Evolution and humans: all over Africa (Evolution)

by dhw, Friday, May 04, 2018, 12:34 (2393 days ago) @ David Turell

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).
DAVID: That is your theory and not obvious to me.

dhw: Then please give us your own explanation for the sapiens “gap” of 300,000 years, and the hundreds of thousands of years “gap” during which hominins’ brain size and way of life also remained static.
DAVID: As before, God speciates and creates a 'next' species with more pre-frontal, frontal size and complexity. It then takes time to learn how to use the new size. The contemporary artifacts prove the point.

Please enlighten me. Did the artefacts appear when the new species appeared, or was there a sapiens-like “gap” BEFORE the artefacts appeared? If nothing new happens for hundreds of thousands of years after the arrival of the new brain, please tell us what uses of the new brain are being “learned”, and how do you think the “learning” takes place if it produces nothing?

DAVID: Survival skills are limited in brain requirements, since the lifestyle is so simple. Only the current sapiens brain could have created our very complex civilization, which has erupted in the past few hundred years. And the brain shrunk by 150cc, when your proposal of a conceptual demand for explosion seams to ask for more results earlier.

All agreed except that my proposal does no such thing. It EXPLAINS why there are long periods of stasis: new concept (e.g. spear) realized, no need for further expansion until next genius comes up with next major concept. Invention comes through special minds. But it may be triggered by opportunities offered by environmental change, as proposed in the article. I keep suggesting that shrinkage was due to the efficiency of complexification, and I thought you agreed.

dhw: We know there was a “delay” or “gap” at all levels, including sapiens. I have offered you an explanation above. Please point out any logical flaws in this hypothesis and give us your own explanation for the gaps at all levels.
DAVID: Second request for same answer as above. Remember God starts it. You seek a natural chance mechanism a 'la Darwin to explode brains. And you answer God might have doesn't get around my objection.

If there is a God, he will certainly have started it. But instead of starting it by dabbling with somebody’s brain, he could have started it by giving all brains the ability to complexify and/or expand in response to the activities of the s/s/c (regardless of its source). There is no chance mechanism if your God created it, this has nothing to do with Darwin, and it seems that the only “logical flaw” you can find is that my theistic hypothesis is not yours.