Twixt Brain and Tongue

I have been pretty busy of late,   but  I have an urge to say something if only to prove I’m still alive so I thought I’d summarize what I know about the brain’s evolution and language. The main thing we know for an absolute certainty is that the brain suddenly got a lot bigger, about 3.3 times larger than the ape brains of Australopithecus of 2.5 million years ago.Brains are expensive body parts. They put heavy metabolic demands on the system and they do not forgive malnutrition, especially in childhood. So the expansion of   the brain size was only possible if food was reliable throughout the year. There are some possible trade-offs. We can sacrifice other metabolic demands. Chimpanzees and gorillas are much stronger than humans, strong enough to be able to tear humans apart. So we might have sacrificed some serious muscle strength in order to support our brains, but that only works if the ancestors found some substitute for muscle power. Stone tools were part of the kit of the earliestHomo and perhaps there were other wooden and vegetable tools   that did not survive. Fire is another solution. Cooked food provides many more  calories than raw stuff, but when did cooked food come into style? A quarter million years ago? Half a million? A million? A million and a half? There are advocates for each of these answers. I lean toward old dates, but who can say? It seems fairly clear that the brain was already growing when fire came along, but cooked food probably made ...
Source: Babel's Dawn - Category: Speech-Language Pathology Authors: Source Type: blogs