Introducing the brain: half a brain is just fine (Introduction)

by David Turell , Tuesday, February 18, 2020, 18:33 (1738 days ago) @ dhw

DAVID: Since brain use allows so many new possible requirements, it has to have its current plastic abilities. God is a great designer allowing and preparing for future possibilities of use.

dhw: Of course it has to have its plasticity. And if God exists, of course he is a great designer! That does not alter the fact that the brain changes as usage dictates. It does not change in anticipation of usage.

That view does not take into account the jump of 200 cc with each new advance in homo/hominin fossils accompanied by an advance in artifacts, all after large gaps of time. Your theory requires a record of slow brain growth as individuals adapt to new circumstances, which does not exist

DAVID: The human brain was initially evolved with this degree of plasticity to handle whatever requirement the future could throw at it. Only foresight in design could have done this. But remember the modern human brain has shown shrinkage, so size is not an issue. The key is the innate complexity the brain has as well as its plasticity ability. Humans can invent any type of work for the brain to adapt to and it will. The fist hominin brain had no idea as to what was coming in terms of complex usage, yet our brain developed in advance of the usage across fossil gaps of major proportions, 200 cc at each jump. God at work.

dhw: Once more you are trying to defend your whole evolutionary thesis that your God preprogrammed or dabbled every new step before it was required. You simply ignore the one fact we know about brain development, which is that the brain RESPONDS to new needs through complexification and even enlargement of individual sections, and does not change in anticipation of them. All brains have to be plastic, or they could not learn, remember, communicate, devise survival strategies etc. You now force me to repeat my proposal: pre-sapiens brains expanded when the capacity was too small to meet new requirements (e.g. the implementation and usage of new means of survival). The expanded brain would suffice for so many thousand years until it could no longer cope with more advances, and so it expanded again. It reached maximum capacity with H. sapiens (further enlargement would damage the rest of the body), and so complexification took over, and this proved so effective that there was even some shrinkage. Development then took the form of complexification, because every change, as we know for a fact, is a RESPONSE to usage, and not a preparation. We do not know of any “development in advance of usage”!

I can accept the entire story, reflecting its Darwinian presuppositions, as showing the requirements for advancement, but produces no explanation for why the brain size jumped 200 cc each time a more advanced fossil species arrived. Your proposal requires tiny changes a la' Darwin's inadequate theory.

Under "tiny brain":

QUOTES: A tiny brain can run a big body in ancient an animal:
QUOTE: "The researchers suggest that because N. acreensis had few predators to outwit, a large brain simply wasn’t worth the maintenance costs."

DAVID: Just living in a quiet environment doesn't require much brain function. I agree with the reseachers' comment. dhw will respond the brain will expand if the animals are challenged, but think about that approach. how do the animals survive if the needed brain size for survival doesn't yet exist? Especially if one considers homo evolution with gaps in brain size of 200 cc with each new advanced species.

dhw: The brain responds to needs! You could hardly wish for a clearer example. Expansion was not required so the brain did not expand!

Using a weird double negative argument proves nothing. Nothing required, nothing done. Of course with a more complex life style/requirements the brain MUST be bigger. Our discussion is how it happens. Note, only after large gaps in size, which you really never explain by simply saying the jump was needed.