Brain expansion (Evolution)

by dhw, Saturday, June 20, 2020, 10:24 (1406 days ago) @ David Turell

dhw: The autonomous mechanism which now responds to the demands of your dualist’s soul by complexifying would also have responded to the soul of our ancestors, but would have reinforced itself if its existing capacity was unable to cope with a particular new requirement. There is absolutely no chance involved. Nor is there any “foresight of what is intended”. The brain RESPONDS to the requirements of the soul; it does not anticipate them!

DAVID: You are forgetting stasis of use. A new-sized brain has more cortical neurons but new uses always take time. Where is the push to enlarge you seem to be describing? In your scheme of enlarging, there should be no stasis.

The push for pre-sapiens enlargement came from a requirement which could not be met by the existing capacity for complexification. Once the brain had enlarged, there was comparative stasis in the new “culture” in all instances, including sapiens, and so we can only assume that there were no new requirements, or those that there were could be deal with by complexification. You seem to think that once the brain had expanded, the dualist’s soul should have come up with millions of new ideas. Wrong way round, as usual: it is the soul’s new ideas that would earlier have required complexification and then expansion, and which in the modern brain cause complexification, which in turn is so efficient that it has caused shrinkage. The dualist’s brain does not produce ideas – it responds to the ideas conceived by the soul. (From a materialist’s standpoint, the soul = the thinking part of the brain, which leads to lots of complications best left to discussions on dualism v materialism.)

QUOTE: A certain gene called ARHGAP11B that is only found in humans triggers brain stem cells to form more stem cells, a prerequisite for a bigger brain.

DAVID: We now know what genetic change occurred to push human brain enlargement over five million years ago. In my theory God made the genetic change. His mind knew what would happen. dhw will tell us the brain cells themselves made the change. How did the cells know what they were doing?

dhw: […] Why do you insist that your God could not have given cells the intelligence to work out what they needed to do? Why does he have to tell ants how to build their cities, weaverbirds how to build their nests, stem cells how to add to their number? Back we go to the same question as before: if he could enable the brain cell communities to complexify themselves autonomously when needed, why couldn’t he enable them autonomously to add to their number when needed?

DAVID: Your comment simply shows that we totally differ in our concepts of God, when you are willing to consider God. As far as I am concerned God runs evolution with purpose.

Why do you think that a God who invents a mechanism enabling cells to expand their number autonomously = a God without purpose, whereas a God who invents a mechanism enabling cells to complexify autonomously runs evolution with purpose?

dhw: I am suggesting that for a period of time, there would have been lots of casualties until the big pelvis WAS "simultaneous" with the big baby head! That is why I asked you whether you thought the switch to large pelvises happened overnight, and if not, how long you thought it might have taken. You still haven’t answered.

DAVID: Do you have any idea how long your weird catch-up theory would take? Both attempting dead mothers and dead babies and nothing else? Much easier to accept the theory that it all occurred through simultaneous design by God, the designer.

dhw: So you do think the switch to large pelvises happened overnight. A group of homos woke up one morning and found that their brains and skulls and pelvises had suddenly got bigger. I’m afraid I don’t find that “much easier to accept” than the theory that there was a period of transition. But no, I don’t know how long it would have taken. It’s a shame that we don’t have a continuous record of fossils to cover the hundreds of thousands of years between smaller and larger skulls.

DAVID: All solved if you can see God does it simultaneously. Otherwise no advance, just death.

The only observable parallel we have is modern adaptations, from bacteria combating new medications to fish learning to live in polluted waters. Many die before the adaptation is complete. But of course you are welcome to believe that your God did an overnight operation on all those ancient homos’ brains, skulls and pelvises. What a shock they must have had when they woke up next morning!