Evolution: more genomic evidence of pre-planning Part One (Evolution)

by dhw, Saturday, April 17, 2021, 11:41 (1104 days ago) @ David Turell

DAVID: I agree all previous brains had the same complexification capacity. I agree the new expansion covered the needs of that time. But saying not excessive in size or neuronal network complexity at that time is poor reasoning, when we find enormous new brain usages starting 250,000 years later in an unchanged brain waiting to be used.

Why have you suddenly added “excessive in neuronal complexity”? You have once again completely missed the point of my theory: Each expansion – including that of sapiens – was a REPONSE to a new need, and the new expansion then “covered the needs” of all brains, including sapiens, so long as complexification was able to do so. But 250,000 years after sapiens’ initial expansion, NEW REQUIREMENTS arose that could not be covered by existing complexification, and so the hitherto “unchanged brain” now had to change. This would normally have been by further expansion, but the brain did not expand. (I have offered a reason why: possible anatomical problems). Instead it enhanced its ability to complexify. And this proved so efficient that some of the cells that had been essential since the initial expansion were no longer needed – hence shrinkage.

DAVID: Our fresh new brain had lots of new extra cells, never used until much later in specialized areas of the frontal and prefrontal lobes with intricate five special layers of neurons in a special tandem network. This allowed our new abstractions of thought that we are familiar with now.

How on earth can you possibly know that the new extra cells – which I propose were NEEDED in order to meet the new requirements – were never used? What would have changed after 250,000 years was the manner in which the neurons combined to form new connections. You persist in ignoring the very clear statement I quoted earlier: “…what sets us apart from other mammals is not so much brain size but reorganization of our brains in terms of connectivity and neurotransmitter changes.” This is what would have happened when the existing extra (but NOT excessive) cells could no longer cope with the new requirements.

dhw: […] I do not ask you to believe the theory, but I do ask you for a logical reason for rejecting it. You have not yet offered me a single one.

DAVID: It is totally unreasonable. Many extra cells are many extra cells, no matter ow you try and twist it. The stasis until their use cannot be tossed away with by the contorted explanation you present. Thrown away extra cells were extra cells from, the beginning.

Yet again: in my theory the many extra cells were needed in order to meet whatever was the new requirement 315,000 years ago. If previous expansions, as you agree, “covered the needs of that time”, why on earth would you assume that our own expansion did NOT simply cover the needs of that time? You harp on about stasis, but stasis was always the case once the new requirements had been met. Our ancestors lived for hundreds of thousands of years with no further expansions. In our case no change was NEEDED until 250,000 years had passed. And so yet again, what logical objection can you have to the proposal that our extra cells WERE needed, were NOT excessive, and only become unnecessary when enhanced complexification had taken over?

DAVID: You just don't like my point that God enlarged the brain in anticipation of future use.

dhw: True. It goes against what we know of the modern brain, and I find it far more logical to assume that any changes in the brain and in the anatomy would have an immediate cause, as opposed to being preprogrammed 3.8 billion years ago or being the result of your God performing a series of operations (dabbling) in anticipation of some future need. In this respect, our prime example was your insistence that he replaced the legs of pre-whales with flippers BEFORE they entered the water. And yet you accept that organisms RESPOND to new conditions by adapting themselves!

DAVID: All we know, and you have used another distortion of our agreement on this, organisms have minor necessary epigenetic adaption but stay the same species. No one can identify how species appear. I say God does it by design.

If anyone could identify how species appear, we would not be having this discussion. There is no distortion: you have explicitly claimed that your God must have changed legs into flippers before pre-whales entered the water, just as you claim that your God must have operated on pre-sapiens brain before we actually needed the extra cells. I would regard both cases as major adaptations rather than innovations, but the distinction is irrelevant. My proposal is that evolutionary change comes about through responses to new requirements, not through anticipation of them. I am quite happy to don my theist’s hat in these discussions, because my theory allows for your God as the designer, but instead of designing every life form, econiche, strategy and natural wonder, he would have designed the mechanism which enabled organisms to do their own autonomous designing. And apart from repeating your own preconceptions, you still haven’t given me one logical reason for rejecting this proposal.