2. A fair fraction of the recent evolutionary change affected brain & axon growth. For example, you see new versions of SLC6A4, a serotonin transporter, in Europeans and Asians. There's a new version of a gene (DBA1) that shapes the development of the layers of the cerebral cortex in east Asia.
3. There is considerable psychometric evidence of group differences consistent with the recent neurological changes (Ashkenazi Jews consitently average 2/3 of a std deviation above Europeans. East Asians have a group average of about 103, Europeans 100) Rushton, J.P. and Jensen, A.R. (2005). Thirty Years of Research on Race Differences in Cognitive Ability. Psychology, Public Policy, and Law, Vol. 11, No. 2, 235-294. [easily located on the web]
4. Also, see 'A Farewell to Alms':
The study of wills reported in A Farewell to Alms implied that economic
competition could change the genetic composition of the English population over
time. This study of rare surnames shows that indeed economic success in 1600
by a man could permanently increase the relative frequency of his surname, and
by implication of his genes. This does not demonstrate that these genetic changes
had significant impacts in changing the behavior of the average person in England
by 1800. But Clark (2008) shows that economic success in modern societies has
at its roots a significant genetic component."