Ungulates (antelopes, deer and relatives) have some of the most diverse social systems among mammals. To understand the evolution of ungulate social organization, Jarman (1974) proposed an ecological scenario of how distribution of resources, habitat and feeding style may have influenced social organization. Although Jarman's scenario makes intuitive sense and remains a textbook example of social evolution, it has not been scrutinized using modern phylogenetic comparative methods. Here we use 230 ungulate species from ten families to test Jarman's hypotheses using phylogenetic analyses. Consistent with Jarman's proposition, both habitat and feeding style predict group size, since grazing ungulates typically live in open habitats and form large herds. Group size, in turn, has a knock-on effect on mating systems and sexual size dimorphism, since ungulates that live in large herds exhibit polygamy and extensive sexual size dimorphism. Phylogenetic confirmatory path analyses suggest that evolutionary changes in habitat type, feeding style and body size directly (or indirectly) induce shifts in social organization. Taken together, these phylogenetic comparative analyses confirm Jarman's conjectures, although they also uncover novel relationships between ecology and social organization. Further studies are needed to explore the relevance of Jarman (1974) scenario for mammals beyond ungulates.

中文翻译：

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有蹄类动物的社会组织：重温贾曼的假设。

有蹄类动物（羚羊、鹿和亲戚）在哺乳动物中拥有一些最多样化的社会系统。为了了解有蹄类动物社会组织的演变，Jarman (1974) 提出了一个生态情景，说明资源分布、栖息地和进食方式可能如何影响社会组织。尽管贾曼的情景具有直观的意义并且仍然是社会进化的教科书示例，但尚未使用现代系统发育比较方法对其进行仔细审查。在这里，我们使用来自 10 个科的 230 种有蹄类动物通过系统发育分析来检验 Jarman 的假设。与 Jarman 的主张一致，栖息地和进食方式都可以预测群体规模，因为放牧有蹄类动物通常生活在开阔的栖息地并形成大群。反过来，团体规模 对交配系统和性别大小二态性有连锁反应，因为生活在大群中的有蹄类动物表现出一夫多妻制和广泛的性别大小二态性。系统发育验证路径分析表明，栖息地类型、进食方式和体型的进化变化直接（或间接）导致社会组织的变化。总之，这些系统发育比较分析证实了贾曼的猜想，尽管它们也揭示了生态学和社会组织之间的新关系。需要进一步的研究来探索 Jarman (1974) 情景对有蹄类动物以外的哺乳动物的相关性。喂养方式和体型直接（或间接）导致社会组织的变化。总之，这些系统发育比较分析证实了贾曼的猜想，尽管它们也揭示了生态学和社会组织之间的新关系。需要进一步的研究来探索 Jarman (1974) 情景对有蹄类动物以外的哺乳动物的相关性。喂养方式和体型直接（或间接）导致社会组织的变化。总之，这些系统发育比较分析证实了贾曼的猜想，尽管它们也揭示了生态学和社会组织之间的新关系。需要进一步的研究来探索 Jarman (1974) 情景对有蹄类动物以外的哺乳动物的相关性。