Brain expansion (Evolution)

by David Turell , Tuesday, July 21, 2020, 18:45 (1373 days ago) @ dhw

DAVID: I'll repeat your proposal. Older smaller less complex brain thinks of new tool (artifact) concept, but can't produce it until a new larger brain implements the idea. Correct that statement, but that is my interpretation of your theory.

dhw: I don't know why you keep trying to rephrase my theory for me, but this is not quite right. Older, smaller, less complex brain thinks of new concept, and the process of implementing the concept causes the same brain to expand.

Are you now claiming the older smaller brain starts the process of implementation? If that is so, explain sapiens stasis in artifacts for 270,000+/- years. You haven't, and this denies archaeological evidence which always finds new artifacts with bigger brained fossils.

DAVID: The sapiens history does not support it. Just stasis for 270,000 +/- years after arrival of new brain. Why stasis if a new idea is driving expansion? Implementation should be quick if under your idea of driving the expansion.

dhw: The stasis refers to the fact that after the expansion there were NO new ideas that required changes to the brain! Of course implementation of the original brain-changing idea would have been relatively quick: old brain…new idea…brain expands to sapiens size. No more new ideas for 270,000 years. That = stasis. Suddenly there are new ideas, but instead of expanding, the brain implements the new ideas by enhanced complexification. What is your problem?

Where are the immediate new artifacts? In your explanation they don't exist, and an enlarged brain is not implementation; a new idea alone does not cause expansion in your original version. Are you changing it?

dhw: Plasticity is what allowed all brains to complexify and early brains to enlarge. I don’t see how your God’s giving his group of homos an overnight injection of an unnecessary 150 cc of brain allowed anything, since whatever was injected minus the 150 ccs would have worked just the same without it.

DAVID: Plasticity did not cause enlargement, just rearrangement of neuron networks. The extra 150 cc allowed us to self-tailor our brains, a very reasonable supposition.

dhw: I did not say plasticity CAUSED enlargement! The brain could not expand or complexify without plasticity! What does “self-tailor” mean? Did we use the extra 150 cc or didn’t we? Apparently not, according to you: for 270,000 years there was stasis, and when we came up with our new ideas, the extra 150 cc proved unnecessary and disappeared.

Self-tailoring is obviously refinement of what we were given and we got rid of extra neuron networks, as history tells us, as unnecessary. Very obvious.