Brain expansion: different theories about rapid expansion (Evolution)

by dhw, Wednesday, September 16, 2020, 10:29 (1527 days ago) @ David Turell

dhw: If they went on living in the manner they were born into, there was stasis, which for some reason is your main point. But hey presto, now you’re saying that bit by bit new concepts appeared. Please tell us what these new concepts were, prior to the sudden burst of new ideas (and apparently a slight reshaping of the brain) approx. 35,000 years ago. […]

DAVID: I am theorizing, not in specifics. […]

dhw: You said stasis was your main point. I keep asking why your God would have operated on the Moroccans 280,000 years before they needed their new brain. Now you theorize that there wasn’t stasis. Please make up your mind.

DAVID: You asked about new concepts, not stasis and I answered accordingly. Of course stasis.

280,000 years of stasis means they did nothing with their new brain. But you replied: “They didn’t do nothing. […] Bit by bit new concepts appeared”. That means there wasn’t stasis. So now we’re back to there WAS stasis. Fine with me, but I wish you would stop changing your mind.

DAVID: There was God's intervention. He designed the system. As for expansion of 200 cc of non-descript neurons with potential but no current function, tell me your natural driving force, because I don't see one except God.

dhw: My theory allows for God designing the system, which you keep agreeing functions WITHOUT God’s intervention! The natural driving force for expansion is NEW REQUIREMENTS (e.g. new ideas, ways of living, environmental changes) which the existing sized brain cannot meet without additional cells. Now please answer my question. [Why do you insist that the mechanism could not have complexified, reorganized and added more new cells in earlier brains?]

DAVID: And I answer stasis does not present new requirements as the Moroccans. New uses 35,000 years ago shrunk the brain! Your theory is inconsistent with fact.
And later:
Stasis in the Moroccans disproves your theory.

It does no such thing. Stasis relates to the period AFTER the expansion of the brain, when there were no new requirements. My theory concerns the CAUSE of the expansion. Nobody knows, but what we DO know is that the modern brain complexifies and in some areas expands in response to new requirements. This process, as you have agreed, takes place without any intervention from your God. And so I keep asking you why it is not feasible that the same process would have taken place in the past, with the brain producing more cells, as these were then required, though we do not know specifically what these requirements were. The shrinkage in the modern brain, as we have agreed, was due to the enhanced efficiency of complexification, which made some cells redundant. You have agreed to every single one of the above points.Now please answer my repeated and bolded question.

dhw (under “glial cells”): But the very fact that the brain is capable of adding neurons makes it feasible that earlier brains could have done the same.

DAVID: Your narrow view keeps ignoring the hippocampus, a center for memory which does add neurons to a small degree as we age and add memories. For you that means an entire brain can make 200 cc enlargements in evolution.

The hippocampus is integral to my theory! If the modern brain can add neurons, no matter how few, how does that demonstrate that earlier brains could not have added neurons?????