Evolution and humans: more on learning to read (Evolution)

by dhw, Saturday, November 10, 2018, 13:58 (9 days ago) @ David Turell

DAVID: You stay blind to the fact that a big brain appeared before all the new concepts were developed.

dhw: As you well know, pre-sapiens brains gradually increased in size, and I’m sorry, but the H. sapiens brain (if that’s what you mean by a “big brain”) did not appear before such new concepts as tools, weapons, use of fire etc.

DAVID: You have forgotten that the fossils we have show the brain size jumped 200 cc at a time with each new homo ancestor. You're back to your Darwinism looking for itty -bitty changes.

dhw: I am offering an explanation for WHY the brain size jumped! (I used "gradually" because there were so many phases.) Namely, that new concepts “exercised” the brain - exercise was the word used in the article - to a degree that exceeded the existing capacity. Consequently the brain and its container had to expand.

DAVID: Yours is a non-answer: so many phases refers to 200 cc jumps in size in the fossils we have from 400 cc to 1,200 cc. I count four 'phases'. Why did human skulls expand while apes did not? New concepts did not drive expansion; they appeared because of the ability to create concepts with a bigger more complex brain.

We know that exercise, in the form of implementing new concepts, changes the sapiens brain, even to the extent of expanding certain sections of it, and so I don’t know why you think it is a non-answer to propose that exercise, in the form of implementation of new concepts, also changed the brain, even to the extent of expansion, in the past. I suggest that apes stayed as they were because they did not have the new concepts which required expansion of the brain. The split between apes and pre-humans may have occurred when, for whatever reason, a particular group or groups descended from the trees. This entailed a new way of life, which inevitably would have entailed new concepts, and hence changes to the brain. You seem to think that because some apes left the trees, all apes should have left the trees. Once the brain had expanded, yes, it may well have come up with more new concepts before these in turn required greater capacity and so on until the brain reached its optimum size in sapiens, and then complexification took over.


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