Sex-linked altruism.
D000818:Animals; D005075:Biological Evolution; D001717:Birds; D005260:Female; D005796:Genes; D007313:Insecta; D008297:Male; D008322:Mammals; D012104:Reptiles; D012730:Sex Chromosomes / Q000502:physiology*; D012801:Sibling Relations; D012919:Social Behavior