Brain expansion (Evolution)

by David Turell @, Sunday, August 16, 2020, 20:10 (43 days ago) @ dhw

DAVID: A mechanism put in the brain by God when He expanded it as sapiens appeared by His design.

dhw: This is a change from your previous agreement that our predecessors would also have had a mechanism for complexification.

My statement doesn't say 'new' mechanism. I've always said previous brains had complexification

DAVID: Took another look at current articles:

I shall only reproduce the most relevant quotes here:

QUOTES: "Researchers measured the endocasts of a variety of Homo sapien specimens, from ancient to modern. The measurements reveal a gradual transition from an elongated endocranial shape to a more globular brain."

"Only fossils younger than 35,000 years feature a globular braincase shape similar to those found among of modern humans."

"The transformation was associated with two cerebral processes, parietal and cerebellar bulging."

"'The gradual evolution of modern human brain shape seems to parallel the gradual emergence of behavioral modernity as seen from the archeological record," (dhw's bolds)

dhw: Wow! This is a real eye-opener! Once again I can only thank you for keeping us abreast of such new scientific discoveries, as well as for your integrity in presenting material that can be used as evidence for a theory you dislike. Bearing in mind that research into the working of the modern brain shows quite clearly that it changes its structure IN RESPONSE to new requirements, you could hardly have a clearer illustration of the process I have been advocating. In this case, since expansion was presumably impractical, it was the shape that changed in order to provide better accommodation for the parietal and cerebellar bulging, which would have been caused by the brain's responses to the new ideas, requirements, patterns of behaviour that mark our modern age. (NB These changes were gradual - obviously because each new requirement would demand a new change - it didn't all happen at once). Or are you now going to tell us that in addition to operating on the Moroccans 315,000 years ago, your God stepped in 35,000 years ago to do a rounding operation in advance of the behavioural changes? Once more: if the modern brain changes IN RESPONSE to new requirements, why should we not assume that the same process would have caused the expansion of earlier brains?

DAVID: We know the brain case and brain shrunk by 150 cc from about 35,000 years ago. We know the complexification mechanism the brain was given reorganized the existing brain regions, slightly enlarging some highly used areas and discarding others as unnecessary, as we learned how to use it completely. That is all we know as facts.

dhw: Yes indeed, except that this article also tells us that the modern brain gradually changed its shape to accommodate parietal and cerebellar bulging. Do you think your God stepped in to do the bulging before sapiens came up with his modern ideas, or do you think it was implementation of the ideas that caused the bulging? I am opting decisively for the latter. And I am proposing that if new behaviour, ideas, requirements can cause the brain to change its shape, to complexify, to expand in certain areas, the same process may explain the expansion of earlier brains.

The changing brain shape is certainly due to complexification. The bony shape change is due in part to simple adaptation. The infant and child skull plates are soft and held together by fibrous material with fusion occurring in late adolescence. God not involved.

DAVID: I'm happy to present the material which can then be interpreted by your natural expansion theory and my designed by God theory. You can try all you want to extrapolate your theory from our brain, but it came very enlarged to begin with, prepared for the future changes we see. It does not tell us how it enlarged. I believe God enlarged it, knowing how we would learn to use it.

dhw: Again, I am grateful for your fair-mindedness in presenting material so helpful to my own proposal. All the “new” brains of our ancestors were “enlarged to begin with”, but we agree that nobody knows how or why their brains and ours became enlarged. That is why we have our theories.

Thank you.

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