New Take on Human Nature: Are Stone Age emotions are still at war with our high-tech sophistication?
Edward O. Wilson of Harvard University knows the terrifying power of the nest firsthand—and first-ankle, crook of the knee, any patch of skin that happened to be unsheathed as the eminent evolutionary biologist has crept through tropical rainforests studying some of the most aggressive ant species in the world. Ants are a wildly successful sector of nature’s bestiary, accounting for maybe a quarter of all terrestrial animal matter—the same percentage of biomass that we humans can claim. They’re found on every continent save Antarctica and in just about every possible setting, and though you may dislike ants at a picnic, you’d dislike even more a park that was scrubbed antiseptically ant-free.
As Wilson has learned through painful experience, ants will defend their nest vigorously, violently, to the death if need be; and the more elaborate the dwelling, the more ferocious the homeland security system. In the forest canopies of equatorial Africa and Asia, weaver ants construct spectacular swaglike nests of leaves stitched together with silken threads extracted from the colony’s larval ranks. Should any creature venture within smelling distance of the nests, weaver ant soldiers will boil out to bite and spray bullets of formic acid. In the Solomon Islands during World War II, Wilson writes, “marine snipers climbing into trees were said to fear weaver ants as much as they did the Japanese.”
In his newly published The Social Conquest of the Earth—the 27th book from this two-time winner of the Pulitzer Prize—Wilson argues the nest is central to understanding the ecological dominance not only of ants, but of human beings, too. Ants rule the microhabitats they occupy, consigning other insects and small animals to life at the margins; humans own the macroworld, Wilson says, which we have transformed so radically and rapidly that we now qualify as a kind of geological force. How did we and the ants gain our superpowers? By being super-cooperators, groupies of the group, willing to set aside our small, selfish desires and I-minded drive to join forces and seize opportunity as a self-sacrificing, hive-minded tribe. There are plenty of social animals in the world, animals that benefit by living in groups of greater or lesser cohesiveness. Very few species, however, have made the leap from merely social to eusocial, “eu-” meaning true. To qualify as eusocial, in Wilson’s definition, animals must live in multigenerational communities, practice division of labor and behave altruistically, ready to sacrifice “at least some of their personal interests to that of the group.” It’s tough to be a eusocialist. Wouldn’t you rather just grab, gulp and go? Yet the payoffs of sustained cooperation can be huge. Eusociality, Wilson writes, “was one of the major innovations in the history of life,” comparable to the conquest of land by aquatic animals, or the invention of wings or flowers. Eusociality, he argues, “created superorganisms, the next level of biological complexity above that of organisms.” The spur to that exalted state, he says, was always a patch of prized real estate, a focal point luring group members back each day and pulling them closer together until finally they called it home. “All animal species that have achieved eusociality, without exception, at first built nests that they defended from enemies,” Wilson writes. An anthill. A beehive. A crackling campfire around which the cave kids could play, the cave elders stay and the buffalo strips blacken all day. Trespassers, of course, would be stoned on sight.