…and whatsoever Adam called every living creature,
that was the name thereof." Genesis 2:19.
"The first thing in science is to know one thing from another."
Karl von Linne, a.k.a. Carolus Linnaeus
(April, 2011) Each morning while completing breakfast and the daily Sudoku puzzle, I jot down the names of the birds I see through the kitchen window. Unless my wife chases me out of the kitchen prematurely, the list always includes at least 15 species; it got up to 24 once this winter. This is not
remarkable; our yard provides a variety of trees and shrubs for shelter, and birds learn quickly that seeds and suet are always there for them. It is also not remarkable that I should be able to recognize the different species; I knew many of them before I became a biologist because my parents encouraged me to be curious about such things. I have many friends who are not
biologists who have the same ability.
How this happens is illustrated by my friend, Claire, who will be three this month. As a baby, one of the first things she learned to do with her hands was to point at things, even before she could say her first word. This is the universal expression of curiosity. By this time last year, having more or less mastered the art of walking, she was starting
to venture into the world, and everything she saw was new and unknown. Her vocabulary then was dominated by two words: "What that?" Those two words were a wise choice; the first step toward knowing is to learn what things are called, and by the end of summer she could name many generic categories of things like rocks, flowers, birds, bugs, worms, leaves, grass, and trees. By
the end of the coming summer she will know robins, sparrows and cardinals, as well as dandelions, violets and clover. Everyone who reads this will have gone through the same process, at about the same age.
Human societies had to go through much the same process in order to survive. Prehistoric parents had to be able to name things so they could teach their children which plants were good to eat and which were poisonous, and which animals could be eaten versus which would eat them. Names were practical and necessary, and when people lived their whole lives
within a few miles of their birthplace, they would know the names of all of the local plants and animals. Inevitably, though, societies became more complex, and as new means of travel were invented, people were exposed to new plants and animals that were quite unlike the ones in their native lands. As ships became capable of crossing oceans and the New World began to be
explored, the numbers of plants and animals kept growing, and since many of them were either economically valuable or of interest to a curious public, naming them became a matter of scientific importance.
In the mid-1700s a Swedish physician, Karl von Linne, somewhat naively set out to name every living thing in the world by assigning "scientific names" which consisted of two parts, a noun and a modifying adjective. At that time, all scientific writing in Western culture was done in Latin, and von Linne even Latinized his own name to Carolus Linnaeus.
People sent him newly discovered plants and animals from all over the world, and like Adam, he named them… over 4,000 animals and 6,000 plants. Ironically, he suffered a stroke and lost the ability to recall names, even his own, but the system he started is still in use.
When I entered college in 1951, biology textbooks taught that there were about a million species of animals and perhaps 250,000 kinds of plants in the world. Throughout my career these numbers kept growing, and biologists now estimate that more than 30 million species exist, with new ones being discovered every day. This keeps a few specialists busy
naming things, but with rules for naming being standardized and computers available for keeping track of them, it is no longer a major division of the biological sciences. The question has changed from "What shall we call them?" to "Why are there so many of them in the first place?"
The man who gave the best answer to that question was one of the founders of modern ecology, G. E. Hutchinson. On vacation in Sicily in the 1950s, he visited a cave where some bones were encrusted in limestone. According to local legend, the bones were the remains of Santa Rosalia, a female hermit who had lived there around 1100 AD. Hutchinson was more
interested in several species of insects he found in the cave; he published a paper about them and, in a jocular mood, suggested that perhaps Santa Rosalia might become the patron saint of evolutionary studies because she led him to a theory that explains why so many different kinds of animals exist. This turned out to be a better joke than he intended, because a few years
later someone investigated the bones more carefully and found they were not human, but rather, the remains of a goat. Santa Rosalia, if she ever existed at all, must have lived in some other cave.
Skeletal humor aside, Hutchinson’s theory has come to have great relevance in present-day ecological problems. Briefly stated, he proposed that the presence of many different kinds of animals gives an ecosystem stability. In simple ecosystems where there are only a few species at each level in the food chain, when one population gets out of control it
will disrupt the populations of all of the other species. The classic example of this is the Canadian Arctic, where the climate is so severe that few species can survive. The food chain there is a simple linear series: grasses and sedges are eaten by lemmings, which are fed on by arctic foxes and snowy owls (there are a few other species, but they are small in numbers). Every
few years the lemming populations overproduce; the snowy owls and arctic foxes feast on them and have large litters, but the lemmings keep reproducing until they destroy all of the grasses, and then they crash. The foxes then starve in large numbers, the owls are able to migrate south searching for food, often as far as Emmitsburg, but most of them do not survive. Thus the
arctic ecosystem is unstable, and exists in a permanent "boom and bust" cycle.
In temperate and tropical ecosystems where more species are present, food chains are web-like rather than linear, and ecosystems are more stable unless they are disturbed by human activities. However, as the human population expands, we disrupt natural ecosystems by removing native species of plants and animals and replacing them with crops and domestic
livestock, or worse, by cities and residential developments. This leads to instability in the form of outbreaks of pests… starlings, pigeons, Japanese beetles, stinkbugs, gypsy moths, fire ants, kudzu vines, multiflora rose… often alien organisms that are brought in accidentally, but sometimes intentionally.
The term used by ecologists for the multitude of species of plants and animals that exist in normal ecosystems is biodiversity. Hutchinson showed us why it is important, and nowadays most people have heard of it. But it appears that few people realize how important it is. The need to preserve it is the reason ecologists are so concerned about preserving
endangered species. Individually, endangered species may sound trivial; often they have silly names, like the Furbish Lousewort or the spotted owl, and often they live where we wish to build something. If only one such species became extinct, it might not matter. But when many are on the verge of extinction, the stability of ecosystems hangs in the balance.
Claire has not yet heard of biodiversity, but she is learning about it. She remembers the tree frog we caught last summer, and she is eager to go to the Great Forest behind my house to look for the spring peepers we hear singing there. If we catch one, I will encourage her to name it Hyla, the name Linnaeus gave it; and by the end of summer she will know
how to tell tree frogs from toads and regular frogs. Learning starts slowly, but it picks up speed. Before we know it she will be in school and will learn words like biodiversity. Let us hope that when she is my age there will still be biodiversity for her to see, and to protect her world.
Read other articles by Bill Meredith
