Book Review: The Light Eaters

By Karen Melton, Sylvanian and Southeastern Pennsylvania Group Volunteer

As soon as I heard the title of this book published in May, I ordered a copy -- ‘A New Understanding of Life on Earth’ sounded irresistible. Apparently not just to me, a week after publication it was a New York Times Bestseller of nonfiction print hardcovers. Author Zoe Schlanger is an award-winning science writer who has done extensive reporting about the environment and climate change. She became fascinated by what was occurring in the field of botany and shares the current state of research in this book.

An interesting legacy of the research she explains began with the publication of The Secret Life of Plants in 1973, a book filled with pseudoscience and mystical claims about the capabilities of plants including some you’ve probably heard, for example, that plants prefer classical music. While some of these ideas were immensely popular with the general public, there was an enormous backlash from the scientific community that reverberated for decades -- funding dried up for any research suggesting that plants had capabilities reflecting intention, and words like behavior, intelligence and even communication became taboo. Careers could be ruined by crossing the line.
Then came a period where genetics was thought to be the answer to every question – identify a trait or action, then look for the gene that explains it. Once again, funding sources reflected this thinking and discouraged most others.

As laboratory technologies have progressed, however, it is becoming possible to perform tests of plant functions that have previously been undetectable. Schlanger takes us on a tour of studies and her visits with preeminent botanists and their labs where we learn that plants most certainly do have ‘behaviors’ regardless of the words used to describe them. The exact mechanisms for most of them are yet to be understood, but here are some of the fascinating topics of research she learns about and shares.

Plants are able to detect and communicate the presence of chewing caterpillars and to deploy defenses such as noxious chemicals.

Plants can communicate to the surrounding community of plants or just specifically to those genetically related to them.

Ferns can have up to 720 pairs of chromosomes (humans have 23).

In response to an external stimulus such as wind, plants can rapidly alter their genetics to grow differently – less tall, for example.

Plants demonstrate capabilities that can best be described as counting and memory.

There is ongoing controversy in the scientific community around the language used to describe the ‘behaviors’ of plants and to avoid anthropomorphizing words such as “conscious” and “intelligent”. Schlanger summarizes the thinking of Anthony Trewevas, a plant physiologist at the University of Edinburgh as follows: “the brain is just one strategy for building intelligence and consciousness. Plants simply took a different evolutionary route, according to their needs: their attention and awareness is localized in each of their parts, but each of their parts communicates and strategizes across the whole, producing consciousness all the same.”

We get to hear the details of experiments that demonstrate extraordinary capabilities, and hint at many beyond our current methods of detection. In talking about creating chemicals she writes “Plants are geniuses at synthesizing chemical compounds . . . .  Their precision and aptitude for this is beyond any other organism, and its fair to say it constitutes a completely additional sense that continues to shock researchers on a regular basis.”

In concluding this remarkable book, Schlagel advocates respect for plants, and beyond that, legal rights. It is we humans who have mostly considered plants as dumb, insensate organisms when they are anything but. Read The Light Eaters and you will never again look at the plants around you the same.


This blog was included as part of the June 2024 Sylvanian newsletter. Please click here to check out more articles from this edition!