Big brain evolution (Evolution)

by dhw, Friday, January 05, 2018, 17:50 (2512 days ago)

This is the second post I found while searching for the dualism/materialism one, and it seems to me to sum up a great deal of what we have been discussing under "learning new tasks". It clearly followed on from an article proposing that random mutations caused brain expansion, but my concern was to develop a far more purposeful hypothesis, and I still think its logic is convincing. I posted it under "Different in degree or kind: big brain evolution" 18 December 2016 at 14:03".

These researchers use mutations in Darwin’s sense of random changes, but if we go back to my hypothesis reconciling dualism and materialism, perhaps there could be an ongoing feedback here. Something triggered a new awareness. Perhaps a forced descent from the trees. One can imagine an isolated group of tree-dwelling apes whose habitat is destroyed by disease. Tree-climbing is a vertical exercise. Maybe verticality proved to be an advantage down on the ground, and the change itself sparked new awareness. (I realize this is pure speculation, but I am not satisfied with serendipity, or with divine preprogramming, or with divine, step-by-step dabbling – if David’s God wanted sapiens, he could have produced sapiens.) The adjustment to permanent life on the ground would have required experimentation. We know that chimps, for instance, use tools, but perhaps with this particular group of our chimp-like ancestors, the intelligence needed to use tools was supplemented by other factors, such as the need to find new ways of protecting themselves against predators, since their trees had disappeared. What I am looking for is the spark that would have enhanced awareness.

Once the spark is lit, the next step is the effect of thought on matter: the brain responds to exercise; new activities demand new connections between brain and muscles, and new forms of communication between members of the group. One thing leads to another in a perfectly logical chain of developments. The brain engenders thought, and thought in turn develops the brain. This ties in with the researchers’ observation that our intelligence is bigger than our brain, and also with the theory of emergence, that the sum is greater than its parts. Add the theory of convergence, and you have similar patterns emerging elsewhere, to explain how different “species” of hominin may have arisen and with migration may even have interbred (as it is now believed that Neanderthals and Sapiens did). Once we have that extra degree of awareness, the whole process is self-advancing, as one observation leads to another, and each observation engenders new needs and actions and physiological adjustments. In brief, the brain engenders thought, and the extraordinary levels of consciousness that distinguish us from our fellow animals are the result of new needs engendering new thoughts which, in turn, engender physiological adaptations, including the expansion of the brain. (PRESENT COMMENT: to this we must add the complexification that took over once the brain had stopped expanding.)

What we do not know is the spark that lit the fuse for this chain reaction. That, however, would be the only instance of “serendipity” – productive good luck, in contrast to the bad luck that has left 99% of species extinct. Variability within species is enough to explain why some groups of primates remained the same while others advanced. And there is no exclusion of the God theory, since this is a very late chapter in life’s history, and deals only with the origin of humans, and not with that of life and consciousness.