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

by dhw, Tuesday, June 27, 2017, 15:01 (2704 days ago) @ David Turell

dhw:We have agreed that “use” means the implementation of ideas, and it is clear that the brain is needed for this purpose. But I don’t know how the RECEIVER brain can be said to “shape” the ideas or the consciousness that provides the ideas, or the “content of experiences and memory”, if these exist independently of the brain, as you believe to be the case in a conscious afterlife.
DAVID: The living brain/me/consciousness is seamless in life, but after death is a total different issue. Only me/consciousness exists in that circumstance. Why do you try to assume life and death are the same circumstance for the brain? In life material brain, immaterial me/consciousness; in death immaterial me/consciousness.

Of course life and death are not the same circumstance for the brain! The brain is no longer there after death! But you believe that the immaterial you will continue to exist after the death of the brain, with the same capacity to think, the same memories, the same ideas. This is why it is a total contradiction for you to argue that in life the immaterial "you" cannot think or conceptualize without the brain, which you yourself keep telling us is only a RECEIVER. This can only mean that in life the brain does not do the thinking etc. but receives the thoughts and enables our immaterial self to express and implement them in the material world. It is no longer required when we move into an immaterial world. (I am simply repeating YOUR beliefs here. I remain neutral.) The rest of your post deals with the same subject, except for the following:

dhw: You say the changes to brain and anatomy PRECEDED the manufacture of spears and the use of language, whereas if the capacity for thought (consciousness) is independent of the brain, as is indicated by the NDEs you believe in, it would be thought that engendered the changes to brain and anatomy, just as the illiterate women’s attempt to read engendered changes to their brain.
DAVID: An other mixed conflation. The women already had a large complex brain. The plasticity of the brain allowed them to modify it with learning to read. With enough new uses by humans the brain shrinks, not grows!

Yes, they already had a large brain. I am suggesting that at some time in the past the brain reached a size beyond which it could not grow without serious consequences for the rest of the anatomy, and so later modifications took place through rewiring and densifying, as with the illiterate women. Shrinkage, I suggest, is the result of efficient densification.