Brain expansion (Evolution)

by dhw, Friday, July 24, 2020, 11:33 (1365 days ago) @ David Turell

DAVID: I realize that implementation requires design and planning and then production, and in my view requires a more complex brain to allow the soul to do that implementation.

dhw: Agreed. And I propose that it is the process of implementation of new ideas and requirements that causes the modern brain to be more complex, and earlier caused it to expand, whereas you presumably agree that implementation causes the modern brain to be more complex, but you propose that in earlier times your God had to step in and dabble the expansion BEFORE the dualist’s soul could come up with new ideas and requirements.

DAVID: The bold is not a correct interpretation of my view. The larger-than-needed brain allowed us to tailor the already given complexity to our preferred uses of the brain. But certainly, implementation of new ideas, developed by that complex brain, played a large role in the process.

This is not a rebuttal of the bold! Do you or do you not agree that the modern brain complexifies when implementing new requirements? Our subject here is why the earlier brain expanded. The modern brain complexifies in response to requirements and even performs minor expansions. I argue that the same process may have been in action before sapiens, though in those times the brain needed greater capacity to cope with requirements, and so it was the mechanism for expansion that came into operation. You argue that the brain expanded BEFORE there were any new requirements. On shrinkage, see below.
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On the subject of why David’s God gave us 150 cc extra brain which we did not need and which therefore disappeared after approx. 270,000 years, resulting in brain shrinkage:

DAVID: I'll repeat., again: To allow us to use the brain as we wished so that the eventual brain would exactly fit our uses.

dhw: So God gave us what we needed plus 150cc extra. We didn’t use the extra (270,000 years of stasis) but it “allowed” us to think what we wanted to think. Perhaps I shouldn’t ask you how our not using it “allowed” thoughts we didn’t have, or thoughts we did have after 270,000 years, when it still wasn’t used and therefore disappeared. Perhaps I should just leave you to think what you want to think.

DAVID: Your-tongue-in-cheek description gets it!!! New ideas took a long time to appear. The first sapiens were pretty sluggish thinkers, but they finally got the hang of it, but from the beginning they were way beyond apes.

Of course human brains were beyond apes, even before sapiens arrived! And we agree that after the initial expansion to sapiens size, there were no new ideas, and so there was a period of stasis. How does that explain why your God gave us 150 cc more brain than we needed so that we could think thoughts we didn’t think, and when we did think the new thoughts, the 150 cc were still useless, so they disappeared?