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

by David Turell , Wednesday, November 01, 2017, 17:33 (2577 days ago) @ dhw

DAVID: Because the advances could not occur unless the abilities were available. The ability to have upright posture preceded the descent from the trees. Lucy walked upright but still had long muscular arms to show she also used the trees.

dhw: Perhaps when her species left the trees and began to walk upright, their long arms were still useful and enabled them to continue spending time in the trees. Isn’t this just as likely as your God suddenly dabbling with a bunch of apes up in the trees, fiddling with their bodies, and telling them to go walk on the ground except when they felt like going back up the trees?

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

DAVID: The only response we know about brain use is to shrink not enlarge!

dhw: Nobody knows why the brain expanded. But since we know the brain alters its structure (rewiring) IN RESPONSE to demands made on it, why do you find it illogical to hypothesize that expansion was also the result of response to demand, and shrinkage came about when rewiring took over from expansion?

Because the only event we know of in intense use of a brain is shrinkage. You are extrapolating in the opposite direction with no evidence.

DAVID: “…expanding hominid brains before there is any reason for them to be expanded" is God allowing them to get to a more advanced mental status.

dhw: An extraordinary claim for a dualist, who believes that the mental state does NOT depend on the brain. If the “soul” exists, it would provide the advanced thinking, and if the existing brain could not implement the “soul’s” new ideas, it would have to expand/complexify. You have it the other way round: the brain expands/complexifies and then apparently says to the “soul”, “Now I'll be able to make the tools you haven’t yet thought of.”

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.

DAVID: In my view God creates advances by 'suction' pulling advances forward by design. You believe in 'pushing' from behind. Two very different interpretations which will not be resolved, since you are so fixed upon avoiding God as a necessary designer.

dhw: At no time have I ever offered any hypothesis that does not include the possibility of God as a designer. I am not an atheist. You reject my theistic hypothesis because you are “fixed upon” a personal interpretation of your God’s intentions, even though it does not explain most of evolution’s history.

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

DAVID: Yes, environmental changes foster epigenetic adaptations. Species change require advanced planning and is a process we do not understand. but it is obvious planning and design are required. Again we have two very different views of the requirements for new species to appear. It cannot be a bit-by-bit stepwise process. The fossils do not show it as Gould repeatedly pointed out.

dhw: My hypothesis allows for saltations as well as “bit-by-bit” processes such as the eight-stage whale and the multi-staged history of hominins, hominids and humans.

Bit-by-bit only implies tiny changes, adaptations not speciation!

dhw: I agree that we do not understand the process, and I agree that design is required. I do not agree that the design has to be planned in advance. Epigenetic adaptations require design, which is carried out by the cell communities RESPONDING to environmental changes. That is clear evidence of a mechanism (possibly designed by God) for physical changes as a response. There is absolutely no evidence for physical changes in anticipation of environmental changes that have not yet happened.

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