Brain expansion (Evolution)

by dhw, Friday, July 31, 2020, 11:56 (289 days ago) @ David Turell

DAVID: Sapiens in Morocco appeared 315,000 years ago with NO NEW changes in their lifestyle or artifacts. 50-70,000 years ago language started to appear. Caves were still used until much later. All stasis, no invention of the great idea you propose caused it!!! No evidence of anything new.

For the sake of brevity, I shall edit this post in order to focus on the salient points under discussion.

dhw: You keep talking as if the Moroccan sapiens meant an overnight change from pre-sapiens to sapiens. This has always seemed absurd to me. The whole human evolutionary process is shrouded in mystery, and the five Moroccans do not solve it, as this article shows:
World’s oldest Homo sapiens fossils found in Morocco

QUOTE. “H. sapiens evolution happened on a continental scale,” Gunz says. Support for that picture comes from the tools that Hublin’s team discovered. They include hundreds of stone flakes that had been hammered repeatedly to sharpen them and two cores—the lumps of stone from which the blades were flaked off—characteristic of the Middle Stone Age (MSA). Some researchers thought that archaic humans such as H. heidelbergensis invented these tools. But the new dates suggest that this kind of toolkit, found at sites across Africa, may be a hallmark of H. sapiens.

(dhw: Then maybe one factor in sapiens' brain expansion really was new tools. There is certainly nothing here to damage my theory.)

DAVID: None of this tells us when the MSA tools first appeared and certainly doesn't tell us that pre-sapiens had the first thought of it which then drove the expansion.

No, it doesn’t. But it doesn't disprove my theory either. I don’t know how often you want me to repeat that NOBODY knows the cause(s) of expansion.

dhw: No sudden leap from nowhere. As regards stasis, please explain why, in your own theory, your God stepped in one night 315,000 years ago to give some Moroccans bigger brains (with unnecessary 150 cc), skulls and pelvises, only for them and their descendants to do nothing with them for the next 270,000 years.

DAVID: God gave us the big brain, from which stasis shows we took time to learn how to use it.

According to you, there were no advances for 270,000 years! How do you know we were learning to use it if we didn't produce anything new?

dhw: NOBODY knows what caused the expansion, but new artefacts might have been a factor.

DAVID: We do not know the length of time the Moroccan sapiens had been around, when the artifacts were made of or thought of. I agree artifacts are a factor.

So your reference at the head of this post to the Moroccans does not in any way contradict my theory.

DAVID (re shrinkage): Your assumption that the extra neurons were never used, is not my theory. My point is that many of them were used in the plastic reorganization of our brain to fit our new uses and needs.
dhw: My point was that the brain itself was not reorganized. I asked: do you think the cerebellum became the cerebrum. The different sections remained the same, but every new activity required new complexifications, some of which resulted in the superfluity of certain cells, which were discarded. None of this flannel about them being “used in the plastic reorganization of our brain to fit our new uses and needs”. Your list confirms that the brain changes IN RESPONSE to new requirements, and my theory is still that the same process would have applied to earlier brains, whether the changes were complexifications or expansions.

DAVID: You can reject the 'flannel' as I reject yours, but I described obvious reorganization that had to occur with new uses. You bolded comment was silliness.

I objected to your statement that the brain was “reorganized”. This gives the impression that the sapiens brain was totally different from preceding brains (perhaps part of your attempt to show why your God had to do a dabble?), but all your examples clearly show that the areas of the brain were the same. Complexification of individual areas does not = reorganization of the brain.

David’s second post deals with more finds relating to tools, which further confuses the issue of who did what when.

DAVID: We can agree that bigger brains are consistent with better made tools. What caused the bigger brains is our dispute. I'll stick with God running evolution.

My theory does not exclude God, but if he exists, I propose that his involvement lay in creating the mechanism which “ran” evolution, including brain expansion: instead of every detail being preprogrammed or dabbled, the cells of which all organisms are made were given the intelligence to do their own designing, including brain expansion.

DAVID: Proof of your theory requires as much faith as mine as there is no direct evidence. This article of findings 70,000 years before the Moroccans, with no fossil evidence shows the tools were around, and some of our homo ancestors were doing it. We have no proof if this new homo idea created sapiens brains.

Agreed. If there was proof of either theory, it would now be accepted as fact. But it’s belief in the theory, not proof of the theory, that requires faith.

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