Brain expansion: different theories about rapid expansion (Evolution)

by dhw, Thursday, September 10, 2020, 11:19 (1317 days ago) @ David Turell

dhw: I don’t know why you persist in using the word “natural”, as if somehow it excluded your God as designer. If he designed a mechanism which led to AUTONOMOUS complexification and small-scale addition of cells in the modern brain, as you yourself believe, firstly this is hardly “one small aspect”, and secondly the SAME mechanism might well have led to AUTONOMOUS complexification and large-scale addition of cells in earlier brains. But yes, it is a straight line extrapolation from the only facts we have.

DAVID: I use natural to distinguish from supernatural, God.

I thought so. My proposal incorporates God as the possible designer of the mechanism which has led to autonomous complexification and expansion.

DAVID: Your 'might well have' thought is still pure supposition as you now agree.

Nobody knows the cause of the expansions, and so I offer a theoretical explanation based on the known facts of how the modern brain operates. Your belief that your God performed brain/skull/pelvis operations on groups of hominins and homos is “pure supposition” based on no known facts that I am aware of.

DAVID: I approach thinking about God from every aspect we can use to draw as broad a concept as I can. That is why we disagree about Him. I get the sense you pick and choose in a biased way.

In the context of evolution generally, you offer us one fixed belief, the component parts of which cannot be fitted together logically. I offer a variety of alternative explanations which you agree are logical, and all of which entail the possibility of your God as the creator. (I am an agnostic.) In the context of brain expansion, I offer an alternative to your fixed belief, while acknowledging that it is only a theory. Which of these two approaches would you say is more indicative of bias?

DAVID: My view is a holistic approach taken from all the broad range of facts we have. Your proposal of response to demands, as above, implies to me the driving force should result in immediate production by an advanced brain, but we both agree there are thousands of years of stasis. If the needs are so strong there is massive enlargement, why are there no new results? Your theory has no logic.

dhw: The quote concerning response to demands is from you, describing how the brain works. I don’t know how often you want me to repeat my proposal regarding stasis, but here we go again: the brain expanded when unknown new requirements could not be met by the existing smaller brain. Once those requirements were fulfilled, the new sized brain did not need to change until it had to meet the next new requirements (e.g. new ideas, ways of life, changes of environment), and we see periods of stasis following every expansion including ours. The brain changes as required. It does not change in anticipation of new requirements. Our own brain apparently underwent changes after a stasis of some 280,000 years, when there was a sudden burst of new ideas.

DAVID: As usual the bold does not fit history: the new-sized fossil skulls, when found are accompanied by new improved artifacts. You try to make the point the artifacts might have appeared as the brains were still enlarging. But the Moroccan sapiens of 315,000 years ago offer nothing to support that until 260,000 years later!!!

This is becoming silly. Read the bold! “The brain expanded when unknown new requirements were fulfilled.” Look at what follows, as examples of new requirements: “e.g. new ideas. ways of life, changes of environment”. I didn't even mention artefacts, but earlier we took them as a concrete example, because in some cases, as you say, the new-sized fossil skulls were accompanied by new artefacts, thus providing possible evidence that these were the “new idea” which could only be implemented by adding new cells. But the cause is UNKNOWN. If we knew it, there would be no debate.

DAVID: What was planned in advance was our large human brain ready to go when we learned how to use it.
And
DAVID: I think God keeps hands on.

dhw: Yes, I know you think your God performed a brain/skull/pelvis operation on a bunch of sleeping Moroccans, but now his great plan was simply to make their brains do what every preceding brain had always done: to adapt in reaction to new requirements, as you have said yourself. And you still haven’t found one good reason to reject the possibility that the autonomous mechanism (perhaps designed by your God) which gave Moroccans this ability, leading to complexification and the addition of a few cells, might also have enabled past brains to complexify and add a lot more cells, as required at that particular time.

DAVID: See my refutation of this distortion of historical facts above.

See above for my refutation of your distorted version of my argument. Now please offer me one good reason why the autonomous mechanism which enables the modern brain to adapt to new requirements by complexifying and adding a few new cells could not possibly have complexified and added a lot of new cells in earlier brains, also in response to new requirements.