Brain expansion (Evolution)

by dhw, Thursday, June 18, 2020, 10:57 (1617 days ago) @ David Turell

dhw: In the pre-sapiens eras, survival would obviously have been the prime motive, so why bring in modern-era violin-playing as your example of new requirements?

DAVID: Violin playing is an advantage gained by the huge brain, not anything to do with survival, which is my point. Violin playing is never a protection for survival. You've just jumped back into Darwin mode, survival of the fittest tautology.

The subject of this thread is brain expansion – i.e. from pre-sapiens times to our own, when expansion stopped. It makes no difference whether the new requirements relate to matters of survival or otherwise, the process is the same: both expansion and complexification occur as a result of the brain responding to new requirements, not anticipating them. The violin example only applies to sapiens’ complexification.

DAVID: A giant jump in brain cortex and prefrontal cortex volume (about 300+ cc from erectus to us) implies a need for a very strong response. You want it naturally to happen and I feel only a designer could create such a large change.

dhw: I don’t see why a designer should be incapable of creating a mechanism for large changes as well as small changes.

DAVID: Again a judgement about who God is and what He might do. I've agreed to your IM mechanism many times but with God's guidelines onboard, which you always reject.

Of course I reject “guidelines”, which = a 3.8-billion-year-old programme for every change, or a direct dabble – the exact opposite of the autonomous mechanism I propose. Your theory is no less a judgement than mine about who God is and what he might do!

dhw: It would be more appropriate to ask why your God produced an oversized brain in the beginning! A mistake? Or what possible purpose could he have had? Do please answer. […]

DAVID: Bigger brain explained as allowing the appropriate complexification to occur to handle the new invention of activities humans developed like violin playing. Briefly it gave the bigger brain much more flexibility of response to the soul's new demands.

dhw: Thank you. At long last our theories are converging. Of course the bigger brain is better able to respond to the soul’s demands. That is why, in my theory, the brain expanded in the first place – it could not respond to the soul’s new demands because the existing capacity for response through complexification had reached its limit. In our earlier example, the dualist’s soul demanded implementation of the spear concept, and the brain had to expand to handle it; in your example it demanded implementation of the violin concept, and it was handled by complexification.

DAVID: I don't see a convergence. Violin playing is a sideshow from the real advances. Only you think the brain can enlarge itself. All it can do from the evidence is complexify itself and shrink. How did your cell committees know to overly enlarge the sapiens brain so it could complexify?

Violin playing is irrelevant to brain expansion. The only alternative to the brain enlarging itself is your God preprogramming and/or dabbling the expansion, and not everybody believes in God. There are various theories (random mutations, diet, discovery of fire) – ask any atheist. The evidence does indeed show that the brain can complexify itself, and so it is not unreasonable to propose that the same autonomous mechanism also engineered expansion. In my theory, the pre-sapiens cell communities would have recognized that their autonomous complexification process required reinforcements (= expansion), and finally that there was a limit to the amount of expansion possible. Hence enhanced complexification, which proved so efficient that certain cells became redundant. Your agreement that the brain RESPONDS to the new demands made by the dualist’s soul (as opposed to being changed in advance of new demands) is the breakthrough in our discussions.

dhw: Your response still hasn’t explained why your God would have produced a bigger brain than necessary, but my theory faces no such problem – complexification is so efficient that certain cells became redundant. My proposal does not, however, exclude your God. As with the rest of evolution, it allows for him to be the inventor of the whole system whereby cells/cells communities use their intelligence to respond to different requirements.

DAVID: The cell intelligence is seen in massive automatic molecular reactions God gave them.

That's your theory. And you still haven’t explained why you think your God made the sapiens brain bigger than necessary.

DAVID: Each new hominin. homo species with larger skull appeared suddenly after hundreds of thousands of years

dhw: And do we have fossils from all of those hundreds of thousands of years? Do you think the switch to large pelvises happened overnight? If not, how long do you think it might have taken?

DAVID: All we have is gaps, and Gould felt they were important. In questioning gap size you are constantly avoiding that big pelvis must be simultaneous with big baby head appearance. Disagree?

I am suggesting that for a period of time, there would have been lots of casualties until the big pelvis WAS "simultaneous" with the big baby head! That is why I asked you whether you thought the switch to large pelvises happened overnight, and if not, how long you thought it might have taken. You still haven’t answered.