Evolution and humans: big brain size or use (Evolution)

by David Turell @, Thursday, May 18, 2017, 15:17 (63 days ago) @ dhw


dhw: You are jumping around like a cat on a hot tin roof in order to avoid the point I am making, which concerns the implications of your belief in the NDE scenario. In a nutshell: if you believe that our identity/”we”/the self, in the form of consciousness without body and brain, continues after death (as apparently experienced by NDE patients), then it can only be consciousness/”we”/the self that uses the brain, and not the other way round.

In NDE our consciousness which is our 'self' continues as an entity and returns to the brain when the brain returns to a physical living state to receive it. I am in control of my consciousness. I have free will. You are arguing that I don't. I use my consciousness. It does not use me as I am free to form my conscious self any way I want. The newborn with its partially formed brain is barely conscious, and has to learn to be self-aware. The relationship between brain and consciousness has to evolve over time. The attributes of consciousness are there for the taking and dev eloping and we do it as we mature.


DAVID: This thought follows from the fact that the gaps from Lucy to habilis to erectus to us are huge with gaps from 400cc to 1,200cc with no itty bitty changes. Please remember 200,000 years ago we had 1,200cc, but how much did we use it back then? Obvious.

dhw: I’m not sure how your question supports your claim that the brain uses us/our consciousness. As regards itty bitty changes, like you, I can only rely on what the experts tell us about the evolution of the human brain. Wikipedia disagrees with you:

Evolution of the brain - Wikipedia
https://en.wikipedia.org/wiki/Evolution_of_the_brain

The evolutionary history of the human brain shows primarily a gradually bigger brain relative to body size during the evolutionary path from early primates to hominids and finally to Homo sapiens. Human brain size has been trending upwards since 2 million years ago, with a 3 factor increase. Early australopithecine brains were little larger than chimpanzee brains. The increase has been seen as larger human brain volume as we progressed along the human timeline of evolution (see Homininae), starting from about 600 cm3 in Homo habilis up to 1736 cm3 in Homo neanderthalensis which is the hominid with the biggest brain size. The increase in brain size topped with neanderthals; since then the average brain size has been shrinking over the past 28,000 years. The male brain has decreased from 1,500 cm3 to 1,350 cm3 while the female brain has shrunk by the same relative proportion.[1] (My bold)

Apparently this shrinkage may be accounted for by more efficient arrangement and wiring, which I would suggest offers an answer to your last question. Clearly the brain cannot go on growing indefinitely, and so in order to accommodate the increasing demands of consciousness (I’m still following your dualist NDE line of thinking) it has to complexify its inner workings.

I don't see that Wiki disagrees with me. The size of brain statements are correct and your final statement is quite correct. I'm saying size first, use second, and your paragraph above supports that concept.


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