Noodling for Plant Intelligence
An Animal Rights Article from All-Creatures.org

FROM

James McWilliams
April 2014

Recently, Michael Pollan—it’s always Pollan!—wrote a New Yorker piece in which he took seriously “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 implication through it all was that plants have mental lives akin to animals. Thanks to Sacks for burying this mystical, pseudo-scientific suggestion in the same grave with rotting companions such as phrenology, eugenics, and the flying spaghetti monster.

Oliver Sacks has an important article out in the most recent New York Review of Books. In it, he explores the extensive literature—contemporary and historical—on the mental lives of plants and animals. The gist of his piece is that the plant and animal kingdoms, despite similarities on the cellular level, “evolved along two profoundly different paths.” This divergence culminated in “wholly different . . . modes of life.” The central implication of this divergence is that only animals ”learn, profit by experience, judge, act, and finally think.” Plants, in other words, are not intelligent—at least not in the way that would warrant our consideration of them as individual subjects with moral standing.

It’s worth delving a little deeper into the issue to grasp the bio-mechanical basis of this distinction. Sacks writes, “Plants depend largely on calcium ion channels, which suit their relatively slow lives perfectly. As Daniel Chamovitz argues in his book What a Plant Knows (2012), plants are capable of registering what we would call sights, sounds, tactile signals, and much more. Plants know what to do, and they ‘remember.’”

But don’t start caressing your rhododendrons just yet. As the piece’s most important paragraph explains: “The calcium ion channels that plants rely on do not support rapid or repetitive signaling between cells; once a plant action potential is generated, it cannot be repeated at a fast enough rate to allow, for example, the speed with which a worm ‘dashes…into its burrow.’ Speed requires ions and ion channels that can open and close in a matter of milliseconds, allowing hundreds of action potentials to be generated in a second. The magic ions, here, are sodium and potassium ions, which enabled the development of rapidly reacting muscle cells, nerve cells, and neuromodulation at synapses. These made possible organisms that could learn, profit by experience, judge, act, and finally think.”

In other words, they made animals possible. And, as Sacks’ worm reference suggests, the mental lives of these creatures happen to be far more complicated than many of us ever imagined. Having dismissed the notion that plants and animals share mental real estate, Sacks offers an elegant overview of the hidden state of being among murky animals ranging from insects to jellyfish to amoeba to cuttlefish. My favorite quote: “But if one allows that a dog may have consciousness of an individual and significant sort, one has to allow it for an octopus, too.” Go octopus.

If the information presented here undergirds the obvious, recall the rearguard efforts by writers of a certain persuasion who cherry-pick the evolutionary past to suggest that “plant intelligence” justifies the “humane” consumption of animals. Recently, Michael Pollan—it’s always Pollan!—wrote a New Yorker piece in which he took seriously “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 implication through it all was that plants have mental lives akin to animals. Thanks to Sacks for burying this mystical, pseudo-scientific suggestion in the same grave with rotting companions such as phrenology, eugenics, and the flying spaghetti monster. 


For more, read What About Plants? Don't Plants Have Feelings Too?

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