"Sunset on the Savanna" by James Shreeve

Summary Paper
Sunset on the Savanna
"Why do we walk? For decades anthropologists said that we became bipedal
to survive on the African savanna. But a slew of new fossils have destroyed that
appealing notion and left researchers groping for a new paradigm."
Sunset on the Savanna, James Shreeve, Discover, July 1996, pp.116-125.
It has generally been thought that it was the shift from life in the forest to life in an open habitat that set the ape apart by forcing it to walk on two legs. More simply stated, we learned to walk by moving from the trees to living on the grasslands. …