In 2010 three authors—Martin Nowak, Corina Tarnita, and E. O. Wilson—published a paper in Nature (reference and link below) purporting to explain the evolution of eusociality in insects: the phenomenon whereby a colony contains different “castes” that perform different tasks, and at least one caste is sterile. In bees, for example, there is usually a single fertile queen, who produces all the offspring, a bunch of sterile working females (“workers”) who defend the nest and tend the brood, and fertile male “drones” who do basically nothing but compete to mate with the next generation of queens. Nonreproductive castes are general (though not ubiquitious) in the Hymenoptera (ants and wasps), as well as in some other animals like termites (Isoptera) and naked mole rats.
It’s hard to understand how it could be advantageous for some individuals to evolve sterility, which, of course, seems patently maladaptive. Darwin was the first to notice this problem. At any rate, one solution involves the notion of kin selection: the idea that a gene can promote sacrificing your own personal reproduction if it more than compensates for that loss by increasing the number of relatives you have—relatives who also carry copies of the “sacrifice” gene. It turns out that under a simple calculus that involves weighing the reprodutive benefit to relatives (discounted by the degree of relatedness) versus the cost of sacrificing your own reproduction, you can indeed evolve genes that cause you to lose reproductive ability—so long as they increase it in your relatives.
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Read full, original article: New paper shows that Nowak et al. were wrong: kin selection remains a valuable concept in evolutionary biology
