Evolution and humans: big brain size uses energy (Evolution)

by David Turell , Thursday, November 02, 2017, 19:03 (2576 days ago) @ dhw

DAVID: That comment agrees with my concept. Of course they used the trees and ground at first with their changed bodies.

dhw: There is no agreement. My concept is that they descended from the trees, which led to their upright posture, though they retained their long arms. Yours has God preprogramming or dabbling the changes before they descend. The concepts are directly opposed.

No self-respecting ape type leaves the trees without a reason. There is evidence of upright posture alterations in the spine 23 million years ago, in preparation for the descent. If they came out of the trees as you propose, there should be more fossil evidence of the pelvic alterations required. There are none. The speciation gap exists.

DAVID: […] the only event we know of in intense use of a brain is shrinkage. You are extrapolating in the opposite direction with no evidence.

dhw: You continue to ignore the other event we know of, which is that the brain complexifies (rewires ) IN RESPONSE to new tasks imposed on it (e.g. the illiterate Indian women who learned to read). Shrinkage would have begun after the brain had reached optimum size, and complexification had taken over.

You keep skipping over in your reasoning the fact that shrinkage is only seen after a brain is enlarged, although you recognize the sequence. The cause of enlargement is not proven by that observation. A particular size is reached with gaps in the fossil story. It is not epigenetic, while the shrinkage is.

DAVID: I'll go back to computers: an advanced computer allows production of advanced artifacts, which a lesser computer cannot. The soul uses the early brain to create complexity as far as that brain allows. With the soul in charge the next more complex brain allows more complex creations. Yes, it is the other way 'round from you.

dhw: Your computer analogy clearly showed that advanced computers were designed IN RESPONSE to the need for more complexity, not in anticipation of such a need. Your dualistic “soul” does indeed use the brain to implement its ideas. If the existing brain does not allow implementation, then it needs to expand (former times) or complexify (modern times). Why would it expand/complexify in anticipation of ideas that have not yet been thought of?

My point. Simply, the brain can't by itself. It needs God as an outside agent to do it.

DAVID: Thanks again for offering God lite, and my theory does provide for the bush of life.

dhw: I don’t know what you mean by God lite. A God who invents a mechanism that creates an evolutionary free-for-all with the option of the occasional dabble is just as much a God as one who designs every single innovation, lifestyle and natural wonder so that he can have a relationship with one particular species.

God lite is your way of introducing God by having Him create a semi-autonomous mechanism which is still God in action. He dabbles!

DAVID: Environmental changes are only one of many reasons for speciation. Speciation is planning in advance. Epigenetic modifications are not speciation.

dhw: NOBODY knows how speciation occurs, and I keep agreeing that epigenetic modifications are not speciation. But they are proof that there is an autonomous mechanism which can change the bodies of organisms. The question is whether it is capable of major innovations as well as minor changes. Speciation (broad sense) is not planning in advance. Speciation is major changes to the anatomy. It is you who insist that they must be planned in advance, as opposed to being responses to the challenges and opportunities offered by the conditions in which organisms find themselves.

Yes I insist as well as my ID friends.