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

by dhw, Saturday, January 27, 2018, 13:32 (2490 days ago) @ David Turell

dhw: Your hypothesis leaves you with the same contradiction you simply cannot resolve: you say your God expands the brain, and only then can the hominin think of something new, although thought according to you does NOT depend on the brain.

DAVID: Must I repeat! The s/s/c uses a more complex cortex for more complex thought [...] Brain does operate without s/s/c running the show.

Since s/s/c uses the brain, I presume you mean brain does NOT operate without s/s/c running the show. You don’t need to repeat the formula that I keep questioning. We are discussing two stages: 1) concept; 2) implementation. According to you the s/s/c/ does the thinking. Yes or no? It uses the brain to implement its thoughts. Yes or no? If the answer to both questions is yes, take the one example we know for sure: concept is reading and writing; implementation leads to more complex brain. The illiterate women’s brains did not rewire themselves BEFORE the implementation of the concept. Continued as follows:

Dhw: New applications and implementations change the brain. The brain does not change beforehand.

DAVID: We don't know your declarative sentences I've bolded are at all true. All your hypothesis.

This is the only sentence of mine that you bolded, and you are right. It is a hypothesis, which can be extrapolated from known processes. Your argument that God expanded pre-sapiens brains and only then were they able to think of new concepts is also a hypothesis. It contradicts the dualistic hypothesis that thinking is not done by the brain but by the soul.

dhw: The nub of the problem is that you keep conflating two separate stages of my hypothesis: 1) The new sapiens size resulted from the implementation of a new concept conceived by the pre-sapiens “soul”, as vividly described in the first section of this post. 2) From then on, the brain could not expand any further, so yes indeed, the new sapiens size preceded all the new concepts that followed, as conceived by the dualistic soul, but implementation took place through complexification, which apparently also caused reshaping as well as shrinkage. So each pre-sapiens expansion resulted from new concepts that exceeded current capacity; from sapiens onwards, new concepts resulted in complexification with shrinkage and reshaping.

DAVID: You've agreed above that presapiens brain could have compllexified during implementation, now you have withdrawn it. My point is the same stage of brain development gets the concept and does the implementation. The next larger stage develops the concept and implementation, which is the only way the artifacts fit the fossil history. Size first, use second.

I have not withdrawn it. The same stage of brain development may well have implemented lots and lots of concepts through complexification, but eventually concepts arose which the existing brain could not implement. Then the capacity had to be expanded, and the same process continued until stage 2) described above. This is also the case in your own hypothesis: implementation could not take place unless the brain expanded. However, in your hypothesis, God steps in and expands the brain BEFORE the relevant new concept (or if you like, before the innovative development of existing concepts) can be thought of. That means the thinking depends on the size of the brain – the exact opposite of the dualistic view that thinking is done by the soul. As for fossil evidence, the artefacts appear alongside the new sized brain. They can only appear when the brain has finished expanding, which in my hypothesis it does BY IMPLEMENTING the concept. In both hypotheses, therefore, the appearance of the artefacts coincides with the appearance of the expanded brain.