Evolution and humans: more on learning to read (Evolution)

by dhw, Wednesday, November 07, 2018, 12:10 (36 days ago) @ David Turell

Dhw: It is also clear that the brain changes IN RESPONSE to new concepts and activities, and not in advance of them. I would extend this principle to the whole of evolution. The cells of the brain and the body respond to new demands and do not change in anticipation of them. However, it is also important to note that the plasticity of the brain does not explain how concepts originate, i.e. these observations do not solve the problem of the source of consciousness (materialism v dualism).

TONY: Except that the sympathetic nervous system engages in preparation for an event, and the alterations can become part of the programming and be considered via epigenetics.

Sorry, but I’m not sure what you’re referring to. How does the “sympathetic nervous system” prepare for something it knows nothing about? Once the brain/body has changed, certainly it will be programmed to perform the new tasks, and I have no doubt that epigenetics plays a major role in evolution.

DAVID: The larger brain had new areas that could be adopted for new uses, present at the time of newly found uses and not in anticipation of them.

Yes, and in view of my comments below and to avoid repeating our past discussions on the subject, I’d better add that once the brain/skull had reached its optimum size, new uses were implemented through complexification, not expansion, and the efficiency of this has even resulted in a degree of shrinkage.

Dhw (to David): You are simply repeating the fact that the brain is plastic. All adaptation requires plasticity of some kind! And if cell communities were not able to undergo change, evolution would never have taken place – regardless of whether your God fiddled with them or they fiddled with themselves. Your interpretation of evolution, however, is that your God changed the cell communities in advance of the conditions that required or allowed the changes. The article shows that the cell communities that make up the brain changed in response to new demands, not before them.

DAVID: The brain areas that assumed new duties already existed and were given the ability to change as necessary when they were created. Why do you interpret that fact differently?

I don’t. Of course the ability to change must have been present from the beginning! Otherwise evolution could not have taken place. But that does not mean your God made the changes in advance of new demands! I am referring to your insistence that your God changed the pre-sapiens brain before it could conceive the spear, changed legs into fins before the pre-whale entered the water, changed the anatomy before pre-humans descended from the trees – i.e. that every evolutionary innovation was planned in advance of changes in conditions. The brain like all other cells/cell communities RESPONDS to new conditions; there is no evidence that cells/cell communities change in anticipation of new conditions.

DAVID (under “Introducing the brain”): Rodent research makes the point that mental ability is increased by vigorous exercise:
https://www.the-scientist.com/features/this-is-your-brain-on-exercise-64934

But it also makes the point that exercise CHANGES the brain:

QUOTE: Researchers have long recognized that exercise sharpens certain cognitive skills. Indeed, Maejima and his colleagues have found that regular physical activity improves mice’s ability to distinguish new objects from ones they’ve seen before. Over the past 20 years, researchers have begun to get at the root of these benefits, with studies pointing to increases in the volume of the hippocampus, development of new neurons, and infiltration of blood vessels into the brain. Now, Maejima and others are starting to home in on the epigenetic mechanisms that drive the neurological changes brought on by physical activity.

The point could hardly be clearer. It is “exercise” that changes the brain, even to the extent of enlarging some parts and developing new neurons. If we go back into the past, the same process must have taken place in pre-humans – namely, that “exercise” in the form of implementing new concepts would have changed the brain, and the resultant increase in volume would have required a larger skull to house the larger brain. Can you fault the logic?


Complete thread:

 RSS Feed of thread

powered by my little forum