Zoë Schlanger believes that we don’t think about plants nearly enough and hopes to correct that deficiency. The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth invites us to open our animal-eyes to the familiar, yet oddly alien, members of the plant kingdom. Schlanger’s extensive review of cutting-edge plant research reveals that our green neighbors have numerous tricks up their shady sleeves. They are much more active and intriguing than most of us suspect. She’s determined arouse our curiosity and cure us of “plant blindness.”
We know plants are the foundation of our terrestrial food webs. They harvest light energy and use it to convert simple chemicals into the complex biomolecules they use for food, growth, and reproduction. We animals can’t harvest light to make our food, so we are utterly dependent on the “light eaters” to fill our open mouths. If these creatures are so vital to our existence, why don’t we see them? Schlanger believes the fault lies with our cultural preferences for beings most like us. Our attention is drawn to mobile responsive “animated” animals. Though rooted in place, our vegetative friends also move and respond, but differently than we do. Schlanger points out the Latin word for vegetabilis refers to flourishing, alive, and growing, yet we crudely use the term vegetative to describe humans who can’t move and respond. How did we get it so wrong?
Schlanger is on a mission to help us change our minds about plants. takes readers on deep dives into intriguing and controversial topics such as plant senses, behavior, intelligence, communication, and neurobiology. These ideas have been circulating among plant scientists for generations. However, inconsistent research results, technological limitations, and the specter of pseudoscience dried up funding and stymied progress for decades. The careful, and often conservative, processes of scientific inquiry restrained botanists from making rash claims about plants in their publications. However, in private conversations with researchers, Schlanger finds them awed and astonished by the things their quiet green partners are up to. Armed with new research tools and multidisciplinary approaches, they are cautiously pushing the boundaries of plant science once again. In The Light Eaters, Schlanger pulls back the curtain to let readers in on the fun.
Instead of building slowly by introducing readers to the myriad ways plant respond to their environments, Schlanger drops readers into the deep and contentious end of the pool—plant consciousness and intelligence. While swimming in this pool, we’re cautioned to avoid viewing plants as green animals, mystical New Age beings, or Tolkien’s heroic Ents. Using examples detailed enough to amaze, she gives us insight into how plants struggle, thrive, and overcome challenges using uniquely green approaches.
Each thought-provoking chapter provides drama, delight, and surprise. For example, we learn how plants “know” they’re being attacked by caterpillars, how (despite lacking a nervous system) they mount a coordinated chemical defense to the attack, and release chemicals that signal other plants of the potential risk. We also learn that chemicals released by an attacked plant are detected by parasitic wasps who then attack the caterpillar! Is this evidence of plant consciousness, intention, intelligence, and tool use? This short description doesn’t do the story justice, but Schlanger does! She describes the sounds the caterpillars make when chewing, how researchers puzzled out how plants’ responses, and the gruesome fates of the parasitized caterpillars. After reading, I wanted to go hang out with my plants, give them a drink, and (gently) touch their leaves.
If I could assign one chapter for my botany students to read, it would be Chapter 8, The Scientist and the Chameleon Vine. This chapter describes a vine that changes the shape, color, and venation of its leaves to match those of the host plant it climbs upon. The vine’s leaves are “normal” on the ground, but when on the host, the vine’s leaves mimic the host’s, so the vine supports two different types of leaves. How does this happen? There are competing hypotheses and ample drama. One scientist proposed that the vine can “see” its host’s leaves clearly enough to mimic them. Another proposed that the microbes on the host plant emit a cloud of chemicals that change the growth of the vine leaves! It’s a beautiful example of the intense interconnections within a biological community.
Concepts introduced early in the book are reinforced throughout the narrative, adding strength to conclusions drawn by incredulous plant scientists. Readers should be prepared for many interesting detours into history, psychology, animal behavior, and the philosophy of science along the way. One caveat: although warning readers not to imagine plants as green people, Schlanger frequently slips into anthropomorphism (using “human terms to describe green lives”). I understand that this device draws readers into her story, but I don’t think it was necessary. As a scientist, I was trained to consider this type of language taboo. I found descriptions of plants having intention, deciding, counting, and caring for their “babies” distracting. This type of language works against Schlanger’s thesis that to truly remedy our “plant blindness” we need to be aware of our zoo-centric biases and careful with our language.
The book ends as it begins, with an intriguing and controversial proposition. If plants are conscious intelligent beings, should they be given ethical consideration and moral standing? During the last two centuries, the United States has progressively expanded legal rights to different groups of humans, animals, and even inanimate objects (e.g. corporations). Of course, we need plants to feed, shelter, and clothe us, but could a recognition of the complexity of plants encourage us to restrain ourselves from “indiscriminate killing and thoughtless destruction” of our leafy neighbors? As a Christian, I take the command to serve and protect the garden seriously. Practically, when we obey this command, it helps us help ourselves through the wise use of resources. In a less anthropocentric view, wise stewardship can support all of creation’s ability to glorify our Creator. What does it look like for a plant to glorify its Creator? This book opens the door for some interesting possibilities.
One Response
Thank you for this enlightening review; I look forward to reading the book!