Abstract:
Variation in cooperative behavior across mammals is strongly related to the kinship composition of groups. Although the factors affecting average genetic relatedness within groups have been studied, the factors that contribute to the production of different categories of kin remain underexplored. Here, I use a mathematical model to explore the factors that determine the proportion of full siblings, maternal half-siblings, paternal half-siblings, and non-siblings within mammal groups. The results suggest that the production of paternal half-siblings is increased by high male reproductive skew and a female-biased sex ratio, the production of maternal half-siblings is increased by high female reproductive skew and male-biased sex ratio, and that there are two routes to the production of full siblings: either high reproductive skew in both sexes (as seen in cooperatively breeding species) or pair-bond stability within groups of low reproductive skew (as seen in humans). These results broadly correspond to observed variation in sibling composition across mammals.
摘要:
哺乳动物之间合作行为的变化与群体的亲属关系密切相关。尽管已经研究了影响群体内平均遗传相关性的因素,导致不同类别亲属生产的因素仍未充分开发。这里,我使用数学模型来探索决定兄弟姐妹比例的因素,母亲同父异母的兄弟姐妹,同父异母的兄弟姐妹,和哺乳动物群体内的非兄弟姐妹。结果表明,父系同父异母兄弟姐妹的产量因男性高生殖偏斜和女性偏向的性别比例而增加,母亲同父异母的生产增加了高女性生殖偏斜和男性偏见的性别比例,并且有两种方法可以生产完整的兄弟姐妹:两种性别的高生殖偏斜(如在合作繁殖物种中看到的)或低生殖偏斜群体中的配对稳定(如在人类中看到的)。这些结果大致对应于在哺乳动物中观察到的兄弟姐妹组成的变化。