Think of a Tree - Part 3, Of Plants and People
Science is the name we've given the human quest to understand how everything works. The science concerned specifically with understanding how life works is called biology.
Humans have been acquiring biological information for thousands of years, and a system has been developed to organize this information into categories based on characteristics. The system is called taxonomy. An eighteenth century Swedish biologist named Carl Linnaeus is credited with originating the first modern taxonomic system, in which he described two broad categories that encompassed all the living world. Linnaeus called these groupings kingdoms. One of his kingdoms he called "Vegitabilia" and it included all plant life. The other category was dubbed "Animalia" and that kingdom contained all other known forms of life. Think of that for a moment. Two broad groupings — plants and everything else. Worms, whales, snails, vultures, spiders, jellyfish, lightning bugs, lizards and rats, are all classified as belonging to the same big group as us. The only living creatures not in our group? Plants.
Modern taxonomy now includes several other kingdoms such as Bacteria, Fungi and Protista, and the kingdom Linnaeus termed Vegitabilia is now called Plantae, but the distinct separation between animals and plants remains intact. Humans have more in common with leeches than we do with plants.
One of the hallmarks of plant life, a characteristic that sets plants completely apart from any other form of life, is the ability to derive energy directly from the sun through the process known as photosynthesis. The sun is the original source of all energy on earth, and among all living organisms only green plants have the ability to tap into it. This means that all energy consumed by humans and other animals is passed along, directly or indirectly, from plants. This fact alone makes the Plantae kingdom an absolutely essential component of life as we know it. You might suppose a relationship of total dependence would cause us to regard with great respect or even reverence that thing on which we depend for our very existence, and at one time it did, but it is not so much the case anymore. Plants are too common to be held in such high esteem. Plants are everywhere on earth, including in deserts, oceans and in the most densely populated urban areas, making up more than eighty percent of the planet's total biomass. In greener places like western North Carolina we are surrounded by literally uncountable numbers of plants every single day. It can be difficult to sustain conscious awareness of something that is seen as an ordinary part of everyday life, and there is no hope of having wonder or respect without first having awareness. Plants become invisible after awhile. We see them so often that we stop seeing them.
It doesn't help that plants seem to be inanimate. To human eyes, plants don't move unless the wind blows and pushes them around. Plants can't get up and go anywhere, but locomotion is not the only form of movement. Reason tells us plants must be moving at least some of the time, otherwise how would something that starts out as a seed end up in a completely different form, several inches, or several hundred feet, in height? There are all sorts of self-propelled physical movements performed by plants, usually occurring at a rate too slow for people to notice. Plants also go through a discernible life process, beginning with germination, followed by growth into maturity, reproduction, physical decline and eventual death. Therein lies the ultimate proof of life in plants — they can die.
Plants can die, but they can't see or hear or talk in any manner familiar to us. The latest biological research indicates that plants can certainly sense the world around them and react to it, and they communicate among themselves and with other non-plant species by means of chemical and electromagnetic signals. The problem is that the ways of plants are substantially different than human ways, which for the longest time caused people to think plants had nothing going on beyond what was immediately obvious to casual observation. Plants might be living things, according to this now outdated perspective, but they have neither intelligence nor agency. Proof of this viewpoint is found in the common although inappropriate term for a person with little or no brain function as being a "vegetable".
As regards anatomy, the physical structure of any given plant is fundamentally different than that of humans or any other members of the Animalia kingdom. No eyes, ears or mouth, no face, no arms or legs, no hands or feet — plants have no body parts that are recognizably the same as ours. Plants don't look like us. They don't act like us and we can't communicate with them.
Plants are useful, though. Humans breathe in what plants exhale, we eat plants, feed them to livestock, use them for medicines, make structures, implements, paper and clothing out of them and burn them for fuel. As a species, humans developed alongside plants as an ever-present reality and we took full advantage of all the wonderful properties they contain. Utilizing plants usually requires manipulating them in some way, taking something from them and very often killing them in the process, and that has been the greater portion of the human relationship with plants over the span of time we have existed as a species. We use plants as we please, but there is more to the relationship than that.
In earlier times, humans were more immediately aware of their dependence on plants. Failure of a staple crop like corn or rice could cause collapse of a tribe or an entire city from starvation, so people behaved in a manner signifying the importance of that particular plant to the survival of human life. Certain plants were deified, typically in human form so we could relate to them better, and rituals were performed to show respect and ensure a good harvest. In modern societies we have largely outgrown this behavior. Science and technological innovation have allowed us to bend plants to our will, manipulating them to a degree our forebears could only dream of. Still, echoes of the old relationship might be recognized in events such as an annual springtime flower show or late summer apple festival. These affairs are more quaint than meaningful to us because now grains and vegetables come from supermarkets and are seemingly always available. There's no need anymore to thank the plants.
Significantly, although there is an apparent disconnect in our awareness of the ongoing human dependence on plants, we still find some degree of satisfaction in simply having them around. People love parks, greenways, woods, fields and forests. People who are fortunate enough to have their own house with some parcel of property attached will almost universally prefer that their little patch of land be covered with green and growing things, even if nothing more than a lawn. Humans invented the idea of public gardens and arboreta, spaces specifically designated for growing and showing plants with no higher purpose in mind than to provide a place for people to come and mingle with these other life forms, enjoy them and come to better understanding and appreciation.
The evidence suggests that, beyond the necessity of breathing the oxygen plants produce, or eating them to stay alive, or utilizing them in innumerable practical ways, humans desire the company of plants. We want to be around them. There is some reason to think we might actually need plants for our emotional well-being.
To be continued...
