Some hominins may have preferred to live in shady glades near fresh water nearly 2 million years ago.

Clayton Magill at the Swiss Federal Institute of Technology in Zurich and his colleagues took samples from a layer of soil in Olduvai Gorge, Tanzania, where fossil remains for early Homo and Paranthropus boisei hominins have been found. This 1.8-million-year-old soil was covered by a layer of volcanic ash, which preserved the distinctive chemical signatures left behind by ancient plants. By analysing these 'biomarkers', the team was able to distinguish aquatic from terrestrial plants, grasses from non-grasses, and woody plants from herbaceous ones.

The biomarker analysis and fossil remains suggest that the hominins favoured a small wooded area near a freshwater wetland, presumably because it offered drinking water, edible plants and shade. The presence of fossilized butchered animal remains also implies that the hominins brought food back to their woodland home from the larger grassland area.

Proc. Natl Acad. Sci. USA http://dx.doi.org/10.1073/pnas.1507055113 (2016)