CORRECTION

PRIMATES WALKING:
In my previous posting, I indicated that our evolutionary ancestors had been walking and using tools over the period of the last ice age (125,000 years). It seems walking has been going on, so far as can be inferred from the development of a heel that can support full body weight, at the beginning of the ice ages, some 2.5 million years ago! There is evidence of tool using from that time also. However, primate brains were much smaller then. At the beginning of the most recent ice age, hominid brains had increased 300% in size and the newer brain part, the cerebral cortex, had become much larger and elaborated.