Brain expansion: different theories about rapid expansion (Evolution)

by dhw, Sunday, September 06, 2020, 11:03 (1322 days ago) @ David Turell

dhw: You wrote: “our brain has the adaptability to react to any and all physical and mental and emotional demands we place on it” and you have agreed that it reacts and adapts without God “stepping in”. The brain is a community of cells, and if he can give those cells the autonomy to react and adapt, why should he not have given the same autonomous ability of adaptation to all the body’s cells?

DAVID: The brain we got from God was oversized to begin with. Your theory is based on that example and then extrapolated beyond the only facts we have. The complexification mechanism works beautifully as designed. Do you think the pre-sapiens neurons knew enough of future use by sapiens to have self-designed by themselves such a mechanism for future use? I sure don't.

dhw: You seem to be obsessed with shrinkage, which is totally irrelevant to my theory! For the umpteenth time, my theory is based on the known fact that the modern brain – as you have confirmed over and over again – has an autonomous system enabling the brain to change IN RESPONSE to new requirements. These changes are mainly in the form of complexifications, but there are also examples of EXPANSION, and so it is perfectly feasible that the same autonomous system engineered complexification and expansion in pre-sapiens brains. And in answer to your question, no, I don’t think pre-sapiens neurons knew about future use! I think pre-sapiens brains expanded in order to meet new requirements – just as sections of the modern brain have done. It is you who initially harped on about your God “anticipating” how the enlarged brain would be used, but you then got in a complete tangle over what exactly he anticipated. I’m pleased to see you have now dropped that subject.

DAVID: As usual, ignore an oversized brain that shrinks, exactly the opposite to your theory about brain expansion. Nothing in the facts we have supports your idea. The only 'EXPANSIONS' in our brain relates to heavy use of memory in London cabbies, changes in musicians' brains with millimetres of thickness in small areas.

I have not ignored it. I have said that it is irrelevant. We have agreed over and over again that shrinkage is due to the fact that after the brain had stopped expanding, complexification took over as the major response to new requirements, and it proved so efficient that certain cells became redundant. Nevertheless, as you rightly point out, there are still instances of expansion to support the case for a mechanism that causes expansion IN RESPONSE to new requirements.

DAVID: The only expansion we know of from fossils are much larger than any current expansions.

That is the puzzle we are trying to solve. And since you agree that the modern brain undergoes changes (complexifications and small expansions) IN RESPONSE to new requirements, without any intervention from your God, it is not unreasonable to propose that it did the same in earlier phases of the brain’s evolution.

DAVID: As for God's knowledge about how we humans might use our brain, I'm sure He didn't anticipate every last usage in games we might invent, and I've listed possible examples. Distorting my part of our discussion again.

A week or so ago, you wrote: “”Engineering pre-sapiens expansion means…the designer’s anticipation of how that enlargement will be used.” I replied that this could only mean that he anticipated our invention of cricket and the piano. You replied: “The phrase in no way meant God knew specifics of what we humans invent.” I asked you in that case what he did anticipate, and you replied: “That we would dominate the world.” What was that meant to be an example of? You go on and on about your God dabbling expansions to prepare for the future, and you asked me if “neurons knew enough of future use to have self-designed by themselves such a mechanism for future use.” I keep repeating ad nauseam that changes in the brain – as you yourself have rightly pointed out – are caused by RESPONSES TO NEW REQUIREMENTS, and not by gazing into a crystal ball and preparing for what is to come. I’m sorry, but the distortions are all yours. And you still haven't explained why ancient brains could not have changed IN RESPONSE to new requirements, just as modern brains do.