Evolution and humans:big brain size and food supply (Evolution)

by dhw, Friday, June 23, 2017, 14:28 (2496 days ago) @ David Turell

DAVID:You've forgotten I have defined use as survival activities. Tool making, etc.
dhw: Thank you. In the context of enlargement, that is the clarification I have been waiting for. We agree that brain enlargement precedes survival activities such as tool making. My point is that the CONCEPT of the tool must precede the making, and conceptualization according to you is independent of the brain.
DAVID: I never said that. The level of conceptualization ability is directly related to the size and complexity of the brain, especially the prefrontal and frontal areas.

Concepts are ideas or thoughts, and whether simple or complex, your dualism argues that thought is independent of the brain. It is the materialization of thought that depends on the brain.

dhw: Therefore, just as the concept of reading demanded a rewiring of the illiterate women’s brains in order to be implemented, earlier concepts demanded enlargement for the same reason.
DAVID: Exactly backwards. Reading was done by the already enlarged brain. Rewiring results in densification and shrinkage of brain size.

Of course the brain was already enlarged, but reading required something new of the brain. Enlargement is over, and so the new method of implementing new concepts is densification through rewiring. The brain therefore responded to the new need by rewiring itself.

DAVID: You can't get around the fact that each bigger size is associated with more complex survival strategies. Under your idea, h. habilis wants to control fire, but can't figure out how to do it so he tries to think very hard and his brain suddenly jumps 200cc of frontal lobe. H. habilis doesn't know what he is missing by not being erectus! Habilis had no idea a spear was a better way to hunt. He did not have any inkling.

You can’t get around the fact that each bigger size is associated with the IMPLEMENTATION of more complex survival strategies, e.g. in the form of new tools. The strategy is the immaterial figuring out how to do it, which has to precede the doing, and the doing needs new material skills: the making and handling of the tools. Your brain doesn’t tell “you”/your conscious mind how to make and handle them. You/your mind work it out, and then get the brain and body to perform the material tasks. That is what requires changes to the brain. Just as the concept of reading required changes to the brains of the illiterate women – but in their case, densification instead of enlargement. Concept first, brain change second, realization of concept third.

DAVID: My brain is my gateway to my consciousness.
dhw: As you keep agreeing and forgetting, you/your consciousness are an inseparable entity, and as explained above, your brain is the gateway through which you/your consciousness get your body to realize new concepts.
DAVID: My self, my brain and my consciousness are seamless. I'm not forgetting.

But you are forgetting that according to your own beliefs, your self and your consciousness do the thinking (otherwise they could not survive into the afterlife), and so the brain is the gateway through which you/your consciousness translate thought into material action.

DAVID: Our current modern brain is filled with concepts and shrinking. Why isn't it enlarging per your hypothesis?
dhw: Because there has to be a limit to enlargement, or you will end up with an elephant’s head on an ape’s body. Once the maximum size was reached, the only way new concepts could be implemented by the brain was through densification. Shrinkage is merely a by-product of the efficiency of densification.
DAVID: Neanderthal brains were 150cc larger. We could have enlarged a little more. I didn't say we needed more enlargement. We shrunk with increased complexity and density, and that is one reason why I think evolution is over. You have just proved my point.

You asked why our brain is not enlarging. There has to be a limit. Densification took over from enlargement as the means whereby the brain increased its capacity to realize new concepts. I have suggested that shrinkage is a by-product of efficient densification. How on earth the densification of the human brain as a replacement for enlargement means that evolution is over I really don’t know. Let’s meet in a couple of billion years’ time to find out.