoka
Trust for Research in Ecology and the Environment (ATREE). R Ganesan is
a Fellow at ATREE. The views expressed are their own.
Tuesday, July 11, 2017
Aashaad kaa ek din
NASA on Friday tweeted a picture of the full moon mentioning Guru
Purnima, which is celebrated during the full moon day in the month of
Ashadh. It's known as the birthday of Veda Vyasa, and is dedicated to
teachers to pay respect and show gratitude to them.
NASA, however, did not stick to Guru Purnima alone, but tweeted about
its many other names from different traditions, including their
'favourite' — Thunder Moon.
Full moon this weekend - called Guru Purnima, Hay Moon, Mead Moon,
Ripe Corn Moon, Buck Moon, or our favorite, THUNDER MOON
pic.twitter.com/XLufAdoDEQ
— NASA Moon (@NASAmoon) July 7, 2017
Thunder Moon because thunder storms are frequent at this time of the
year.
Here's how the Moon gets the other names:
The name Hay Moon comes from harvest season as farmers bale hay for
coming winter in parts of the world.
It's also the month when Native Americans harvest corn and so it's also
called Ripe Corn Moon.
Also called Buck Moon or Full Buck Moon among the Native Americans as
this is the time male deer grow antlers.
This is when the large beehives are formed and the fermented honey is
used to produce a type of wine called Mead and that's how the full moon
gets it name of Mead Moon.
Also called #DayaxNaylaQaad in #Somali#FullMoon
— A A M Samatar (@AliMohamoud) July 7, 2017
Purnima, which is celebrated during the full moon day in the month of
Ashadh. It's known as the birthday of Veda Vyasa, and is dedicated to
teachers to pay respect and show gratitude to them.
NASA, however, did not stick to Guru Purnima alone, but tweeted about
its many other names from different traditions, including their
'favourite' — Thunder Moon.
Full moon this weekend - called Guru Purnima, Hay Moon, Mead Moon,
Ripe Corn Moon, Buck Moon, or our favorite, THUNDER MOON
pic.twitter.com/XLufAdoDEQ
— NASA Moon (@NASAmoon) July 7, 2017
Thunder Moon because thunder storms are frequent at this time of the
year.
Here's how the Moon gets the other names:
The name Hay Moon comes from harvest season as farmers bale hay for
coming winter in parts of the world.
It's also the month when Native Americans harvest corn and so it's also
called Ripe Corn Moon.
Also called Buck Moon or Full Buck Moon among the Native Americans as
this is the time male deer grow antlers.
This is when the large beehives are formed and the fermented honey is
used to produce a type of wine called Mead and that's how the full moon
gets it name of Mead Moon.
Also called #DayaxNaylaQaad in #Somali#FullMoon
— A A M Samatar (@AliMohamoud) July 7, 2017
Friday, May 19, 2017
Tuesday, March 21, 2017
book list
Math for fun
- Fantasia Mathematica : being a set of stories together with a group of
oddments...
compiled and edited by clifton fadiman
- Imaginary numbers : an anthology of marvelous mathematical stories etc
edited by William Frucht
- The Mathematical Magpie : Being More Stories...
Assembled and Edited, by Clifton Fadiman
- Sets functions and logic
- history of geometry
- joy of math
- mathematical thinking - problem-solving and proofs by John P D'angelo
and Douglas West
Computer science
- A coffeehouse conversation on the turing test
by Douglas Hofstaedter
- Metamagical Themas by Hoftaedter Douglas
- Church of the 4th dimension
- cartoon guide to CS
- the algorithmic beauty of plants - springer verlag
Child Development
- Building self-esteem in children HQ 769
- Becoming a person HQ 767.9
- The magic of Matsumoto ; the suzuki method of education MT1 Suz
- 365 things to do with your child Bill Adler Jr
- The wise child Choquette, Sonia
Marriage etc
- Understanding marriage : developments in the study of
couple interaction
- What predicts divorce ?
Languages :
- Learn Malay: A Phrase a Day - Malay-English by G. Soosai (1995-11-30)
Paperback – 1857
- The additional Michael Frayn
- Michael Erard - Verbal blunders
- The world's writing system ed by Peter Daniels and William Bright
- tamizh - bharatiyin ariviyal paarvai
Art and drawing
- The art of caricature Dick Gautier
- Great cartoonists and their art - artwood ?
