Though he celebrated his 79th birthday last month, Dr. Wilson is generating a storm of literary output that would be impressive for someone half his age. “The Superorganism,” with Bert Hölldobler, a new book with information on termites, wasps, bees and ants, will be published in November. Dr. Wilson is at work on his first novel. He is preparing a treatise on the forces of social evolution, which seems likely to apply to people the lessons evident in ant colonies. And he is engaged in another fight.

Image FIRST LOVE Edward O. Wilson studies the genetics of ant colonies. Credit... Rick Friedman for The New York Times

Beneath his gentle manner and Southern charm, Dr. Wilson is a scrapper. He grew up in Alabama and Florida, where the local custom with respect to fistfights was that one could prevail or get knocked out, with no third option. “I never picked a fight,” he wrote in “Naturalist,” his autobiography. “But once started I never quit, even when losing, until the other boy gave up or an adult mercifully pulled us apart.”

Dr. Wilson was not picking a fight when he published “Sociobiology” in 1975, a synthesis of ideas about the evolution of social behavior. He asserted that many human behaviors had a genetic basis, an idea then disputed by many social scientists and by Marxists intent on remaking humanity. Dr. Wilson was amazed at what ensued, which he describes as a long campaign of verbal assault and harassment with a distinctly Marxist flavor led by two Harvard colleagues, Richard C. Lewontin and Stephen Jay Gould.

The new fight is one Dr. Wilson has picked. It concerns a central feature of evolution, one with considerable bearing on human social behaviors. The issue is the level at which evolution operates. Many evolutionary biologists have been persuaded, by works like “The Selfish Gene” by Richard Dawkins, that the gene is the only level at which natural selection acts. Dr. Wilson, changing his mind because of new data about the genetics of ant colonies, now believes that natural selection operates at many levels, including at the level of a social group.

It is through multilevel or group-level selection — favoring the survival of one group of organisms over another — that evolution has in Dr. Wilson’s view brought into being the many essential genes that benefit the group at the individual’s expense. In humans, these may include genes that underlie generosity, moral constraints, even religious behavior. Such traits are difficult to account for, though not impossible, on the view that natural selection favors only behaviors that help the individual to survive and leave more children.