Subsequently, the underlying trend towards increasing brain
size in Homo is most strongly correlated with both
decreases in lake presence and high levels of dust deposition
in the Mediterranean ODP967 record (Table 3), indicating drier conditions
in East Africa [43].
The retreat has been most noticeable at high elevations, driven
in large part by warming temperatures contributing directly to melting and indirectly to more precipitation falling as rain rather than snow,
in turn increasing the rate at which the glaciers move and increasing the
size of glacial
lakes, both
decreasing ice cover.