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

by David Turell , Thursday, November 09, 2017, 20:27 (2569 days ago) @ dhw

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.”

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.

DAVID’s comment: More evidence for pre-planning the future of evolution, just like a change in monkey lumbar changes.

dhw: The duckbilled platypus, the mosquito, dead dinosaurs, skull-shrinking shrews and even bacteria contain DNA, which is essential for evolution. How the heck does this prove that just like a change in one monkey vertebra, evolution was planned to produce the brain of Homo sapiens?

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

DAVID: Of course all living organisms have to seek food, but that is not prove they have to modify to the point of speciation. All Darwin's finches do is modify beaks back and forth in size.

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.

Environment is only one of many reasons for adaptations. Only very major changes related to mass extinctions are that important.

DAVID (on this thread): The shrinkage of the brain is at the same level of modification as Darwin's finch beaks, epigenetic, nothing more. You cannot escape brain size changes implying speciation. Body proportions also changed. Just compare us to Neanderthals. There are a whole herd of various hominins with various brain sizes and body shapes, literally a bush of them, many not in our line.

dhw: As I said in my previous post, the definition of “speciation” is a red herring. 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.

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.

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?

As before He prefers evolution to reach His goals. He gets what He wants, and yes, limitations are possible.

DAVID: But God is in control making your proposed choices. It is God who is making the choice!
dhw: Of course God, if he exists, makes the choice, and in my hypothesis he chooses to allow a free-for-all, which is the opposite of choosing to control everything.
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.

Yes!