Amoebas sacrifice themselves for their kin

Nature has a new article demonstrating kin preference in the social amoeba Dictyostelium purpureum. From EurekAlert:

Recognizing one's own family is a common trait among animals – be they chimpanzees, ground squirrels or paper wasps – and because kin recognition can strongly influence cooperative behaviors it can also significantly impact the social evolution of species.

While scientists have repeatedly documented cases of kin recognition, the Rice study is among the first to document the more sophisticated trait of kin discrimination in a social microorganism.

Nature 442, 881-882(24 August 2006) | doi:10.1038/442881a

Social evolution: Kin preference in a social microbe

Natasha J. Mehdiabadi et al.

Kin recognition helps cooperation to evolve in many animals, but it is uncertain whether microorganisms can also use it to focus altruistic behaviour on relatives. Here we show that the social amoeba Dictyostelium purpureum prefers to form groups with its own kin in situations where some individuals die to assist others. By directing altruism towards kin, D. purpureum should generally avoid the costs of chimaerism experienced by the related D. discoideum

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