Introducing the brain: why so big? Part two (Introduction)

by David Turell , Monday, July 22, 2024, 17:00 (88 days ago) @ dhw

dhw: If he exists, he would have given our brains the ABILITY to change themselves in response to new requirements, as opposed to gazing into his crystal ball and preprogramming them 290,000 years in advance.

DAVID: But that is exactly what God did: provided a huge brain with the ability to complexify 290,000 years in its future!!!

dhw: Thank you for confirming my proposal. All additional cells at all stages of the brain’s history had the ability to complexify at any time, but none would have been added in order to hang around doing nothing except wait to be used.

dhw: Your agreement should also open the way to the possibility that the same applies to all of evolution: instead of a 3.8-billion-year-old book of instructions for every speciation, lifestyle, strategy and natural wonder, or countless ad hoc operations and courses on how to do this, that and the other, he might have given all cells the same autonomy as he gave our brain cells.

No one assumed the extra neurons were totally inert!!!

DAVID: Brain cells are very especially different types of cells. God designed evolution by Himself, not your weird secondhand design theory.

dhw: So your all-powerful God provided brain cells with the autonomous ABILITY to respond to future requirements, but he could not have done the same for other types of cell. Why not?

Neurons are very specialized cells, not equivalent to other cells.

Genome complexity

dhw: […] Your God would not have enjoyed our human development if he knew all of it in advance. So don’t you think an unpredictable evolution might possibly have been more enjoyable for him than knowing all the new species, lifestyles, strategies, natural wonders etc. in advance?

DAVID: You scurry back to your humanized fellow. How do you know God requires entertainment?

dhw: Nobody even “knows” if God exists! However, the above follows on directly from your belief that your God enjoys creating and it chimes in with your statement that your God “would not have enjoyed watching our development if he knew it all in advance”. It is not a matter of “requires entertainment”, as if somehow he’s needy. What is wrong with doing something because you enjoy it?

God may well 'enjoy' allegorically as we do in our way. Also, He may not,

“De novo”

DAVID: This makes rubbish of the Cambrian Explosion gap being de novo. Those marvelous animals used DNA from former Ediacaran's genomes. Nothing is de novo by your tight definition of evolution.

dhw: First of all, “de novo” creation in the Cambrian remains a theory.

DAVID: What theory? Isn't the gap real?

dhw: Yes, but the proposal that an unknown, eternal, sourceless mind created species “de novo” is just as theoretical as the proposals that the fossil record is incomplete, or that intelligent cells are capable of major jumps if new conditions require or allow them.

All theories are theories, never fact.

dhw: Secondly, what are you claiming here? All DNA consists of biochemicals. You can use the same materials to create any number of new things from the beginning. The question is whether there is a direct line from species to species, or in this case, from brain to brain. From hominids to homos, there is a continuous expansion, through the addition of new cells. Do you or do you not believe that our brains, together with their additional "layers of neurons", evolved from earlier brains?

DAVID: Sure, we evolved from earlier forms, which did not have five layers of pyramidal cells, a giant new phenotypical change.

dhw: Thank you. “De novo” means starting afresh from the beginning. But every expansion of our ancestral brains entailed the addition of cells that were not there before, and every evolutionary innovation (= something new) required changes to existing structures.

True.