Brain expansion (Evolution)

by David Turell , Tuesday, August 04, 2020, 20:01 (1361 days ago) @ dhw

DAVID: Repeat, as always. The soul can only work with the brain it is given and its level of complexity which controls the level of thought complexity allowed. The brain will respond by complexification of areas used and may have tiny areas of enlargement with extra neuron networks from intense use. But soul's thought does not cause large expansion as seen in fossils.

dhw: A bit of wool here, but the key part is your agreement that the dualist’s brain RESPONDS to the thoughts of the dualist’s soul. Your final sentence is another way of saying that the same process of brain responding to thought did not apply when larger expansion was required. You do not and cannot give any reason for this authoritative declaration.

Crossing the theory boundaries, I am with God as engineer, and you wish for natural causes. I see no natural support in sapiens history.

DAVID: You've changed emphasis. Your original theory about expansion was that an earlier brain had a brilliant idea which forced an expansion so it could be implemented. I pointed out that the Moroccans came with no new artifacts, and the long following stasis disproved your theory. That makes sense to me, while your original theory doesn't fit sapiens history.

dhw:How have I changed emphasis? I have never said that the only possible brilliant idea was a new artefact!!!

I know what I remember was your original theory; artifact or not, what you wrote was an important new idea that had to be implemented so it caused an enlargement to occur for the actual implementation.

dhw: Once more: NOBODY KNOWS the cause of expansion, but we both took the spear as a concrete illustration of the process. Out of interest, I’ve looked at the early stages of this discussion, under “Introducing the brain: half a brain is just fine.” On February 19 I bolded the following: “pre-sapiens brains expanded when the capacity was too small to meet new requirements (e.g. the implementation and usage of new means of survival). The expanded brain would suffice for so many thousands of years until it could no longer cope with more advances, and so it expanded again.” What part of my theory has changed?

In different words you have quoted exactly my impression of your theory was/is. Talk of woolliness!!!

dhw: As for the Moroccans, yet again: we don’t know what caused the expansion, but whatever the cause, once again there was a long period when there were no further new ideas or experiences or changes in conditions that required any major change in the brain. This is entirely consistent with my theory.

No it isn't. Your theory requires a new event activity (style of life) or article to appear with them. It doesn't.

DAVID: What don't you understand about the word 'reorganized'? It describes the complexification and helps explain the shrinkage as unnecessary neuron circuits are dropped.

dhw: Then we agree. You claim that your God had to dabble in order to "reorganize" the sapiens brain, but complexification and minor expansion can be explained as part of the ongoing development from one brain to the next. The basic structure remains the same. (Shrinkage was simply the natural result of complexification making certain cells redundant – no dabble required there either.)

Complexification is a process God gave early homo brains as part of brain enlargement. Not a dabble. What is your point?

DAVID: I'll stick with God running evolution as we know it.

dhw: […] why do you keep harping on about “God running evolution”, as if your God could not possibly have run evolution by designing a mechanism that enabled the brain to expand as well as to complexify without his intervention?

DAVID: See my thoughts about your expansion theory above. If your idea is true under the deluge of ideas we sapiens have had our brain should have expanded, but complexification made it shrink.

dhw: And that is why I have emphasized the fact that if our brains had continued to expand, we would have finished up with elephant-sized heads. And so it had to stop expanding. You couldn’t and clearly still can’t grasp that obvious fact. Complexification took over, and was so efficient that the brain shrank.'

As I've stated over and over, God ran and designed everything in homo evolution. We are obviously brilliant without ever reaching elephant head size. We didn't ever need to. Elephants have much bigger brains, are bright animals, but their neuron networks are not equal to ours. It is complexity, not expansion that is the important concept. As a result, only slight expansion is ever necessary.