When Richard Potts, an expert in ancient environments, reviewed evidence about the environment in which Ardipithecus ramidus would have lived at Aramis and Gona, he concluded that the sites:.

The sites indicated variability in the proportion of grass versus trees

Explanation:Ardipithecus ramidus is a hominin species dating to between 4.5 and 4.2 million years ago (mya) using paleomagnetic and radioisotopic dating methods. (Paleomagnetic uses periodic reversals in the Earth’s magnetic field; radioisotopic utilizes the known rate of decay of one radioisotope into another) Importantly, Ar. ramidus represents the oldest species that possesses features unequivocally linked to the hominin lineage. Thus, Ar. ramidus is the best evidence discovered thus far for the root of the hominin family tree. Fossils of this species, found in the Middle Awash region and the site of Gona in Ethiopia, possess derived features (features different from those found in the ancestor) in the skull and teeth.