Anyway, in this book, Mr. Wilson damns the torpedoes and charges full steam ahead to explore one crucially important aspect of genetic influence on behavior: the development of social species. His expertise is with ants, who along with bees constitute the only social species other than humans. Mr. Wilson brings his vast expertise on ants to bear on the question of the evolution of human sociality.
His key finding is that insects developed sociality only when they had nests that required defending. This led to the stratification of groups of such insects into different classes: workers, soldiers, queens, and so forth. Because they were genetically identical, no individual needed to compete with any other individual in the group for reproductive success. A soldier could sacrifice its life for the colony without endangering its genetic future.
In case you’re wondering how insects with supposedly identical genes could develop into different creatures (large soldiers with big mandibles versus small workers, etc), the answer lies in the development process. The genetic complement of each ant contains the instructions to become a worker, a soldier, or another type; differences in chemical environment lead ant larvae to develop into different forms.
But early humans didn’t have a nest, did they? Well, actually they DID: the territory that they claimed as their own. Each human hunter-gatherer band had its own territory that had to be defended in much the same way that the ants’ nest or the beehive had to be defended. The success of each individual human depended mightily upon the success of the band as a whole. One for all and all for one – that’s what made us a social species.
It’s true that other species have their territories: birds stake out their territories with their singing; big cats declare their territory by spray-marking, and so on. But in these species, territorial claims are made by individuals, not groups. That’s what made humans, ants, and bees social: the territory belonged to the group, not the individual.
Here Mr. Wilson forthrightly contradicts long-established scientific convention: he comes out flatly in favor of something called “group selection”. The debate concerns the possibility that natural selection operates on groups of individuals as well as individuals. For decades, the going wisdom was that group selection was sabotaged by “free riders” – individuals who refuse to make contributions to the group but enjoy the benefits of group action. The theory was that, whenever a group arose that, by engaging in some sort of cooperative behavior, could get ahead in the world, the group would inevitably be brought down by free riders who took advantage of the group’s strength without in any way contributing to that strength. The free riders would be successful and would multiply within the group, until eventually the group would consist solely of free riders, and would no longer cooperate as it once did. This was why evolutionary theorists rejected the notion of group selection. It just couldn’t happen, they maintained.