Big brain evolution: changes in sapiens skull shape (Evolution)

by David Turell , Thursday, February 15, 2018, 15:25 (2471 days ago) @ dhw

DAVID: Because his physical being was separated for a period from his s/s/c. Look at what you wrote above. The separation strongly supports dualism

dhw:Of course it does. The point in dispute here is not dualism but your continued insistence, directly contradicting your dualistic beliefs based on NDEs, that the s/s/c cannot THINK without a functioning brain!

Of course it thinks when separated from the body, but when it returns and is attached to the brain and the revived person receives its knowledge through the brain. A living person can reach his s/s/c only through his brain. The s/s/c has a role with the brain and separate from the brain. Dualism.

DAVID: You are attempting to combine two separate concepts. The s/s/c can think with or without a brain, but its level of complex thought generated within a living person depends on the complexity/size of that cortex. Think of this: was the s/s/c of erectus as complex as ours in the level of thought achieved? I believe the complexity of s/s/c evolved as Homo did.

dhw: So do I. The s/s/c evolves and complexifies with every new experience, but that doesn’t alter the basis of your dualism, which you keep forgetting: namely, that thought does not depend on the brain but comes from the s/s/c (see reminder below), in which case complex thought does not depend on complex brain!

But in my view it does. Only a complex computer can do complex simulations. The erectus s/s/c was not the sapiens current s/s/c, which is based on the hardware of our sapiens brain. Software and hardware have to match.

dhw: Every stage of evolution is carried over to the next stage. If the pre-erectus s/s/c thought of spears and his brain expanded with implementation of the idea of spears, erectus now has a larger more complex brain, and his s/s/c is now more complex and knowledgeable because of the new experience of making spears. And when eventually the erectus s/s/c comes up with some brand new concept demanding the same process of enlargement to implement the concept, we come to sapiens. And the sapiens s/s/c is now more complex, with all the new knowledge and experience of his predecessors, and he has a larger more complex brain.

Again you imagine a pushing mechanism to enlarge the brain. I am happy with God speciating each stage of enlarged brain.

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dhw: We are talking about advances in evolution. The pauses (stasis) take place when organisms have what they need to survive. The advances take place when (a) their survival is threatened, and (b) when individuals come up with new ideas that will IMPROVE chances of survival or IMPROVE modes of living.

DAVID: You are simply rephrasing 'survival of the fittest', which I do not accept.

dhw: As always, you try to ignore “improvement”, so please forget the expression which you dislike so much and which I have not used, and explain to me what you disagree with in the argument you have quoted, paying special attention to (b).

Improvement is answered in the other thread. I think the emphasis is complexity as explained there. Each stage of an enlarged brain allowed pre-sapiens to develop a better way of living, but it required the enlarged brain for each advance.

dhw: ...but it is not possible to perform new tasks without changing the brain. THAT is what “necessity” means here. We know that pre-sapiens brains expanded, and we know that new actions cause changes (or “modifications”) to the brain.
DAVID: Yes, complexity, plasticity and shrinkage, nothing more.
dhw: Plasticity is what allows the different modifications. Why do you refuse to accept that the addition of lots of cells and connections leading to enlargement is also a “modification”?
DAVID: Because the only facts we have in sapiens is shrinkage.

dhw: We are trying to explain enlargement, which is also a fact. You accept that new actions cause “modifications” to the brain. Enlargement is a modification. By all means reject the hypothesis on the grounds that we have no evidence (just as we have no evidence that your God enlarged the brain before the new actions were performed), but there is no reason to reject it on the grounds that enlargement is not a modification.

You are playing games with the word 'modification'. Enlargement and cortical complexity are specific modifications, which I think God supplied.