Mutational meltdown

Mutational meltdown (not to be confused with the concept of an error catastrophe) is the accumulation of harmful mutations in a small population, which leads to loss of fitness and decline of the population size, which may lead to further accumulation of deleterious mutations due to fixation by genetic drift. Mutational meltdown (not to be confused with the concept of an error catastrophe) is the accumulation of harmful mutations in a small population, which leads to loss of fitness and decline of the population size, which may lead to further accumulation of deleterious mutations due to fixation by genetic drift. A population experiencing mutational meltdown is trapped in a downward spiral and will go extinct if the phenomenon lasts for some time. Usually, the deleterious mutations would simply be selected away, but during mutational meltdown, the number of individuals thus suffering an early death is too large relative to overall population size so that mortality exceeds the birth rate.