For decades, selflessness — as exhibited in eusocial insect colonies where workers sacrifice themselves for the greater good — has been explained in terms of genetic relatedness. Called kin selection, it was a neat solution to the conundrum of selflessness in what was supposedly an every-animal-for-itself evolutionary battle.
One early proponent was now-legendary Harvard biologist E.O. Wilson, a founder of modern sociobiology. Now Wilson is leading the counterattack. [...]
The researchers offer their own alternative theory, based on standard natural selection, but with a twist: After starting with a focus on a single founder, selection moves to the level of colony. From this perspective, a worker ant is something like a cell — part of a larger evolutionary unit, not a unit unto itself.
“Our model proves that looking at a worker ant and asking why it is altruistic is the wrong level of analysis,” said Tarnita. “The important unit is the colony.”