Evolution and humans: big brain size or use (Evolution)

by dhw, Saturday, June 03, 2017, 11:10 (2728 days ago) @ David Turell

DAVID: You are positing complex thought when none existed to drive the enlargement.
dhw: How on earth do you know what our ancestors were thinking? The very fact that they used tools denotes highly complex thought. The earliest known throwing spears are 300,000 years old – long before the huge brain.
DAVID: Sure Habilis was throwing spears. Involves eye and muscle coordination. How much advanced cogitation was required. Not much. Chimps can throw stones at humans in zoos, So?

I am not talking about eye and muscle coordination but about technology, which requires highly complex thought.

World's Oldest Spears - Archaeology Magazine Archive
www.archive.archaeology.org/9705/newsbriefs/spears.html
QUOTE: “The spears show design and construction skills previously attributed only to modern humans. "They are really high tech," says Hartmut Thieme of the Institut für Denkmalpflege in Hannover, who discovered them while excavating in advance of a rotary shovel digger used in the mine. "They are made of very tough Picea [spruce] trunk and are similarly carved." Their frontal center of gravity suggests they were used as javelins, says Thieme.”

DAVID: Do you think Erectus can do calculus. Did erectus have our degree of consciousness. When did humans build habitations, grow agricultural crops, form cooperative societies? In the past 10-20,000 years. 200,000 years ago little of the mentation I just described existed.

This is why you keep contradicting yourself. It was consciousness and not the big brain that devised calculus, and I'll bet the brain densified as a result, just as it would have expanded as a result of consciousness wanting to produce sophisticated weapons. See below regarding the 180-190,000-year gap.

DAVID: Their tools were simple and their use lasted until 10,000 years ago. Where is the drive for enlargement?
dhw: What do you mean by the “drive for enlargement”? The drive is for improvement, though you prefer complexity. Enlargement is the result of the drive for improvement, which requires recognition of the need or opportunity for change and the decision to act accordingly.
DAVID: How does a physical object like a brain create a drive for improvement without envisioning what the new brain would look like in advance, to jump the gap in size. You want some type of internal drive, and all I logically see is external drive, God.

I did not say the brain created the drive for improvement! The drive for improvement or survival is what underlies all adaptations and innovations, including the brain and its evolution, just as you argue that the drive for complexity does the same thing. See also my comment under “whale changes”.

Dhw: As for homo sapiens not doing much for 190,000 years, I don’t know what they were thinking, or how much denser their brains became, or why they didn’t write books, invent computers, or mass produce chocolate. Perhaps they were too busy finding different ways to cope with their different environments. Or perhaps it just needed a few bright individuals with a bit of time on their hands to start asking questions nobody had ever asked before. What is your theory for the “delay”?
DAVID: Obvious. They had to learn how to use the big brain they were given. And once used more thoroughly, then it recently densified, as I said. Density indicates new intense use.

So your question is why it took 180,000 years for homo sapiens to use and densify his brain once it had reached its then optimum size. I don’t know, and nor do you, but I have speculated in the passage you have quoted. We know that thought densifies the brain, and you believe that thought is the product of consciousness, not of the brain. And so we have a logical progression: thought changes the size of the brain as it makes more and more demands. The brain reaches a size beyond which the head and body would not be able to cope. The fact that it then took 180,000 or 190,000 years for consciousness to require more changes does not mean that until then all thought was engendered by the brain! At each stage of increased volume, you still have consciousness using and changing the brain and not the brain using and changing consciousness. “Learning to use it” in your dualistic framework can therefore only refer to the process whereby consciousness acquires more and more information from experience and from the brain (through our perceptions), and so makes more and more demands on the brain, which initially responds by expanding, and recently responds by densifying. For 180-190,000 years the brain size was adequate for the needs of homo sapiens, but for reasons unknown his consciousness then came up with new ideas and new demands, and so instead of the brain responding by enlargement, it responded by densifying. This all fits in perfectly with the dualistic belief that it is the mind that uses the body/brain and not the other way round. And it is no problem for those who believe in God, because they can say it was God who designed the process and the apparatus in the first place.