Human evolution; savannah theory fading (Introduction)

by dhw, Friday, August 05, 2022, 08:16 (839 days ago) @ David Turell

Brain expansion

dhw: I propose that our additional cells followed exactly the same pattern as before: all our ancestors had “freedom of development” – which resulted in the addition of cells when needed! But for reasons unknown, we reached a stage at which complexification took over from expansion and proved so efficient that some cells became redundant. You agree, so what’s the problem?

DAVID: That is not my position. Based on how our brain arrived with excess neurons, I'm convinced Habilis and Erectus had similar beginning excess capacities. Our brain must reflect the past forms.

dhw: This is new. There is no evidence that Habilis and erectus brains shrank – on the contrary, we know that erectus’s brain expanded, i.e. added new cells, presumably as and when there were new requirements.

DAVID: There are not enough fossils to answer all question, but brain shrinkage is accumpianed without skull case shrinkage.

Correct. So what makes you think that habilis and erectus began with “excess capacities”, as opposed to their having acquired new cells to meet new requirements when their existing capacity for complexification had been exhausted?

DAVID: So you assume the needed extra cells in new species simply appeared magically? New designs require a designer.

dhw: There is no magic if you accept the theory of cellular intelligence (possibly designed by your God)! At every stage, when complexification could no longer cope, new conditions/discoveries/inventions/tools/lifestyles required additional cells for their implementation. But for some unknown reason, sapiens’ brain generally stopped expanding, and complexification took over, with such efficiency that cells which had previously been necessary then became redundant. You keep agreeing with this last explanation, so I don’t know why you keep faffing around with new objections.

DAVID: I agree with your description of events but reject your intelligent cell theory.

So long as you agree with the theory that new cells were acquired when new conditions etc. demanded an increase in capacity, we can leave it open as to the nature of the mechanism. My objection is to your theory that new “excess” cells were acquired when they were not needed, purely in anticipation of future requirements that did not yet exist.

Dhw: […] [i]you have not yet given us your own theory as to why our brain stopped expanding and reverted to enhanced complexification instead. Please tell us.[/i]

DAVID: I have told you previously: God designed our brain as an endpoint in evolution. It came with all the capacity it would ever need. Its conceptualizing ability seems endless based on present evidence of ideations. It came oversized to allow us to mold it as we willed. It came with a complexification mechanism to accommodate our free use of it.

dhw: You are talking as if your God designed our brain from scratch! It evolved from all the earlier brains and it reached a point at which it stopped expanding. You have agreed that all previous brains would have had a complexification mechanism, but at all stages except ours, this proved inadequate for new requirements and so they produced additional cells. I propose that no brain, including our own, was “oversized”, and why on earth do you think that the cells of erectus’s brain could not complexify as they “willed”. Was erectus a robot? Did habilis not have “free use” of his brain?

DAVID: God does design from scratch when first brains appeared and designed all future modifications. I've said previously erectus and habilis had free will. You've invented my mind as changing.

I asked you to give us your explanation for why our brain stopped expanding and complexification took over. Your explanation is that our brain was “oversized” (whereas earlier you agreed that “cells which had previously been necessary then became redundant”) and the new cells enabled us to “mold it as we will”, and it came with a “complexification mechanism to accommodate our free use of it”. But these characteristics are no different from those of the brains that preceded ours, so how does the above explain why our brain stopped expanding???

DAVID: (under “prediction machine”) As in the past I've always noted the brain is designed to help us use it.

I’d have thought that every cell in every organ and organism was “designed to be used” by the organism.