Human evolution; "Little foot's" brain (Introduction)

by dhw, Wednesday, December 19, 2018, 10:38 (1952 days ago) @ David Turell

QUOTES: The study also has shown that the vascular system in Australopithecus was more complex than previously thought, which raises new questions on the metabolism of the brain at this time. This might be consistent with a previous hypothesis suggesting that the endocranial vascular system in Australopithecus was closer to modern humans than it was in the geologically younger Paranthropus genus. (David’s bold)

Given its geological age of over 3 million years, Little Foot's brain suggests that younger hominins evolved greater complexity in certain brain structures over time, perhaps in response to increasing environmental pressures experienced after 2.6 million years ago with continuing reduction in closed habitats. (dhw’s bold)

"'Such environmental changes could also potentially have encouraged more complex social interaction, which is driven by structures in the brain," says Beaudet. (dhw’s bold)

DAVID:Little Foot is obviously a transitional form.

Yes, she provides yet more evidence of common descent.

DAVID: But note my bold about the somewhat advanced vascular system. Advanced planning by God?

If so, then why would he have bothered to introduce the less advanced system later on?

DAVID: Social relations were also dictated by hunter-gatherers groups which had to form for survival as small groups cooperation provided food and protection. Brain plasticity would have made brain changes as socialization progressed.

Delighted to see you acknowledging that this area of evolution was dictated by the survivability which you tell us plays little or no role in evolution. But I’m interested mainly in the two sections I’ve bolded. Increasing environmental pressures demand increased brain activity if the hominin is to survive – i.e. brain change is in response to new requirements. But the second bold suggests the reverse – that it is the brain that drives new activities. This is a contradiction. I would support the first bold: that environmental change requires new activities, and it is these activities that change the brain.