The Earth is no Garden of Eden to David Barash, who blames the blemished state of our planet on human history. Unlike biblical fundamentalists however, Barash accepts the scientific evidence of evolution and discovers in our biological past an explanation for our present conundrums.
The author of a textbook on sociobiology and a zoologist at the University of Washington, Barash believes that contending forces within us are out of control. In the context of evolutionary biology, sociobiology--a term popularized by Harvard's E. O. Wilson a decade ago--is an approach to the study of animal behavior that assumes that each species is constrained genetically to behave in a certain way.
This can be a fruitful approach to the study of animal behavior. But many scientists believe that sociobiology is unsatisfactory when it's applied to human behavior. They feel that while the study of animals can tell us a lot about the evolution of behavior, it's simplistic and even dangerous to extrapolate from the behavior of animals to the behavior of human beings.
Barash is this latter kind of sociobiologist. He has discerned a tension between what he sees as the two themes of human behavior. The first is our biological inheritance. Hominids in a family that includes the great apes, we are obliged by nature to live in family groups and compete with each other for our livelihoods. Barash suggests that our biological nature is evolving slowly--hence the tortoise of the title. But Homo sapiens, unique in the animal world, has developed language, culture and technology, the last of which is advancing at a phenomenal rate--the hare of the title. With both tortoise and hare pulling us, it's no wonder we have trouble staying on a safe course. Technology has made man exceedingly dangerous, for he develops weapons without developing biologic defenses. Nature is unable to evolve fast enough to provide defenses against weapons that are extensions of our bodies--e.g., guns and bombs--but not biologically part of them.
The hyphen in ape-man, he says, is the longest line imaginable. The power to make machines we cannot control, combined with what he sees as a perversion of our behavior into pathology, is thus a recipe for global destruction. The purpose of his book is an analysis of what has gone wrong with both the hare and the tortoise. Implicit in its publication is the hope that understanding these forces can help us prevent disaster.
It is difficult to argue with his vision of approaching doom, but it's not hard to find parts of his analysis scientifically and logically flawed. Barash feels that the human female's ability to experience orgasm makes her unique, and thus sets the stage for polygamous relationships among human beings and subsequent male dominance (he describes marriage as a trap to dominate women). Aside from pygmy chimpanzees, which Barash grudgingly admits may have this same sexual experience, researchers have observed what seem to be orgasms in female rhesus macaques. Moreover, William Eberhard, in his recent "Sexual Selection and Animal Genitalia," presents a convincing case that females in many taxa, including mammals, select mates for the kind of sensory stimulation they receive in the process of copulation. Thus human females do not seem to be unique.
We are the only hominid, however, in which ovulation is concealed. Barash presents a hypothesis suggesting that concealed ovulation is the result of selection against those females who, wanting to avoid the pain of childbirth, deliberately avoided copulation when they knew pregnancy would result. The only objection to this idea is that it assumes that these early humans associated copulation with childbirth, an event that occurred nine months later and which is still not always understood as a matter of cause and effect in some human cultures.
Referring to a famous 1963 study of the conditions of overcrowding among Norway rats (they developed many pathologies including cannibalism), Barash sees parallels with human behavior. He suggests that when male rats attack female rats in overcrowded burrows, theirs is "behavior reminiscent of gang rape in human beings." He justifies his extrapolation from rats to people by arguing that this "is done routinely in biomedical research," as though behavior is as predictable as chemical reactions.
He is opposed to the growth of human population and denounces all unrestrained growth in the natural world as "a good description of cancer." He asserts that the green revolution is deceiving, as it only spawned overpopulation that will lead to famine. Modern cities to him are "unnatural," and urban Homo sapiens are "alienated animals," as if cities are more unnatural for human beings than termite mounds are for termites.
Early in the book, he calls cultural evolution "Lamarckian" (a reference to the 18th-Century biologist who believed that evolution worked through the inheritance of acquired traits). This kind of muddled analogy prevents his often interesting collection of ethological anecdotes from evolving into a convincing argument.