No evidence that hominin dispersal across Eurasia was part of a wider turnover in mammal distributions

The drivers and consequences of hominin dispersals out of Africa remain debated. The spatial and temporal distribution of large mammal faunas contemporaneous with early Homo provides direct evidence for their ecological context and impact. In this study, we conduct taxonomic and functional similarity analyses on fossil and extant Eurasian and African large mammal communities of the last 10 Ma. We test two hypotheses: 1) the dispersal of hominins across Eurasia around or shortly after ~2 Ma was part of a wave of faunal dispersals out of Africa; 2) the arrival of hominins at Eurasian sites coincided with major changes in the functional structure of large mammal communities. Our results indicate that hominin dispersals from Africa to Eurasia during the Plio-Pleistocene were not part of a larger faunal expansion. Instead, the most significant faunal interchange during the Plio-Pleistocene occurred between Europe and Asia, while African faunas have mostly remained distinct from Eurasian faunas since ~7 Ma. Our results suggest relative homogeneity in community functional structure across Eurasia and Africa since at least 10 Ma. In contrast to fossil communities, modern Eurasian and African terrestrial large mammal faunas show strong geographic functional structure, which might reflect the selectivity of Late Pleistocene extinctions.