Big brain evolution: changes in sapiens skull shape (Evolution)

by dhw, Wednesday, January 31, 2018, 14:04 (1004 days ago) @ David Turell

dhw: More complex artefacts may be implemented by the process of the brain complexifying, but in the case of pre-sapiens, when the capacity for complexification had reached its limit, more cells and connections were needed to implement the concept, and so the process of implementation resulted in expansion. The implement could not appear until this process was complete. (My bold)

DAVID: Except the only scientific fact we have is the brain shrinks with complexification. Very few new neurons are added and complex branching can occur within less space, not more, creating the shrinkage.

I thought it was a scientific fact that hominid/hominin brains expanded, and we are discussing why and how. Here are two hypotheses based on the dualistic belief that concepts are produced by the soul and not the brain: 1) the number of then existing pre-sapiens neurons and connections eventually proved inadequate to perform the actions required to implement new concepts - hence more neurons and connections (= expansion through implementation). 2) God added more neurons and connections BEFORE the souls of hominids/hominins thought up the new concepts that needed to be implemented (= expansion for no reason).

DAVID: My point is you cannot know what happened inside pre-sapiens brains. The new complexity more than likely shrunk the brain, since evolution builds on established processes.

Nobody knows, and that is why we have different hypotheses. If pre-sapiens brains were able to cope with ALL concepts by complexifying and shrinking, there would have been no need for expansion, with or without your God’s dabbles! Obviously, then pre-sapiens complexification, and the shrinkage you also insist on, were NOT adequate. Since you believe the brain does not think up concepts, quite clearly the expansion of the brain was not necessary for thinking up new concepts!

DAVID: You've misgotten it! Complexification shrinks the brain, is the only evidence we have!
dhw: Again you are dodging from pre-sapiens to sapiens. We know that pre-sapiens brain expanded! That means it added new cells and connections, precisely as explained above!
DAVID: Wonderful. You know that as fact that new implementations forced an enlargement? Your 'push' theory has no basis in existing scientific fact.

It’s a hypothesis not a fact. Your ‘pull’ theory has no basis in existing scientific fact, and it also contradicts itself, because it states that hominids/hominins could not have had their new concepts until the brain had enlarged, although according to you, thought is the product of the soul and not of the brain.

DAVID: My antropocentric hypothesis explains everything wich is why I propose it.

I shan't repeat the list of things it doesn't explain. I asked you what part of evolutionary history is not explained by my hypothesis. You still haven’t answered.

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