Brain expansion (Evolution)

by dhw, Sunday, August 02, 2020, 07:23 (1572 days ago) @ David Turell

DAVID: It was clear in that post that advanced stone tools predated Moroccan sapiens. The true confusion is no homo fossils to tell us who thought of it. No support for your theory a bright idea drives expansion to a new brain, which is why you have perfunctorily sloughed off the post.

dhw: I didn’t slough it off! On the contrary I presented it because it squashed your effort to use the Moroccans as evidence against my theory![…]. None of these articles provide the slightest support for your theory that one night God stepped in and dabbled with the brains, skulls and pelvises of a few Moroccans! Does that lead you to reject it?

DAVID: Note this article shows in tool making in a lesser brain by H. habilis:
https://science.sciencemag.org/content/369/6503/520.4?utm_campaign=ec_sci_2020-07-30&am...

QUOTE: A very rare type of tool made from a hippopotamus bone has been discovered at the Konso Formation in southern Ethiopia. This artifact represents a technological breakthrough achieved 1.75 million years ago.BB […] (David’s bold)

The article goes on to explain all the features that were original, and attributes the tool to homo erectus, not habilis.

DAVID: The Moroccan tools were not that advanced in comparison. Itty-bitty advances until very recently. The tools did not drive expansion. […]

Then maybe it was these tools that required the expansion of the erectus brain. But I don’t know why you are fixated on tools. We took the spear as a concrete example of the process, but NOBODY KNOWS what caused expansion. 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: (on “Our unusual cerebellum”): This adds more to the amazing expansion of the sapiens brain. Unfortunately we cannot study pre-sapiens cerabellums to understand the evolution, but its ties to the expanded cerebrum could be newly arrived to aide in cognition and abstractions.

dhw: I’d be happy with “newly expanded cerebrum” rather than “expanded cerebrum newly arrived”. A dualist, in my view, would have to argue that all the complexifications and expansions were in RESPONSE to the soul’s new ideas. A materialist would argue that they caused the new ideas.

DAVID: You are not my dualist, as my dualism is so different, as you well know.

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: (on “Astrocytes drove enlargements"): Our big brain is astroglial driven. "Due to an exaptation". Wow!: exaptations are unexpected changes in function of that which previously existed with a different function. As if God stepped in and added His design. . It certainly was 'punctuated equilibrium', although not in the true Gouldian sense.

dhw: Since there was a long period of stasis before, presumably, different parts of the brain changed their functions, and there were also long periods of stasis between earlier expansions, I reckon “punctuated equilibrium” is a good description. I don’t know why your God would have had to step in, since you have already agreed that complexification is an autonomous process. I would suggest that [...] intelligent cells (we shouldn’t forget that astrocytes are cells) cooperated in adapting themselves to perform whatever functions were required of them.

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

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

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: Habilis brain was used quite actively, as was the erectus larger brain, and then sapiens appeared, with not much different in lifestyle until 70,000 years ago. So 'big' ideas driving expansion has no sense of proof in the facts we have. Our enormous ideas caused shrinkage from complexification.

What is a “sense of proof”? NOBODY KNOWS WHAT CAUSED EXPANSION, and the sapiens stasis does not provide any “sense of proof” that your God did an overnight dabble on a group of Moroccans. But yes, our enormous ideas caused shrinkage from complexification, thus proving that the implementation of ideas changes the brain.