Human adaptation to diverse biomes over the past 3 million years

To investigate the role of vegetation and ecosystem diversity on hominin adaptation and migration, we identify past human habitat preferences over time using a transient 3-million-year earth system-biome model simulation and an extensive hominin fossil and archaeological database. Our analysis shows that early African hominins predominantly lived in open environments such as grassland and dry shrubland. Migrating into Eurasia, hominins adapted to a broader range of biomes over time. By linking the location and age of hominin sites with corresponding simulated regional biomes, we also find that our ancestors actively selected for spatially diverse environments. The quantitative results lead to a new diversity hypothesis: Homo species, in particular Homo sapiens, were specially equipped to adapt to landscape mosaics. Early humans and their hominin relatives had to adapt to new environments to spread out of Africa. Zeller et al. explored the movements of hominins across and preferences for different biomes by comparing six Homo species distributions from the fossil record against simulated climate and vegetation over the past 3 million years. They found that some later species inhabited a broader range of biomes as they spread to colder and more forested areas, especially H. sapiens, which settled in more extreme habitats (deserts and tundra). In addition to adapting to changing environmental conditions over time, models suggest that Homo species may have preferentially selected areas with more diverse habitats. ?Bianca Lopez Earth system modeling shows how Pleistocene hominins spread across and selected different habitats.