Pliocene climatic change and the origins of Homo at Ledi-Geraru, Ethiopia

Long-term cooling and aridification are associated with the spread of grassland habitats and the appearance of new hominin adaptations starting in the late Miocene. However, limited fossil data during critical periods limits our ability to examine these climatic correlations further. We set out to reconstruct potential habitat and climate conditions at the origin of our genus Homo. Mammalian faunal lists and species trait data were collected for Ledi-Geraru localities dated from ∼2.78 to Homo at ∼2.78 Ma. Early Homo is associated with ongoing aridification and increasing seasonality in the Afar Depression. While climate trends in eastern Africa parallel global models, local environmental variation persisted across fossil-bearing regions. Climatic change (aridification and increasing seasonality) continues to be supported as a possible factor in the origins of our genus, although other fossil hominins continued to persist in these conditions.

晚中新世以来，长期降温与干旱化趋势与草原生境的扩张以及新的古人类（hominin）适应性特征的出现密切相关。然而，关键时段的化石数据较为匮乏，限制了我们对这类气候相关性开展进一步研究的能力。本研究旨在重建人属（Homo）起源阶段的潜在生境与气候条件。我们收集了年代范围介于约2.78至约2.78百万年前（Ma）的莱迪-加拉鲁（Ledi-Geraru）各遗址的哺乳动物群名录与物种特征数据。阿法盆地（Afar Depression）内的早期人属与持续的干旱化及日益增强的季节性气候显著相关。尽管东非的气候演变趋势与全球气候模型的预测基本一致，但含化石区域仍存在持续的局部环境异质性。尽管其他古人类类群仍在这类环境中持续存续，但气候变化（干旱化与季节性增强）仍被视作驱动人属起源的潜在影响因素之一。