Abstract In many mammals, breeding females are intolerant of each other and seldom associate closely but, in some, they aggregate in groups that vary in size, stability, and kinship structure. Aggregation frequently increases competition for food, and interspecific differences in female sociality among mammals are commonly attributed to contrasts in ecological parameters, including variation in activity timing, the distribution of resources, as well as the risk of predation. However, there is increasing indication that differences in female sociality are also associated with phylogenetic relationships and with contrasts in life-history parameters. We show here that evolutionary transitions from systems where breeding females usually occupy separate ranges (“singular breeding”) to systems where breeding females usually aggregate (“plural breeding”) have occurred more frequently in monotocous lineages where females produce single young than in polytocous ones where they produce litters. A likely explanation of this association is that competition between breeding females for resources is reduced where they produce single young and is more intense where they produce litters. Our findings reinforce evidence that variation in life-history parameters plays an important role in shaping the evolution of social behavior.

中文翻译：

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哺乳动物的单调性和多元育种的进化

摘要 在许多哺乳动物中，繁殖中的雌性彼此不宽容，很少密切交往，但在一些哺乳动物中，它们聚集成不同大小、稳定性和亲属结构的群体。聚集经常会增加对食物的竞争，哺乳动物之间雌性社会性的种间差异通常归因于生态参数的差异，包括活动时间、资源分布以及捕食风险的变化。然而，越来越多的迹象表明，女性社会性的差异也与系统发育关系和生活史参数的对比有关。我们在这里展示了从繁殖雌性通常占据不同范围的系统（“单一繁殖”）到繁殖雌性通常聚集（“复数繁殖”）的系统的进化转变，在雌性产生单胎后代的单育谱系中比在多胎谱系中发生得更频繁他们生产垃圾的地方。对这种关联的一个可能解释是，繁殖雌性之间对资源的竞争在它们产生单身幼崽的地方减少，而在产生窝的地方更加激烈。我们的发现强化了证据，即生活史参数的变化在塑造社会行为的演变中起着重要作用。对这种关联的一个可能解释是，繁殖雌性之间对资源的竞争在它们产生单身幼崽的地方减少，而在它们产仔的地方更加激烈。我们的发现强化了证据，即生活史参数的变化在塑造社会行为的演变中起着重要作用。对这种关联的一个可能解释是，繁殖雌性之间对资源的竞争在它们产生单身幼崽的地方减少，而在它们产生窝的地方更加激烈。我们的发现强化了证据，即生活史参数的变化在塑造社会行为的演变中起着重要作用。