Brain complexity: more important than size (Introduction)

by dhw, Saturday, November 25, 2017, 08:54 (2556 days ago) @ David Turell

dhw: […] I suspect that the brains of our fellow animals do not go beyond improving their chances of survival, and in each case complexification can cope when the brain has reached its optimum size.

DAVID: This comment of yours recognizes the difference in human and animal brains. We all have the same basis sensory and survival parts, some of which are completely automatic. They occupy the hind brain, the mid brain, the cerebellum, the hypothalamus, etc.

Nothing to disagree with here.

dhw: But pre-sapiens devised ever more complex ways of surviving (e.g. increasingly sophisticated tools and weapons, clothing, use of fire, social cohesion) which involved new tasks that required new skills which in turn required new cells to fulfil those tasks.

DAVID: This resulted from the development of a larger frontal and pre-frontal cortex, ever larger with each jump of 200cc in size. The other parts basically did not enlarge.

I rely on you for the facts regarding what did and did not expand, but you are once again ignoring the fact that changes in the brain result from the implementation of new concepts. If modern research is correct, and if a similar process took place in pre-sapiens times, the implementation of new tasks resulted IN and not FROM the larger cortex.

dhw: Hence expansion, until brains could expand no more. From then on, complexification took over from the mix of complexification and expansion, as concepts gave rise to new concepts, culminating in all the improvements that go beyond the need to survive. All a natural progression that depends purely on the mechanism of brains reorganizing themselves in accordance with new requirements. No need for a God to preprogramme every single change or to dabble with every single brain even before changes are required.

DAVID: I believe God designed brains to enlarge and contract within the same skull size at each stage of hominin development. No dabbling required as you observe. But God had to provide the 200cc enlargement of skull as each new 200cc of frontal lobe cortex was added by Him.

I don’t understand why if your God had already designed brains to respond to new ideas by expanding and contracting (= rewiring and complexifying) when necessary, he wouldn’t (couldn’t?) also have designed brains and skulls to expand when necessary. Once again, why should we ignore modern science (which tells us that the brain changes in response to new concepts/tasks), and instead believe that the brain and skull changed BEFORE new tasks were even thought of?

dhw:But it is perfectly reasonable to argue that such a mechanism requires design, and THAT is your strongest case for the existence of a designer (coupled, in my view, with unexplained psychic experiences).

DAVID: Thank you.

It is essential that we separate the issue of God’s existence (which I never discount) from that of how evolution works, whether God-made or not. I am the baddie in all these discussions, because without a positive belief of my own, I can only look for the flaws in other people’s beliefs. You will have noticed that I can no more accept reblak’s atheistic explanation of life and the universe than I can accept your theistic explanation.