Evolution and Sex
In the context of sex maintenance, asexual reproduction has two main disadvantages:
1. The accumulation of deleterious mutations.
- The deleterious mutation hypothesis proposes that sex exists to purge damaging genetic mutations from a species3.
- The chosen method to model this purging (models range from deterministic to stochastic4) largely determines if the hypothesis holds true.
- The mutation rate must be high enough so that a clone's genetic costs outweigh its productivity for the deleterious mutation hypothesis to hold true. The cost of sexual reproduction can easily exceed the benefits5.
2. Asexual organisms are homozygous.
- All members of an asexual population will have the same defensive alleles against parasites.