Evolution: more genomic evidence of pre-planning 2 (Evolution)

by David Turell , Wednesday, April 07, 2021, 19:05 (1324 days ago) @ dhw
edited by David Turell, Wednesday, April 07, 2021, 19:16

dhw: How huge is “huge”? [...]

DAVID: Our current brain averages 1,200 cc+, so our enlargement of 200 cc is at 20% of the last size, quite a huge addition for a previous one lasting a couple millions of years.

dhw: Three websites that disagree:
Homo erectus Vs. Homo-Sapien: General Difference - Viva ...
https://vivadifferences.com/homo-erectus-vs-homo-sapien/

I've looked at this website. It says the largest erectus brain size reached 1,200 cc while sapiens was 1,350 cc. Also note the illustration of skull shape, and the small size of the frontal lobe area of erectus. You keep ignoring my point that it is the size of specific areas and their specific functional capacities that really counts.

This site tells the real story:

http://www.handprint.com/LS/ANC/brain.html

"Brain function is best inferred from the relative size and form of different brain areas. The erectus brain shows the characteristic "football" shape of hominid brains from Homo ergaster on up. This shape arises principally from a tandem expansion of the frontal (F) and occipital (back, O) lobes in relation to the rest of the brain.

"Increases in the frontal lobe appear in Australopithecus africanus and all subsequent hominid brains. This expansion signals a radical change in frontal lobe function, away from olfactory analysis toward complex abstract processing. In humans, the frontal lobes contribute heavily to social behavior and the planning of future actions.

"Terrence Deacon proposed that the frontal lobe is the developmental and cognitive key to human language ability. If so, frontal lobe expansion implies that hominid language abilities may be quite old, perhaps predating the toolmaking abilities that appear in stone artifacts at least 2.4 million years old. Language does not mean spoken language necessarily, but use of a syntax to interpret meaning from the order and form of two or more signs.

"The modern brain shows its greatest expansion in the middle parietal lobes (P). This expansion accounts for the rounded shape of human skulls in contrast to the flattened "football" form of skulls in earlier species, including Neandertals. Technological, abstract and computational thinking seems to arise in the parietal lobe, and this is the area of greatest relative difference between the two outlines. We might associate this parietal expansion with the appearance of remarkably diverse and refined tool cultures, and spoken language, about 90,000 years ago.

I'll admit I've simplified our discussion by using size only at times but what expands and what it functionally does is much more to the point. Your response?