History and the Genes

Man is at once the product and the prisoner of his genes. Civilizations flourish and decay, like dinosaurs, in obedience to irreversible genetic decrees. All the marvelous fruits of man's distinctive intelligence, of his ascent from the apes, owe their conception not to reason but to the unreasoning mandates of heredity. The human evolutionary course is determined by the microscopic chromosomes that constitute the only true inheritance passed from one generation to the next.

These provocative opinions appear in The Evolution of Man and Society (George Allen & Unwin, Ltd., London), the latest book by Cyril Dean Darlington, 65, a British geneticist, Fellow of the Royal Society and Sherardian Professor of Botany at Oxford. None of these academic credentials describe Darlington's true vocation. He is an intellectual maverick, dedicated to setting the scientific Establishment on its ear. His new book is the culmination of the author's long assault on the complacent conviction, still defended by many social scientists, that man represents a kind of dead end on the evolutionary trail: a resplendent terminal species that, if not perfect, is at least complete.

Cultural Evolution. This position rests on the argument that, some 25,000 to 100,000 years ago, modern man, Homo sapiens, was developed by biological evolution. Since then, goes the theory, cultural evolution has taken over.

The opposite side of the argument is that culture itself is genetic—that is, hereditary. "What I am trying to say," explains the author, "is that what people call social behavior always has a biological basis. The character of individuals, families, groups, classes, nations —right underneath these things are the biological foundations." Biological evolution has not been replaced by cultural evolution; it is actually responsible for it.

Darlington states, for instance, that the incest taboo, which is not only common to all human societies but is regarded as a moral decision to avoid the hazards of inbreeding, is, in fact, instinctive. Just as evolution forbids self-pollination to the hermaphrodite flower, so evolution prohibits incest in man. "In a stable world," he writes, "[inbreeding] allows, it even guarantees, success. But in a changing world it brings disaster. For the inbred race in plants, animals or men is uniform and predictable like a variety of potato. Faced with new situations, new environments, it is quickly displaced in competition with the adaptable out-breeding races or species."

In developing this point, Darlington traces the fall of past dynasties and kingdoms. They vanished, he argues, for fundamentally the same reason: once a ruling class fixed itself in power, it sought to conserve that power by inbreeding—by denying the infusion of new genetic patterns that might have refreshed the stock. It was this habit, says Darlington, that expedited the decline of the Pharaohs, the Ptolemies and the Caesars.