- Animals that govern us Jean Malatier (or Mulatier)
Architecturea
- The Indian courtyard house by T.S> Randhawa
General Human Interest
- Matthew Stewart : The courtier and the heretic :
Leibniz, Spinoza and the fate of God in the modern world
- Calpern : Thought and Knowledge
Fiction (?)
- The wolves of willoughby chase by Joan Aiken
- I was a rat by Philip Pullman
Science books for gen reading
- Fun with optics
- Joseph Schwarz (many)
- Triplet Genetic code - Lynn E H Trainor
- Molecules : a v short intro by Philip Ball
- Braving the elements
- The joy of chemistry : the amazing science of familiar things
- The chemical adventures of sherlock holmes
- curt suplee ??
History archive
A century of news from the archives of the IHT
Film archive : Clearinghouse of south asian non-fiction filem
www.himalassociation.org/fsa/clearing.html
fsa@himalaassociation.org
Vintage
- From Plato to Bradbury : tour of some of the world's best books
Robert Kanigel
- Flatlands by Edwin Abbott
Chemistry
- Chemistry and chemical reactivity Kot 2009
- Basic concepts of chem Leo J Malone
- General chemical priciples and modern applications Ralph Petxxx
- Intro to General, organic and bio chemistry Karen timberlake
Math texts
- 101+great ideas for introducing key math concepts for sec schools
- PHB practical handbook of curve design and gneration David von seggern
- Trigonometry by Michael sullivan
- Trigonometry by cynthia young
- contemporary math in context a unified approach
- trigonometric delights by Maor Eli
- Fantasia Mathematica : being a set of stories together with a group of
oddments...
compiled and edited by clifton fadiman
- Imaginary numbers : an anthology of marvelous mathematical stories etc
edited by William Frucht
- The Mathematical Magpie : Being More Stories...
Assembled and Edited, by Clifton Fadiman
- Sets functions and logic
- history of geometry
- joy of math
- mathematical thinking - problem-solving and proofs by John P D'angelo
and Douglas West
Computer science
- A coffeehouse conversation on the turing test
by Douglas Hofstaedter
- Metamagical Themas by Hoftaedter Douglas
- Church of the 4th dimension
- cartoon guide to CS
- the algorithmic beauty of plants - springer verlag
Child Development
- Building self-esteem in children HQ 769
- Becoming a person HQ 767.9
- The magic of Matsumoto ; the suzuki method of education MT1 Suz
- 365 things to do with your child Bill Adler Jr
- The wise child Choquette, Sonia
Marriage etc
- Understanding marriage : developments in the study of
couple interaction
- What predicts divorce ?
Languages :
- Learn Malay: A Phrase a Day - Malay-English by G. Soosai (1995-11-30)
Paperback – 1857
- The additional Michael Frayn
- Michael Erard - Verbal blunders
- The world's writing system ed by Peter Daniels and William Bright
- tamizh - bharatiyin ariviyal paarvai
Art and drawing
- The art of caricature Dick Gautier
- Great cartoonists and their art - artwood ?
- Animals that govern us Jean Malatier (or Mulatier)
Architecturea
- The Indian courtyard house by T.S> Randhawa
General Human Interest
- Matthew Stewart : The courtier and the heretic :
Leibniz, Spinoza and the fate of God in the modern world
- Calpern : Thought and Knowledge
Fiction (?)
- The wolves of willoughby chase by Joan Aiken
- I was a rat by Philip Pullman
Science books for gen reading
- Fun with optics
- Joseph Schwarz (many)
- Triplet Genetic code - Lynn E H Trainor
- Molecules : a v short intro by Philip Ball
- Braving the elements
- The joy of chemistry : the amazing science of familiar things
- The chemical adventures of sherlock holmes
- curt suplee ??
History archive
A century of news from the archives of the IHT
Film archive : Clearinghouse of south asian non-fiction filem
www.himalassociation.org/fsa/clearing.html
fsa@himalaassociation.org
Vintage
- From Plato to Bradbury : tour of some of the world's best books
Robert Kanigel
- Flatlands by Edwin Abbott
Chemistry
- Chemistry and chemical reactivity Kot 2009
- Basic concepts of chem Leo J Malone
- General chemical priciples and modern applications Ralph Petxxx
- Intro to General, organic and bio chemistry Karen timberlake
Math texts
- 101+great ideas for introducing key math concepts for sec schools
- PHB practical handbook of curve design and gneration David von seggern
- Trigonometry by Michael sullivan
- Trigonometry by cynthia young
- contemporary math in context a unified approach
- trigonometric delights by Maor Eli
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