Wednesday, March 28, 2007

Science of Ugliness

The BBC has an interesting story about a potential explanation to a paradox of evolution. The paradox to be put bluntly is that there are still ugly people around, if females select their mates on the basis of looks then over time evolution should favour the genes that give rise to better looking people. Eventually everyone should be beautiful. Some of that noisy band of idiots that try to refute evolution like to use this argue that evolution is false.

This "paradox" seems to me to be inherently wrong anyway, it makes the assumption that women have always been free to choose who they marry, which of course is blatantly not the case. It also of course neglects the impact of women choosing to marry for reasons other than looks, money being the obvious example.

Regardless of this, the researchers Professor Marion Petrie and Dr Gilbert Roberts of Newcastle University believe they have found a mechanism that explains why we are not all models.

The scientists claim that since genetic mutations can occur anywhere in the genome, some will affect the DNA repair kit possessed by all cells.

As a result, some individuals have less efficient repair kits, resulting in greater variation in their DNA as damage goes unrepaired.

This variation leads naturally to a variation in looks, it probably has other effects which are more beneficial to the population, like providing a wide range of mutations some of which could be useful in fending off disease for example. In other words it looks like there is a balance in a population between everyone looking good and having a wide enough variation in the population to be able to resist changes in the environment. Exactly as natural selection would predict.