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

by dhw, Thursday, February 01, 2018, 13:58 (2270 days ago) @ David Turell

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.

dhw: 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).

DAVID: The jello-like brain expanded and forced the skull to expand is what this means.

I know what it means. I pointed out that complexification and shrinkage are not the only scientific fact, and the question is why and how the jello-like brain expanded. Your comment is no answer to hypothesis (1).

dhw: 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: God has His own reasons. Thank you for pointing out His actions.

I am explaining the two alternatives. Thank you for confirming that you haven’t got a clue why your God would expand the brain before there was any reason for him to do so. Your own hypothesis doesn’t make sense to you, so back you go to the same old mantra – that God’s reasoning must be different from ours. Why not allow for the possibility that our reasoning might not be different from your God’s, and consider hypothesis (1) which offers a clear reason?

dhw: 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 continuously twist the ideas I present: the expansion of the brain was added cortical complexity for the s/s/c to use in developing the new ideas. Hardware and software.

You continuously try to twist your own analogy. According to you, the cortex does not do the thinking, because you are a dualist and you believe the soul/self/consciousness does the thinking. And so the s/s/c (software) uses the brain (computer) to IMPLEMENT its ideas, not to DEVELOP them.

dhw: 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: No contradiction if you realize the brain is a material computer and the s/s/c is an immaterial operating software.

As above: the software (s/s/c) does the thinking, and so it makes absolutely no sense to say that the computer (brain) had to expand before the software (s/s/c) could think of its new ideas.

DAVID: My antropocentric hypothesis explains everything which is why I propose it.
dhw: 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.
DAVID: You do have a theory that outlines how evolution appears from outside the process. It totally leaves out the obvious appearance of purpose from the standpoint of recognizing God's role.

No it doesn’t. If God exists, and his evolutionary method produced an ever-changing bush of life, it makes perfect sense to suggest that his purpose was to produce an ever-changing bush of life.