A few weeks back, deep into one of Nick Lane's books on the origins of life, I was suddenly dope-slapped by two new books announcing themselves. Their subjects have possessed me for decades: plants, and this wonder-full planet on which we live. I had to put Mr. Lane aside.
The books are Zoe Schlanger's The Light Eaters and Ferris Jabr's Becoming Earth. Both are excellent, of the same awe-inspiring natural history ilk as Ed Yong's An Immense World and Merlin Sheldrake's Entangled Life. Each deserves a long post of its own, but I've picked one to focus on: Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth.
This book on plants is also about science changing its mind, even as it happens. Interestingly, science is simultaneously changing its conception of what mind even is.
The subtitle's phrase "plant intelligence" might remind some of The Secret Life of Plants, a pseudoscientific book from the early 1970s. Schlanger is aware of this, and starts off by explaining what that was and what this is. This, we discover, is the very latest science, describing how light eaters -- orchids, sequoias, wheat, kudzu, Venus flytraps -- are far more intricate and incredible, and yes, even intelligent, than you think. And they are all fueled by electromagnetic waves from a nearby star.
Poet-farmer Wendell Berry famously said that eating is an agricultural act. He's right, whether you're carnivore or vegetarian or vegan or omnivore. But Wendell is wrong if you're a plant, in which case eating is a cosmic act. Through photosynthesis plants spin sunlight and water into energy. That trick, what Nick Lane calls one of the "10 great inventions of evolution," then feeds all of us. But you already knew that. What Zoe Schlanger is here to tell you is that plants not only eat light, but make weather. And talk amongst themselves. They can mimic animals, or actively direct bat sonar to aid in pollination, or take on the appearance of surrounding plants in real time, or forage for food of the non-solar, meaty kind. They feel pressure. They hear.
Schlanger starts with a quick survey of European thinking about plants, going back to the Greek philosophers. Back then, unlike Aristotle, Theophrastus took what might be considered a holistic view of plants, "a path Western thought did not take," Schlanger says. In his honor, the photo accompanying this review is a lovely "weed" in my yard called velvet leaf -- Abutilon theophrasti.
There are myriad floral mysteries on that path yet to be teased apart: A fern has been found with 720 pairs of chromosomes (we puny humans have but 23). Why? Mushrooms (yeah, I know, technically not plants) have thousands of genders. Darwin, known for his studies of birds, later in life studied plants, observing root communication long before "mycorrhiza" became part of the lexicon, and Schlanger devotes a chapter to new plant communication studies. (Note: when I write "plant(s)" it means some plants that have been studied - not every single species.)
I think my favorite chapter of Light Eaters is the one entitled "Alive to Feeling," wherein we learn that plants feel -- and how plants feel. Not too surprisingly, eating external electromagnetic waves begets internal electromagnetic waves. Talk about cosmic. More surprisingly, plants feel sensations in much the same way as we do. Scientists have been poking and pulling apart plants going back way before Darwin, but, as with subjects from genetics to whale communication, it's only been in the last couple decades that advances in technology have led to massive and often unexpected new discoveries.
Here's your word of the day: Thigmomorphogenesis. Science-speak for plants changing growth patterns (shape) in response to touch. Not over generations, but nearly in real time. How does this happen? Touch > electricity > nervous systems > cell membranes > Ion channels. Sound familiar? All that = Us. Plants sense much the same way we do! Move over genetics, electrophysiology is back.
Vibration is making waves too. Sound is vibration, for us the movement of cilia in our ears. Plant hearing, too, can be triggered by movement of little hairs. Another new word: Phytoacoustics. The changing cavitation sounds of fluids bubbling through a plant also may be a means of communication.
Of course, the key to touch and sound having any real meaning is memory -- mind. Wouldn't you know it, plants have minds. Waves +electricity = consciousness. Which includes time and duration, and not just of solar cycles and the like. Flowers open when they know a pollinator is about to visit, based on its previous visits. There is, of course, no brain. The whole plant is a brain.
Our animal brains are still trying to comprehend this, haltingly discovering more as we go. Not mentioned in Light Eaters: the sunlight plants eat is of different frequencies. What unexplored roles might that play? We learned a while ago that flowers look different to us under different wavelengths, some of which pollinators can see and we can’t. What else might be going on? And why is photosynthesis so inefficient (somewhere between 1% and 30%, depending)?
Or maybe we're just way too ignorant. A recent theory, bringing quantum physics to the botany party, says the light eaters are nearly 100% efficient. Can't beat that.
-Jake Vail is an Information Services Assistant at Lawrence Public Library.
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