Muller's Ratchet

Muller's Ratchet

Muller's Ratchet started as a suggestion as to why sex developed.  It shows that through asexual reproduction the loss of a gene would mean that all following progeny would also no longer have that particular gene.  Though the introduction of sex and having recombination of genes, it is possible for a lost gene of on parent to be reintroduced into the offspring so long as the other parent has it.  This means that mutations that are detrimental to species that reproduce asexually might only affect a few individuals before the mutation is breed out of existence.