Noodling for Plant Intelligence

» April 5th, 2014

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.

24 Responses to Noodling for Plant Intelligence

  1. Anne Clarke says:

    It would be hard to find or even imagine a person capable of the bad faith that Pollen evinces. He has made a career out of writing what the lazy and self-indulgent US intelligentsia wants to believe about itself.

  2. Taylor says:

    Here are a couple of articles, the second probably more accessible than the first to the average reader. Both conclude that there’s a fundamental difference between plants and animals.

    Do plants have brains?
    http://www.naturalhistorymag.com/features/062208/do-plants-have-brains

    Plants cannot “think and remember,” but there’s nothing stupid about them
    http://blogs.scientificamerican.com/observations/2010/07/16/plants-cannot-think-and-remember-but-theres-nothing-stupid-about-them-theyre-shockingly-sophisticated/

  3. Mountain says:

    James, re-read Sacks’ article (and don’t forget the footnotes). He agrees with Pollan that plants are capable of “communication, information processing, computation, learning, and memory.”

    If it’s a burial you’re looking for, I think you’ll need to look elsewhere.

    • Mountain says:

      Also, pap is vegan. It’s strange that you would employ that term as an insult.

      • James says:

        Well, vegamite is vegan, too. And pap is gross. No offense to the Bantu people. But I was, now that you bring up pap, using this definition:

        “something lacking solid value or substance”

        Which is kind of how I feel about the whole plant intelligence debate.

        • Mountain says:

          “Well, vegamite [sic] is vegan, too.”

          And I said, “Oh, you don’t come from a land down under.”

        • Mountain says:

          “And pap is gross.”

          You need to check your non-Bantu privilege. It’s totes not adorbs. Perhaps you meant: “my cultural limitations interfere with my ability to properly appreciate the greatness of pap.”

          Finally, the definition of pap you used is little more than a Euro-carnist tool of oppression.

          • Taylor says:

            Mountain: I’m guessing you’ve got your tongue in your cheek. But as a matter of interest, and according to that ultimate word oracle, the OED, “pap” originally has a couple of meanings: “breast” and bland, semi-liquid food suitable for babies. The usages go back to the Middle Ages.

          • Mountain says:

            Taylor, I promise you (and everyone else) I would never use the phase “Euro-carnist tool of oppression” in earnest.

    • Mountain says:

      Also, with regard to your use of the word “rotting,” consider the words of David Chang:

      “Many foods are rotted to make them edible at all: olives, chocolate, coffee. And there are those that we rot to improve: pickles, cheese, wine. I find it hilarious that even the freshest foods are seasoned with rot. We dress salads with vinegar, a.k.a. rotten wine.’

      • James says:

        I hate when lawyers take rhetorical flourishes literally. There should be a prison for them. But as to your substantial point, indeed, you are right, and I’ve added a sentence to clarify my final point vis a vis Pollan.
        j

      • James says:

        M–
        You should go back and read the Pollan piece in conjunction with the Sacks piece to apprecaite how much more careful Sacks is to avoid the implication of plant intelligence than Pollan is. Also, I ALWAYS read the footnotes. If you are referring to this one:

        In 1859, Hermann von Helmholtz was able to measure the speed of nerve conduction at 80 feet per second. If we speed up a time-lapse film of plant movement by a thousandfold, plant behaviors start to look animal-like and may even appear “intentional.”

        I don’t see how it matters to my assessment of Sacks’ piece. If anything, it seems to support the critical distinction between plants and animals that leads to a mental life for one and not the other.

        j

        • Mountain says:

          Sacks is more careful than Pollan in his discussion of plant intelligence. One would expect a professor of neurology to discuss matters more carefully than a journalist & advocate. Certainly, Sacks’ article is not an endorsement of Pollan, but there’s a lot more overlap in their views than divergence.

          The footnote comment was primarily a DFW reference, but it also argues that plants and animals have much more in common than is commonly thought, that perceived differences have more to do with our perception of timescales than true differences. Doesn’t mean plants actually “think,” but they perceive and behave much as we do.

          • Taylor says:

            The word “perception” typically implies conscious experience. The claim that plants consciously experience anything is strongly doubted by, it appears, most scientists and researchers. On the other hand, science is revealing that plants are amazingly sophisticated in their (non-conscious) responses to their environments.

            As the authors of “Do Plants Have Brains?” (see link above) say, “To unify plants and animals under a single ‘conceptual umbrella’ when there really isn’t one, creates a genuine problem. For one thing, there is good evidence that plants and animals do not share a common ancestor to the exclusion of all other organisms on the planet. Fungi and the many single-celled organisms that have nuclei get in the way. A unifying umbrella would both disguise this reality and undermine the utility of the metaphor. When a metaphor is no longer recognized as such, fallacy becomes the rule of the day.”

          • Mountain says:

            Taylor, the implications of the word “perception” really depend on context. Many, and possibly most scientists would agree that plants perceive and respond to the world around them, but very few if any would argue that plants have consciousness.

            I want to be clear that I’m not arguing for extending moral consideration to plants. I’m not even ready to extend moral consideration to insects. But in each case, we keep discovering that there is much more going on than we anticipated. The spontaneous order of insects and the decentralized networks of plants are both fascinating, and possible models for our own future. The knee-jerk delineations between us and them doesn’t sit well with me.

        • Mountain says:

          Finally (maybe), the Flying Spaghetti Monster is awesome, a recent creation to mock the advocates of creationism and intelligent design. Considering his ties to the Freedom From Religion Foundation, I suspect Sacks shares (or would share) my appreciation of the FSM.

          • Ellen K says:

            Much appreciation to you all (J, T and M) for a fascinating morning read.

            Love FFRF ever since father gave me gift subscription.

            And nice summary M: agnosticism and wonder linked with eastern perspective of profound interconnectedness are my defaults (“There are more things in heaven and earth, Horatio…”)

  4. Laura says:

    People who espouse plant sentience are only demonstrating their own plant-like lack of awareness and thus should be put in my salad :) (Yes I know this may be deleted, I can’t behave.) But great article here, and Michael Pollan?…ugh, obvious industry advocate, has proved his total lack of credibility.

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