Relatedness, Conflict, and the Evolution of Eusociality
The evolution of sterile worker castes in social insects – like these Polistes dominula wasps – has fascinated biologists ever since Darwin; how can selection favor a trait that decreases reproductive fitness? The previously accepted answer to this puzzle has recently been challenged, generating much controversy, but a re-evaluation now confirms important insights from kin selection and inclusive fitness, such as the importance of relatedness and the existence of conflicts in social insect colonies. See Liao et al.
Image Credit: Ian Sane, Flickr