gillianren wrote:I don't think the gene would work its way out of the population entirely as long as redheads/those who carried the gene kept on breeding. I mean, sure, it's recessive, but that still, if I remember my high school biology properly, gives a 1/4 chance for any child to carry the gene. besides, since so many people (myself included!) find red hair more attractive, wouldn't they have a better shot at breeding anyway?
The probability of a child carrying at least one copy of the gene is p*(2-p), where p is the proportion the gene makes up in the population.
No particular reason for the gene to die out, unless it is "inferior," in the sense that it negatively affects the carrier's chances of surviving/breeding. Even then, an "inferior" gene can survive if the heterozygote (with one "inferior" gene and one not-inferior gene) has improved survivability. This is the case with the gene that causes sickle-cell anemia. It is recessive, and if you have two of them, you die quickly. So why doesn't the gene die out? If you only have one, then you have improved resistance to malaria.
