Evolution and humans: all over Africa (Evolution)

by David Turell , Wednesday, May 02, 2018, 23:40 (2395 days ago) @ dhw

DAVID: If a brain is built for more advanced thought by the s/s/c, why not start using it?

dhw: The obvious answer is that the new size was caused by the need for more capacity. Once the brain had expanded sufficiently to implement the new concept (now pre-sapiens could make his spear), there was no further need for change until the next major concept came along. The sapiens brain reached optimal size, and so when new concepts came along, it increased the efficiency of its complexification (so much so that it actually shrank).

That is your theory nad not lboviuos to me.

dhw: I’m sure this is true, but as above, it is you who have constantly asked why there was a long period of stasis and then a sudden burst 12,000 years ago. […]

DAVID: Of course climate was a major factor, but given some more reflection I noted that there were previous good climate periods that were not used, and I noted that the best civilized ideas came from those who migrated north to colder climes. So which climate is best for advanced thinking? It is funny that a new single point you seize upon is a be all and end all for your theory, when lots of other factors need to be considered. Multifactorial is the proper approach.

dhw: It is not the be-all and end-all, and I agree with the reflections you came up with after initially agreeing with the reflections of the researchers. Your point all along has been that there were some 300,000 years of stasis, and then there was a sudden breakthrough. This coincides with a major change in climate. Maybe in earlier periods there were no geniuses around to realize the potential. Do please tell us your own explanation. Once the turning point had come 12,000 years ago, maybe the relatively colder climes created more problems than the warmer climes (e.g. how to keep warm): you need more sophisticated forms of dwelling, which is a not insignificant factor in the advance of civilisation.

Your points are well taken. Sapiens from Africa did face the challenges of a colder climate, but at the time they moved north because they had an advanced brain which could use its s/s/c to solve the problems. It is noteworthy that the earlier hominins did not try the northward movement. I believe at all levels of hominin development there was a delay reaching a level thought/planing to create new artifacts.