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

by David Turell @, Wednesday, November 07, 2018, 18:21 (1985 days ago) @ dhw

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.

dhw; 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.

Stepping in for a bit of medical education. The sympathetic nervous system is part of the autonomic nervous system:
"The sympathetic and parasympathetic systems are both components of the autonomic nervous system of the brain. They act in collaboration with each other to sustain the body’s homeostatic state."
Obviously the sympathetic system knows what is happening.

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?

dhw: I don’t. ... 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.

You stay blind to the fact that a big brain appeared before all the new concepts were developed. See my entry today on how fungus changed the Earth, and was prepared to do so in advance!

DAVID (under “Introducing the brain”): Rodent research makes the point that mental ability is increased by vigorous exercise:

dhw: 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?

Perfectly logical, with one huge exception: we have no idea why the brain grew so large from its smaller size before it was used as in today's humans. The mice did not have exploding skulls in this study, only plastic alteration of the brain that already existed. And we know aht plasticity shrinks existing brains

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