Science Book Review: The Revolutionary Genius of Plants Ch 4-6

Last week I tried to rectify the dearth of botany in my blog coverage by covering the first few chapters of Stefano Mancuso’s The Revolutionary Genius of Plants, and this week we’ll pick up where we left off. Mancuso thinks that we can learn much from plants, not least because they have such different solutions to life’s major challenges. As we discussed, one of those differences is that animals tend to have dedicated organs for various functions while plants tend to spread out functions throughout their bodies. In chapter 4, he brings up what I thought was the most intriguing difference: plants stay put. OK, maybe that’s obvious, but what’s intriguing are the implications Mancuso teases out from it.

As Mancuso points out, animal mobility means that they solve a lot of their problems by moving. Not enough food or water? No need to figure out how to make do with fewer resources, just move somewhere with more. Can’t get along with the individual or species next door? Why figure out how to get along when you can just go somewhere they aren’t. Plants, however, don’t have that option. As a result, they have to find other solutions, or perhaps they have to actually find solutions instead of avoiding the problem if one wants to be especially pointed about the distinction. Now again, this is a broad generalization. Collectively, plants can resolve some issues by dispersing their seeds broadly, enabling their offspring to grow in better conditions. And animals don’t run away from everything; fight-or-flight has two options. But individual plants in general do need to make the most of whatever circumstances they find themselves in.

To do so, plants constantly monitor their environment, collecting data and making decisions based on that data. We humans tend to think of our decision-making as a brain process, but plants don’t have brains. So they make decisions in a more decentralized, and in Mancuso’s telling more democratic, fashion. What follows is a discussion similar to one we had recently about, well, random forests. The “forest” in that case is a machine learning construct named for on an analogy to actual trees and forests, and a random forest is an algorithm that combines many individual algorithm results to give even better answers. Plants operate similarly in the sense of aggregating input from many sources–for example, many roots–to make a better collective decision than an individual root could make. Mancuso connects this to the logic behind democratic governments and policymaking. He even suggests we might be better off with more direct democracy than the representative sort practiced in most democratic nations. He cites some evidence from human societies as well as plant biology (and social insect biology as well). Naturally a botany book doesn’t have a complete solution to all our civics issues (for example, what do you do when a significant fraction of your deciders are getting bad data?), but it does present an interesting way of thinking about the problems.

Once plants have collected data and made a decision, what options do they have to solve problems? In chapter 5, we explore one option: behavior modification. Plants don’t just reward pollinators with sweet calories via nectar to help pay the energy cost of pollination. They also produce and secrete hundreds of compounds that alter the nervous systems of animals and change their behavior. You may know a few of these: caffeine, nicotine, even the original opioids. Our addictions to these chemicals is largely an unintended side effect, but their addictive nature is very much the point as plants use them to get what they need from insects and other animals. Notably, this is one chapter where Mancuso does not advocate mimicking plants, preferring to simply acknowledge the complex relationship plants have with the animals around them that have developed as plants solve the problems of coexistence.

So we don’t necessarily want to use mind control on those around us. Still, I think the underlying idea of staying in place and resolving issues has merit. You can see elements of it in our language. We talk positively about putting down roots in a community, but being rooted can also carry negative connotations of stasis or being left behind. Mancuso is helping us to see that even when plants stay in one location, they are dynamic and adaptive. Maybe as we fully appreciate what plants can do, our plant-based idioms will adjust accordingly.