"The Baldwinian perspective suggests...
that the first stone tools were manufactured by australopithecines, and that the transition to Homo was
in part a consequence rather than the cause.... The large brains, stone tools, reduction in dentition,
better opposability of thumb and fingers, and more complete bipedality found in post-australopithecine hominids are the physical echoes of a threshold already crossed [in behavior]....
Another way to look at this is to say that many of the physical traits that distinguish modern human
bodies and brains were ultimately caused by ideas shared down the generations."