Tuesday, October 7, 2008

Human Evolution Has Ended, Says a Leading Geneticist

Steve Jones, a bright star in the world of genetics, gave a talk today entitled "Human Evolution is Over." The title is a bit deceptive because he goes on to forecast that "the future is brown" for the human race.

According to Jones, there are three key factors to evolution: Mutation, Natural Selection, and Random Change. The key factor in whether human offspring carry a mutation, it turns out, is the age of the father. Older fathers are the most responsible for passing on mutated genes.

It seems that in the human past a small number of community patriarchs would have children well into old age. This quote from the TimesOnline says it all: "'In the old days, you would find one powerful man having hundreds of children.' He cites the fecund Moulay Ismail of Morocco, who died in the 18th century, and is reputed to have fathered 888 children. To achieve this feat, Ismail is thought to have copulated with an average of about 1.2 women a day over 60 years."

The shift away from this kind of reproduction has and will continue to have a stabilizing effect on the genome. Stevens also cites the diminishment of natural selection (with 95% of children in industrialized nations surviving well into the reproductive years) and the re-combination of once geographically isolated genetic strains as mitigating against significant genetic change in humans for the forseeable future. (back)

(thanks to Rey-O for the Jack Kirby image)