Evolution and humans: big brain size uses energy (Evolution)

by dhw, Friday, November 10, 2017, 13:51 (2568 days ago) @ David Turell

DAVID: Preparation for bipedalism had to start somewhere and at some time. You don't accept goal oriented evolution managed by God.
dhw: Why “preparation”? Yes, bipedalism started somewhere, and developed from a little bit to total. That still doesn’t explain why your all-powerful, all-controlling God, twiddles one lumbar vertebra 23 million years ago for no practical purpose whatsoever, and takes another 20 million years to get to the Lucy stage when all he wants to do is produce Homo sapiens and his brain. Are you going back to the idea of “limitations”? “Dammit,” said God, “I really want full bipedalism, but at the moment I just can’t seem to do more than one lumbar vertebra.”
DAVID: Your problem is you don't look at history with a sense of purpose like I do. God prefers evolving things. No evidence of limitations, although I admit it is possible that He must use evolution because of some intrinsic limitations.

Your problem is that you try to impose one particular purpose on history, and it simply doesn’t fit. Why would a God whose purpose is to produce a bi-pedalling Homo sapiens fiddle with one useless lumbar vertebra 23 million years ago, and then 20+ million years later with umpteen different types of hominin, hominid and homo, some of them unrelated? And that’s without even mentioning the billion other organisms, lifestyles and natural wonders extant and extinct. You have the same problem with the giant universe. Your reading of God's mind simply doesn't explain the history.

DAVID: DNA works throughout all evolved organisms, and is a highly complex code, the origin of which not explained, except in my view by a designer. The human brain arrived. That is proof enough for me.

As usual, you are conflating two separate issues. The complex code as a case for design is the strongest one you have for the existence of a designer. I have never denied that. But it has absolutely nothing to do with your insistence that it was designed for the purpose of producing the brain of Homo sapiens. It also produced the duckbilled platypus, the mosquito, dead dinosaurs, skull-shrinking shrews etc.

dhw: There are small modifications and large modifications, depending on the nature of the challenges and opportunities. Land-dwelling pre-whale to water-dwelling whale and tree-dwelling ape to ground-dwelling hominin required large modifications. Finches only required small modifications. All these were driven by environmental change, but you see no “driving force” in environmental challenges.
DAVID: Environment is only one of many reasons for adaptations. Only very major changes related to mass extinctions are that important.

Environment encompasses climate, living conditions, predators, food shortage, pollution…so please tell us some of the many other reasons there are for adaptations. As for major changes, why should these not arise from local conditions and then spread further afield if successful? Localized changes may very well have been the trigger for tree-dwelling apes to descend to the ground, thereby causing the transition from pre-human to human. No mass extinction necessary.

dhw: The question is simply to what extent the known autonomous mechanism for change (in this case complexification and shrinkage) is capable of larger modifications (expansion of brain and skull). We don’t know the answer, which is no reason to jump to the conclusion that your God must have preprogrammed or dabbled it all.
DAVID: You may not accept the answer, but enlarging the frontal lobe by 200cc and expanding the skull requires multiple coordinated mutations and can only be accomplished by a planning mind , God's.

I certainly accept that the expansion required coordinated mutations (though not random), just as bipedalism, flight, land-to-water, water-to-land all required coordinated mutations, and these could only be accomplished by the cooperation of cell communities. You say God preprogrammed the cells 3.8 billion years ago or dabbled with them to make them cooperate – a hypothesis as unproven as my own. See above.

dhw: As for the bush of hominins, many not in our line, doesn’t that make you wonder why, if your all-powerful, always-in-control God’s prime purpose was to produce the brain of Homo sapiens, he produced a bush? Doesn’t the bush suggest a free-for-all? Or a God who just isn’t in control and can’t get what he wants?
DAVID: As before He prefers evolution to reach His goals. He gets what He wants, and yes, limitations are possible.

One moment he’s in total control, the next moment he’s not, he can do it (early Cambrian), he can’t do it (bipedalism, sapiens’ brain), and the irrationality of wanting one thing and producing billions of others is explained by the fact that you think his mind works that way, and human logic is irrelevant.

DAVID: And then you always add He can step in and dabble! You imply He carefully watches a free-for-all. And if He dabbles He guides it. You can't have it both ways.
dhw: If he exists, then of course he can watch AND dabble. And of course I can have it both ways! He watches the dinosaurs messing about for 180 million years, gets fed up with them and chucks a comet at them.
DAVID: Yes!

Thank you. At least we can now get rid of that non sequitur.