HENRY

Eureka Alert says:

Researchers believe they have solved a mystery that has puzzled evolutionary scientists for years… if ‘good’ genes spread through the population, why are individuals so different?

…and the answer to this lek paradox is in a paper published in the latest Heredity, Sexual selection and the evolution of evolvability :

Here we show that sexual selection can have an effect on the rate of mutation. We simulated the fate of a genetic modifier of the mutation rate in a sexual population with and without sexual selection (modelled using a female choice mechanism). Female choice for ‘good genes’ should reduce variability among male subjects, leaving insufficient differences to maintain female preferences. However, female choice can actually increase genetic variability by supporting a higher mutation rate in sexually selected traits. Increasing the mutation rate will be selected against because of the resulting decline in mean fitness. However, it also increases the probability of rare beneficial mutations arising, and mating skew caused by female preferences for male subjects carrying those beneficials with few deleterious mutations (‘good genes’) can lead to a mutation rate above that expected under natural selection. A choice of two male subjects was sufficient for there to be a twofold increase in the mutation rate as opposed to a decrease found under random mating.

Posted on March 29th, 2007 by Simon Greenhill