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

by dhw, Thursday, November 09, 2017, 14:11 (33 days ago) @ David Turell

DAVID: This is the one example I've found. Lucy's anatomy is so different many changes are required. The fossils don't provide them.
dhw: So how on earth does that prove that your God changed one lumbar vertebra 23 million years ago in order to prepare the way for Lucy 20 million years later (in order to prepare the way for Homo sapiens)?
DAVID: Preparation for bipedalism had to start somewhere and at some time. You don't accept goal oriented evolution managed by God.

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.”

QUOTE (under “Archaea and neuclei”): "Packed inside the nucleus of every eukaryotic cell is several feet of genetic material that is compacted in a very specific way. Small sections of DNA are wrapped, like thread around a spool, roughly two times around eight small proteins called histones. This entire DNA-histone complex is called a nucleosome, and a string of compacted nucleosomes is called chromatin."
DAVID’s comment: More evidence for pre-planning the future of evolution, just like a change in monkey lumbar changes.

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?

DAVID: I see no driving force in environmental challenges, but I see a force in God.
dhw: Challenges and opportunities. You cannot see that if food was scarce on land, organisms might be forced to seek it in nearby water, or if trees disappeared, tree-dwelling organisms might be forced to spend more time on the land, and such changes might lead to changes in the anatomy? Meanwhile, do you really believe that God was "driven" to specially preprogramme or dabble eight pre-whales, the weaverbird’s nest, the skull-shrinking shrew because it was the only way to keep life going until he could produce the brain of Homo sapiens?
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.

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.

dhw: (under “multiple neuron types”): Once again you are acknowledging that thought changes the brain. If it can shrink the brain by altering existing neurons, why do you think it can’t expand the brain by adding neurons?
David: Because expansion, as shown by the fossils is 200cc at a time and involves a binary process, expanding the bony skull. Shrinkage is at the scale of epigenetic modification, while the enlargements are speciation.
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.

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.

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: 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.

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.


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