Out of Africa

Today's view of human evolution is rapidly shifting from the now-defunct Savannah Hypothesis to the more believable coastal living scenario. No longer is the idea that we developed our brains while hunting on the savannah held true. Some have opted for a semi-woodland environment, but this, too, is leading us to coastal living as the preeminent ecosystem where we evolved from a small-brained biped into a large-brained one. Picture, if you will, a group of LCAs (Last Common Ancestor) living on the east coast of Africa, blocked to the west by the Ethiopian Escarpment, and to the east by the Red Sea. There is plenty of freshwater. We know this because there is a continuum of freshwater springs in this area today, produced by the movement in the East African Rift System. Seafood was plentiful. Even the old and the very young had all they could eat. There was volcanism and rift movement and occasionally openings in the rift would come about and some would leave this paradise for the interior. They may have gotten lost out in this different world and been unable to make their way back. Or, the pathway they took out of their normal environment may have been closed off by rift activity. Unless you think bipedal forms of hominids sprung up spontaneously all over Africa, this is the only interpretation. The likelihood of that is remote when you consider the extremely different environments in which this adaptation would have had to occur.