Human evolution; savannah theory fading (Introduction)

by dhw, Monday, August 15, 2022, 08:21 (831 days ago) @ David Turell

Brain expansion

dhw: […] Are you now saying that your God had to specially design all the cells that were added to earlier cortices and give them a special new ability for complexification?

DAVID: Of course.

dhw: But I thought you agreed that earlier brain cells already had the autonomous ability to complexify. So when God operated on all these sleeping homos, he added the new cortex cells to the old ones, and separately designed the same ability to complexify as that of the existing cortex cells. Wouldn’t it have been a lot simpler if he’d just given all the complexifying cells the ability to add to their number when they needed to?

DAVID: Remember He specifically did in the hippocampus. If that ability is not elsewhere, that was His choice and answers your question.

dhw: It shows that the cells are capable of adding to their number! And so there is no reason to suppose that the same ability was NOT present in other parts of our ancestors’ brains, but when it came to us, complexification took over. We don’t know why the human brain stopped expanding. You reject the idea that it might have caused anatomical problems, but you have not provided any other explanation.

DAVID: I have explained it!!! It is complex enough to handle all our needs into the future.

Thank you. I had forgotten. But I wonder why the ability to complexify was suddenly enhanced to the degree that expansion was no longer necessary. Did your God decide he’d had enough of performing all these operations on sleeping hominins and homos, and he’d leave all future “operations” to the cells themselves – apart perhaps from one final fling with the hippocampus?

dhw: You simply agree that the autonomous mechanism for complexification took over. Once more: if you believe your God gave past and present cells the autonomous ability to complexify, why do you regard it as impossible for him to have given all of them the autonomous ability to add to their number (as shown by the modern hippocampus)?

DAVID: With God in control, He did all He wished. What we see is obviously reflecting His exact wishes.

And how do you know his exact wishes, and how does this prove that he did NOT give cells the ability to multiply?

DAVID: And you have offered no answer for the pelvic problem as before.

dhw: I have given you the same answer I gave you before, but if you prefer your own theory that your God preprogrammed bigger heads and pelvises 3.8 billion years ago, or performed operations on all those women’s pelvises, that’s fine. Death in childbirth wasn’t all that uncommon in historic times, so it’s perfectly conceivable that such a problem would have caused more deaths in pre-historic times.

DAVID: You are very uncaring for our ancestors.

dhw: This has nothing to do with me “caring”! With your doctor’s knowledge of all the problems relating to childbirth, why are you so certain that our ancestors had no problems and God “arranged it so new heads fit into new sized brains all at once”? Has he been so uncaring for all those sapiens mums who never made it?

DAVID: It turns out our birth canal is still tough to navigate.

Yes indeed, so why do you think our pre-historic ancestors had no trouble back in the days when baby skulls got bigger?