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

by dhw, Wednesday, May 31, 2017, 12:48 (2731 days ago) @ David Turell

dhw: You have now totally ignored all the previous arguments (repeated below) and are suddenly telling us that the current shrinking brain proves that the enlarged brain must have preceded the enhancement of consciousness. Why? It simply suggests that increased density is now more important than size.
DAVID: Increasing density is due to more complex use of a very responsive brain.

Precisely.

DAVID: Remember complex use started 10,000 years ago, with very simple use before then. The vast brain was there waiting for uses to appear. Now we see the new effect.

And still you ignore all the previous arguments, even though you acknowledge them again below! Yes the vast brain was waiting, and the question is what originally caused it to expand. The brain responds to usage. Concepts first, brain response second (dualistic view). The brain expanded through usage. Approx. 200,000 years ago, after approx. a couple of million years of saltatory enlargements through usage, it reached homo sapiens size and stopped growing. Subsequently usage resulted in densifying because otherwise the balloon would have burst.

dhw: If I were a dualist and an afterlifer, I would say that since consciousness/the self is separate from and survives the brain, which is only a receiver, and since consciousness uses and actually changes the brain, it is clear that consciousness provides the concepts, and the brain responds by changing itself – in the early days by way of enlargement, but later by way of densifying.
DAVID: I would agree to all of this in a way, except the consciousness/me/self are the same and so I produce the uses and concepts which modify a brain that is already large and can handle the conceptual processes as they appear.

There is no “except”. I am the one who keeps reminding you that consciousness/me/self are all the same. That is the essential element of your dualism which tells you that it is consciousness that modifies the receiver, and so it is only logical that enhanced consciousness caused the receiver to enlarge, and not enlargement that caused enhanced consciousness.

dhw: And if I were a dualist, I would oppose any view that made the evolution of consciousness dependent on the growth of the brain. As a dualist, you have agreed with all of this. And yet suddenly, for no clear reason, you think a bit of shrinkage invalidates it all.
DAVID: Not at all. Shrinkage tells us the a highly used brain can become more dense and shrink and is simply a measure of the new usage. I've said in the past and again now, enlargement of the brain made it a better more competent receiver of consciousness. Size first, use second.

Yes, shrinkage tell us that the brain can shrink, and usage makes it become more dense. And yes, enlargement made the brain a more competent receiver. Here once again is the dualistic sequence: usage leads to brain enlargement, but once the size has been fixed (say, 200,000 years ago) it already exists before the new thoughts arrive and require greater density instead of enlargement. Usage first, size second, further usage third, density fourth.