Department of Anthropology, University of Michigan, Ann Arbor, MI 48109, USA.
Museum of Paleontology, University of Michigan, Ann Arbor, MI 48109, USA.
Science. 2023 Apr 14;380(6641):eabq2835. doi: 10.1126/science.abq2835.
Living hominoids are distinguished by upright torsos and versatile locomotion. It is hypothesized that these features evolved for feeding on fruit from terminal branches in forests. To investigate the evolutionary context of hominoid adaptive origins, we analyzed multiple paleoenvironmental proxies in conjunction with hominoid fossils from the Moroto II site in Uganda. The data indicate seasonally dry woodlands with the earliest evidence of abundant C grasses in Africa based on a confirmed age of 21 million years ago (Ma). We demonstrate that the leaf-eating hominoid consumed water-stressed vegetation, and postcrania from the site indicate ape-like locomotor adaptations. These findings suggest that the origin of hominoid locomotor versatility is associated with foraging on leaves in heterogeneous, open woodlands rather than forests.
现生的人科动物以笔直的躯干和多样的运动方式为特征。人们假设这些特征是为了从森林中树梢末端的果实进化而来的。为了研究人科动物适应性起源的进化背景，我们分析了乌干达莫罗托二世遗址的人科动物化石与多种古环境替代指标。数据表明，这里是季节性干旱的林地，是基于 2100 万年前的一个已确认的年龄，非洲最早有丰富的 C 类草的证据。我们证明了食叶的人科动物消耗了受水分胁迫的植被，而且该遗址的后肢骨骼表明了类似猿的运动适应。这些发现表明，人科动物运动方式的多样性起源与在异质开阔的林地而不是森林中觅食树叶有关。
