inclusive fitness
the reproductive success not only of an individual but also of all of that individual’s relatives in proportion to their coefficient of relatedness. In calculating estimates of reproductive success, it is assumed that parents, offspring, and siblings have an average of 50% of their genes in common; that grandparents and grand-offspring, as well as uncles or aunts and nieces or nephews, share 25% of genes; and that first cousins share 12.5% of genes.