Brain expansion (Evolution)

by dhw, Monday, August 03, 2020, 13:04 (1571 days ago) @ David Turell

dhw: My theory is not based on tools but on the fact that the modern brain responds to new requirements by complexifying or, on a small scale, expanding, and I see no reason why the same process should not have taken place in earlier brains, but with major expansions. You have not yet provided any reason why it shouldn’t.

DAVID: Yes I have. I think God expanded brains and that explains the progression of better artifacts with each new-size brain.

As on the “abstract thinking” thread, your opinion apparently provides a reason why my opinion must be wrong! But we agree that better artefacts go together with new-size brains. They may even be the cause of new-size brains, since we know brains change in the process of meeting new requirements. We disagree on your insistence that your God must have expanded brains before homos could come up with any new concepts.

dhw: You have often said that the brain causes thought, but when challenged you have claimed that I have misunderstood your shorthand. Do you now disagree that the dualist's brain DOES NOT CAUSE thoughts but complexifies/expands in RESPONSE to the thoughts of the dualist's soul? Please answer without equivocation.

DAVID; As usual, as you well know my theory, the soul must use the existing brain complexity to develop the allowed degree of thought complexity.

And there was me hoping for an unequivocal yes or no! What is the “allowed” degree of thought complexity? I’ll try again. Do you believe (a) that the dualist’s soul cannot think of new concepts until his brain has already undergone new complexifications/expansions, or (b) that the soul thinks of new concepts using the existing brain, and this then undergoes complexification/expansion in the process of developing and implementing the new concept? A clear choice for you.

DAVID: 'Stasis', as we use the term, occurs after enlargement, not before…

dhw: Stasis occurs before and after enlargement! Here is my sequence: 1) new requirement, 2) brain enlarges through meeting new requirement; 3) followed by stasis = no new ideas, no expansion. 4) Stasis ends with new ideas and new expansion. When I say “long periods of stasis between earlier expansions”, the stasis comes after the original enlargement and before the next one! Sapiens' stasis came between initial expansion and sudden burst of new ideas, resulting in enhanced complexification.

DAVID: Sapiens history of stasis does not fit your definition of stasis. Moroccans did not show new artifacts in the discovery of sapiens fossils.

I keep pointing out that NOBODY KNOWS the causes of expansion, and I asked why you were so fixated on artefacts as the only possible cause. My definition of stasis is a period during which there are no changes. We don’t know what caused Moroccan enlargement, but we do know there were no changes for approx. 270,000 years, which = stasis. Now please tell me your definition of stasis, and why my definition does not fit the history.

DAVID....and complexification is after enlargement and then the brain reorganizes to fit the soul's uses.

dhw: Complexification, as we have agreed, would have preceded all enlargements and followed all enlargements. In sapiens, however, major enlargement ceased and complexification took over. If by “reorganizes” you mean the brain complexifies as it implements the thoughts of the dualist’s soul, we are in agreement.

DAVID: No, I mean our brain was over-enlarged and then shrunk as reorganized to fit our uses. Whether habilis or erectus complexified is likely, but not proven because of what fossils give us to know.

What do you mean by “reorganized” if you DON’T mean the brain complexified? What other form of change was there, apart from minor expansions? We agree that pre-sapiens brains were likely to have complexified as well as expanded.

DAVID: All we can know is a bigger brain can shrink under usage. I'll stick with God running evolution as we know it.

We have agreed that it shrank because the excess was not needed thanks to the efficiency of complexification. We also know that the bigger brain changes IN RESPONSE to new requirements. Why do you keep ignoring this proven fact? And why do you assume that the same process could not have applied to pre-sapiens expansion? And why do you keep harping on about “God running evolution”, as if your God could not possibly have run evolution by designing a mechanism that enabled the brain to expand as well as to complexify without his intervention? After all, on the “errors” thread, you have him designing a system in which the molecules “ARE FREE TO MAKE MISTAKES” and some of those “mistakes” are BENEFICIAL, even to the point at which they may have “arranged for our human evolution”. Let’s call them mutations so that we can avoid the bad implications of “mistakes” and “errors”. Then we have a perfectly logical, theistic explanation for the history of evolution as we know it, all the way from single cells via the great higgledy-piggledy bush of comings and goings to humans and their brain expansions. See under “Back to David’s theory of evolution” for the logical theistic choice that is then open to you.