Introducing the brain: half a brain is just fine (Introduction)

by David Turell , Wednesday, March 11, 2020, 14:28 (1507 days ago) @ dhw

DAVID: Again a total distortion to save a pet theory. The first assumption has to be that our brain has processes developed from past brains and uses them in more complex ways.

dhw: Yes indeed, and since our modern brain follows processes of complexification and expansion (though now only on a minor scale) in response to – but not in anticipation of – new concepts, desires, plans etc., it is perfectly logical to assume that past brains did the same.

Except for your 'in anticipation', we agree.

DAVID: Your theory that the brain stopped enlarging because of anatomic size considerations is simply a wild guess, lacking any evidence for the point.

dhw: If the brain had continued to expand, we would have had elephantine heads! Expansion had to stop somewhere! That is not a wild guess – it is a logical assumption. What is your explanation for the end of expansion and the takeover by complexification?

I gave you the conversion of cc to ounces. The biggest enlargements were less than seven ounces. 'Elephantine' is pure silliness. We got to this final point in small steps. It isd all we need and it shrank from increased uses.

DAVID: Our brain arrived about 315,000 years ago and really began its 'implementation' process (your concept as to how the brain is affected) most actively with language 50-70,000 years ago, and as more an more 'implementation' has occurred in the past 35.000 years it shrunk 150 cc. (about five ounces) That is the factual evidence we have to work with, and we both note tiny enlargements in heavily used regions. That is a logical change in our brain.

dhw: Yes, both complexification and enlargement come from usage, not in anticipation of usage. The exact opposite of your theory that your God enlarged the brain before conceptualization and implementation. And it is not implementation that has shrunk the brain, but the fact that the efficiency of complexification has made a certain amount of the brain’s capacity superfluous. All perfectly logical. (my bold)

The bold is so obviously backward in its misuse of the facts. Sapiens arrived with a barely used brain and then employed your implementation process with in the end shrinking.

DAVID: In fossil brains the usage was never as intensive as today yet we know 200 cc jumps in volume occurred. Your strange theory does not hold water in any sense, and your paragraph above offers nothing to save it.

dhw: Our brains are the accumulation of all past concepts and all past expansions plus our own new concepts. That is why I propose that the brain eventually had to stop expanding, as above, and complexification took over, and was so efficient etc. etc. ad nauseam.

And I say this last brain was given the capacities to not need any further expansion.

DAVID: Please remember I have no knowledge of God's reasons.

dhw: You believe your logical God did it, and you can’t think of a single reason why he would have done so.

Pounding same dead horse. I don't look for His reasons. No need.

DAVID: Of course I agree with shrinkage from complexification. My argument and belief based on facts has never changed. Heavy usage shrinks modern brains.

dhw: Heavy usage causes complexification and minor enlargement, and once more: complexification is so efficient etc. ad nauseam. If an organ or part of an organ is no longer required, it is not unnatural for it to disappear. You could hardly have a more logical explanation. But you think your God made our brains larger than necessary and preprogrammed or dabbled shrinkage, and you have no idea why.

Nor do you.

DAVID: Light use in habilis and erectus saw brains make large jumps in size. The comparisons don't fit, unless God as an agency is at work. Then of course you can ignore all the facts and daydream as an illogical distortion of them.

dhw: Please note that in my theory it was a new "heavy use" that caused the brain to expand - just as it does today, though on a lesser scale.

Silliness again. Our overall brain shrank. Don't try to hide a major point.

dhw: Now please tell me what facts I have ignored or distorted, what additional facts you have to support your theory of divine preprogrammming or dabbling in advance of the need for expansion, and please do make an effort to understand why your God might have preprogrammed or dabbled shrinkage as well. You keep saying he thinks logically, but how do you know that if you can't understand his logic?

All we have is fossils, with differing brain sizes, and artifacts that advance as size increases. Archaeologists simply observe this and assume the larger size allowed the advances. I don't know why God allowed a bigger brain before it shrunk. Do you? But those are the facts we have, and you can't understand His logic either. Your obvious point is if God did something illogical, He doesn't exist. My logic about the bigger size at first: it contained early regions that helped in complexification and then left when the job was over. I will not apply that as God's actual thoughts.