Human evolution: Neanderthal Y chromosome (Introduction)

by dhw, Tuesday, September 29, 2020, 14:10 (1295 days ago) @ David Turell

dhw: You have your God preprogramming or dabbling every change in anticipation of new requirements, whereas I propose that fins and enlarged brains are the result of new requirements.

DAVID: No need to change or repeat my known answers. God designs what is needed for each new advance, anticipating new abilities and activities.

Understood. So now will you please answer my questions: Did your God preprogramme upright walking semi-apes, or did he step in and do a dabble on the legs, leaving chests and brains alone until the next dabble? Why do you think he would preprogramme or dabble these interim changes? What purpose would they have served unless it was to meet some new requirement?

dhw: ...Nor have you responded to my argument concerning isolated populations.

DAVID: Answered several days ago in a comment you removed in your next reply:
Saturday, September 26, 2020, 11:22 (2 days ago) @ David Turell
QUOTE: Neanderthals had smaller populations than moderns, and small populations tend to accumulate deleterious mutations, especially on the X and Y sex chromosomes. (David’s bold)

That had nothing to do with the exchange I’m talking about, which I reproduce below. You challenged my proposal – in line with Gould’s theory – that isolated groups of pre-humans would have taken to life on the ground while the rest of their species lived happily ever after in the trees.

DAVID: But first all were groups of apes using trees. Do trees suddenly disappear over night? No, it was gradual, which means the ape groups could easily followed the retreat of the trees. Your natural theory, as usual, has huge holes.

dhw: You have just agreed that isolated populations cause large evolutionary advances. An isolated group of apes would be isolated for a reason. They would not “easily follow” anything that took them out of their isolation. But of course this is all speculation. Maybe tree life wasn't providing enough food for our little group of explorers. Or maybe there was too much competition.

May I presume from your silence that you now accept this as a possible explanation for some apes changing and others staying the same?

QUOTE UNDER “Human evolution A whale at altitude in Kenya”): “Here, uniquely, the region’s geologic and climate histories, including the formation of the rift system that is the cradle of humankind, are preserved in sedimentary rocks. Our collaborative work will tease out how tectonics and climate come together to drive evolution.”

And they could add all kinds of localized environmental changes as the forces that “come together to drive evolution”.