It was only eighteen months ago that I wrote a post titled “The implication of evolution after the dawn of agriculture.” At the time, I was startled by the idea that there may have been evolutionary change within the human population in the last four centuries. Also at the time I was highly impressed by Evolutionary Psychology evolutionary functional analysis, and the concept of the Era of Evolutionary Adaption.
Since that time I have learned more about how biology informs the social sciences. It appears that evolution is faster than I thought, and Evolutionary Psychology is weaker than I assumed.
Up until recently, the theoretical maximum speed for one gene to replace all other variations was one every 300 generations. It now appears the rate among humans is 2 every year. If this result holds up, this has important implications.
Two dynamics appear to be driving the acceleration of natural selection among humans: larger population size (more mutations are given a chance to rise up) and the even quicker evolution of culture (preventing the establishment of an equilibrium optimal genetic state).
Evolutionary Psychology is wrong because there is no species-wide “Era of Evolutionary Adaption.” Indeed, one wonders if the term “Era of Evolutionary Adaption” even makes sense. If it does, are EEAs of populations that had possessed agriculture for a very long time (say, the peoples of the fertile crescent, and Chinese and Indians of the great river valleys) far more agrarian than the EEAs of traditionally hunter-gatherer societies?
Further, as both cultural complexity and breeding population (both in numbers in and genetic diversity) vary historically, might one say that the Era of Evolutionary Adaption of Australian Aborigines is tens of thousands of years deeper in time than that of Indus River Valley dwellers?
Both the population of man and the culture of man have been growing at faster and faster rates. The implication of this is clear.
The 19th century saw more natural selection in our species than any other century, ever.
The 20th century saw more natural selection in our species than any other century, ever.
The 21st century will see more natural selection in oru species than any other century, ever.
And that’s not counting genetic engineering.