Brain expansion: different theories about rapid expansion (Evolution)

by dhw, Friday, September 25, 2020, 11:45 (1302 days ago) @ David Turell

dhw: All compartments of the brain consist of cell communities with different (though often interconnected) functions. If one cell community can add neurons, so can they all. And they did! But according to you, it was your God who operated on the earlier brains and added the cells – but he didn’t have to operate on the modern hippocampus, whose cell community was able to do the addition all by itself.

DAVID: We don't know at which stage of brain size the hippocampus was given the ability to add cells. We only know what happens now. God provided the extra cells for complexification in this brain and while it reorganized it shrunk. You can imagine anything else you wish to.

Since we only know what happens now, and we know that the brain cells autonomously complexify and even add new cells in response to new requirements, it is absurd to reject the possibility that the same thing happened in former times. Theistic version: your God gave all cell communities the ability to complexify and/or expand, and they did so in response to new requirements. The human brain discarded some cells when the efficiency of complexification made them redundant (shrinkage). But of course “you can imagine anything else you wish to” – hence your theory that your God performed operations on little groups of hominins and homos to add new cells before they were actually needed.

dhw: I asked you for proven instances, and all you can come up with is a repetition of your unproven theory that your God enlarged the brain in anticipation of the hominin producing new artefacts, whereas my theory is that the hominin’s brain expanded through the process of producing new artefacts! By contrast with your theory, I have the proven example of the modern brain, which changes IN RESPONSE to new requirements and not in anticipation of them.

DAVID: Same reversed twist. Our enlarged brain responded to new requirements and reorganized only after a long stasis period when it was not used differently than in the past and then it shrank as the new neurons were used.

There is no reverse twist. We are discussing the possible cause of expansion, which I propose was a RESPONSE to unknown new requirements. Thank you for confirming the known fact that brains do reorganize themselves in RESPONSE to new requirements. You complained that my theory is unproven, so I asked you for proven instances of the brain altering its structure BEFORE new cells are required. You couldn’t, whereas I have proven instances of the brain changing IN RESPONSE to new requirements. And yet again: post-expansion stasis (resulting from the fact that there were no new requirements) and shrinkage (because efficient complexification made certain cells redundant) are irrelevant to the question of WHAT MADE BRAINS EXPAND. Please stick to the point.

DAVID: I don't accept your strange version of why errors occur. I have God in control.

dhw: Having told me I want errors to run evolution – the exact opposite of what I have said – you now refer to an explanation of why errors occur, whereas I keep repeating that in the context of evolution there are NO errors! You are the one who keeps harping on about evolutionary errors! In my theory, the changes are designed (by the cells). And how can your God be in control if he has given molecules the freedom not to follow his instructions?

DAVID: My approach, as usual, is totally different. To answer the bold, God purposely set up the best system of living biochemistry He could. He ran a tight program of evolution, as noted in today's other entry that presents convergence again. God would trust intelligent cells that He created only if He gave them explicit guidelines for new advances. All presented before.

The “best system” entailed giving molecules the freedom to disobey his instructions, which means he is NOT in control! That is why, according to you, he did his best to correct the errors but sometimes failed. Convergence fits the pattern of intelligent cells responding in similar ways to similar problems. If God was unable to control disease-causing cells which disobeyed his instructions, why do you assume that evolutionary cells could do nothing but follow his instructions? See the "errors" thread for further discussion.