Brain complexity: learning new tasks (Introduction)

by dhw, Thursday, December 07, 2017, 13:20 (7 days ago) @ David Turell

DAVID: …the current human brain is an end point, which fits with my belief that it was/is God’s purpose to produce.
dhw: If the human brain is an end point, so are the duckbilled platypus, the skull-shrinking shrew and the whale.
DAVID: Very likely evolution is over is not an unlikely possibility.

You and I will never know. But I was merely indicating that “end point” does not mean “purpose”. The rest of your post is mainly devoted to your insistence that only after your God had enlarged the brain and skull were hominins, hominids and homos capable of thinking up new concepts and implementing them. You reminded me earlier of your dualistic belief that the brain is NOT the source of ideas, but clearly I am supposed to ignore the obvious contradiction when you say: “Only a larger more complex cortex can think of new more complex concepts.”

I am also supposed to ignore the contradictions I highlighted in my last post and which you have left out altogether in your responses. These simply repeat your belief that your God expanded the brain before it produced and implemented the new concepts, as if the repetition somehow removed the contradictions. Here once again is the section you have chosen not to respond to:

DAVID: You do not seem to understand my theory, A small brain is limited in the concepts it can develop. Pre-habilis could not understand the concept of spear. It took a habilis-sized brain to have the concept and implement it, both occurring in the same brain, not a subsequent larger addition.

dhw: I do not understand a theory that contradicts itself. Let’s forget pre-habilis, since you begin with habilis: “If habilis has an idea for spears, the idea is immaterial. No brain change.” So small-brained habilis has the idea. “Once he learns to knapp flint, attach the stone point to a wooden rod, and then practices throwing it with accuracy, there is no question that the brain has enlarged with all the muscle movement and visual coordination involved.” It is therefore the implementation that enlarges the brain, and so from then on we have a post-habilis with a larger brain. (You went on: “But then the brain complexified and shrank” – skipping to Homo sapiens and the Indian readers, when the brain had stopped enlarging.) According to you and to me, the concept comes first, the implementation then enlarges the brain until we reach sapiens, when it can expand no further. You have described the process perfectly. (My bold)

Do you now wish to rescind all the above? If not, how do you square it with your insistence that your God had to enlarge the brain BEFORE the idea (which did not change the brain) and BEFORE the implementation (which enlarged the brain)? In other words, why must the brain be enlarged before it enlarges itself?


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