Greg Cochran blogs: “From time to time I have marveled at how the Left has changed over the years – basically, from steel-driving commies to gender-bender commies. Which leads me to wonder what would happen if, via some mechanism built of ivory and twisted crystal rods, they were ever to meet.”
Gregory M. Cochran (born 1953) is an American physicist, author, and anthropologist. He is a research associate at the anthropology department at the University of Utah. He is co-author of the book The 10,000 Year Explosion.
In opposition to what he sees as the ‘conventional wisdom’ that civilization has been a static environment which imposed stabilizing selection on humans, Cochran, along with like minded anthropologists such as John D. Hawks, contends that haplotype and other data indicate the selection of genes has been strongest since the advent of farming and civilization.
Main article: Ashkenazi Jewish intelligence
Cochran and co-authors Jason Hardy and Henry Harpending suggest that the high average IQ of Ashkenazi Jews may be attributed to natural selection for intelligence during the Middle Ages and a low rate of genetic inflow. Cochran et al. hypothesise that the occupational profile of the Jewish community in medieval Europe had resulted in selection pressure for mutations that increase intelligence, but can also result in hereditary neurological disorders.
Cochran believes an evolutionary perspective suggests that the proximal cause of homosexuality must be an infection. Cochran does not suggest that an infectious agent that causes homosexuality is spread by homosexuals. The premise is that homosexuality reduces the number of offspring and would lead to the genes carried by a homosexual person to be progressively eliminated over generations. Cochran maintains that the observed level of prevalence of exclusive homosexuality (3 to 4 percent of men and 1 to 2 percent of women in the United States) means genes cannot be the cause of homosexuality. This argument is based on natural selection, the fitness cost of genes ‘for’ homosexuality being too great for its occurrence at a frequency above that of random mutation (~ 1 in 50,000). The argument assumes that evolution would have largely eliminated homosexuality related to non-infectious environmental causes, except novel ones.