[...] An analysis of endocranial casts suggests that while Homo sapiens brain size was comparable to that of humans around 300,000 years ago, brain shape evolved gradually until reaching present-day human variation between about 100,000 and 35,000 years ago:
Human brains gradually evolved from a relatively flatter and elongated shape — more like that of Neandertals’ — to a globe shape thanks to a series of genetic tweaks to brain development early in life, the researchers propose January 24 in Science Advances.
A gradual transition to round brains may have stimulated considerable neural reorganization by around 50,000 years ago. That cognitive reworking could have enabled a blossoming of artwork and other forms of symbolic behavior among Stone Age humans, the team suspects. Other researchers have argued, however, that abstract and symbolic thinking flourished even before H. sapiens emerged (SN: 12/27/14, p. 6).
The evolution of modern human brain shape (open, DOI: 10.1126/sciadv.aao5961) (DX)
(Score: 0) by Anonymous Coward on Saturday January 27 2018, @02:44PM (3 children)
That kind of thing happens in plants and animals all the time, it's called an epigenetic adaptation. If yuppie busy has to activate a piece of DNA to better survive, it will definitely try to activate it in children too.
(Score: 1) by khallow on Saturday January 27 2018, @06:27PM (2 children)
Er, no. That kind of thing doesn't happen all the time. Epigenetic adaptation still requires a mechanism for going from learned behavior to actual chemical exchange with the developing fetus. That doesn't exist.
(Score: 1, Interesting) by Anonymous Coward on Saturday January 27 2018, @10:13PM (1 child)
Epigenetic changes have been observed to be hereditary in many plants. The sex of many animals can be predicted based off environmental factors. There is a lot of solid evidence pointing towards intentional adaptation towards fitness based off environmental factors, and no reason to believe it wouldn't occur in humans. In fact, homosexuality has been theorized to be a reaction to population levels, and the evidence is compelling.
(Score: 1) by khallow on Sunday January 28 2018, @04:01AM
Not a learned behavior.