The study highlights the important role of kin selection in evolution, where organisms are more inclined to favour others to the extent to which they are genetically related. (sciencedaily.com)
(The geneticist J.B.S. Haldane, who explored early concepts of kin selection in the 1930s, is sometimes alleged to have joked that, as a human being, he would lay down his life for two brothers or eight cousins.) (quantamagazine.org)
To see how this so - called kin selection theory might apply to adoptive parents, researchers compared data on 135 pairs of «virtual twins» — siblings about the same age consisting of either one adopted child and one biological child or two adopted children. (sciencemag.org)