一项研究提出，一个雄性和一个雌性配对交配并抚养后代的社会单偶制可能是为了减少雄性杀婴的威胁而从灵长类动物中进化出来的。在哺乳动物中，单偶制是罕见的，而且促进了它的进化的原因仍不清楚。Christopher Opie及其同事使用统计模型评估了3种竞争的假说，科学家提出这些假说用于解释单偶制的进化。它们分别是：雄性和一个雌性配对从而阻止该雌性与雄性的对手交配，因此也就改善了他的繁殖机会；父亲对照顾后代的贡献提高了一对配偶的繁殖成功机率；或者配对的雄性保护了他的后代不受其他雄性伤害，后者可能杀死没有亲缘关系的婴儿从而改善它们与这些婴儿的母亲繁殖后代的机会。这组作者使用来自230个灵长类物种的特征数据检验了单偶制进化与每一种假说的一个标记特征之间的关系，这些特征分别是：雌性范围模式，父亲的照顾以及雄性杀婴。这组作者发现，每一种特征都与单偶制共同进化，但是只有雄性杀婴在配偶生活出现之前出现。这组作者说，这些发现提示单偶制可能由于雄性杀婴的威胁而从灵长类动物中进化出来的，而且一旦建立起来，配偶生活可能促进了配偶保护和父亲照顾的出现。（生物谷Bioon.com）
生物谷推荐的英文摘要
PNAS doi: 10.1073/pnas.1307903110
Male infanticide leads to social monogamy in primates
Christopher Opiea,1, Quentin D. Atkinsonb, Robin I. M. Dunbarc, and Susanne Shultzd
Although common in birds, social monogamy, or pair-living, is rare among mammals because internal gestation and lactation in mammals makes it advantageous for males to seek additional mating opportunities. A number of hypotheses have been proposed to explain the evolution of social monogamy among mammals: as a male mate-guarding strategy, because of the benefits of biparental care, or as a defense against infanticidal males. However, comparative analyses have been unable to resolve the root causes of monogamy. Primates are unusual among mammals because monogamy has evolved independently in all of the major clades. Here we combine trait data across 230 primate species with a Bayesian likelihood framework to test for correlated evolution between monogamy and a range of traits to evaluate the competing hypotheses. We find evidence of correlated evolution between social monogamy and both female ranging patterns and biparental care, but the most compelling explanation for the appearance of monogamy is male infanticide. It is only the presence of infanticide that reliably increases the probability of a shift to social monogamy, whereas monogamy allows the secondary adoption of paternal care and is associated with a shift to discrete ranges. The origin of social monogamy in primates is best explained by long lactation periods caused by altriciality, making primate infants particularly vulnerable to infanticidal males. We show that biparental care shortens relative lactation length, thereby reducing infanticide risk and increasing reproductive rates. These phylogenetic analyses support a key role for infanticide in the social evolution of primates, and potentially, humans.
