Hobbies And Interests
Mate Finding
Asexual reproduction does away with the need to find and court with a mate. This is especially useful for animals which have low mobility and population density, as locating a mate would represent a significant cost in terms of energy and time. Asexual reproduction allows animals to reproduce whenever conditions are right, assuring them of the chance of passing on their genes.
Prevalance of Mother's Genes In the Population
In evolutionary biology, the gene rather than the species, group or individual is usually understood as the unit of natural selection. This means that individual genes, in cooperation or competition with other genes, are selected by evolution if they manage, via the plant or animal which carries them, to reproduce themselves successfully, regardless of the consequences for the individual animal which carries them. From this perspective it can be said that asexual reproduction is an advantage to an asexually reproducing animal, meaning the collection of genes it carries, because its offspring carries only its genes, rather than carrying half its genes and half from the father. This means the genes of the mother do not have to "share" space in the genome of the offspring and so all the energy and resources of the offspring go exclusively into carrying and reproducing its genes instead of being divided between the mother's and father's. For the genes within a particular asexual female, this is very useful as it will increase their prevalence within the population. However, the majority of the genes carried by the male and female of a species are the same, with only a few variations between individuals. Perhaps then it would be more accurate to say that asexual reproduction is a benefit to those particular genes that the mother carries, which might be substituted for other genes, should the animal reproduce sexually.
No Loss of Beneficial Mutations
In sexual reproduction, the genes of the mother and father are to some extent randomly shuffled together. If a good combination appears, this animal has a better chance of reproducing and so will pass on this mixture of genes, but this successful combination will once again be shuffled together with those of the sexual partner. The more successful the combination is, the more individuals will end up carrying that combination. This will increase the chances of sexual partners having similar combinations of genes, making the offspring more similar to both parents. However, until a particular gene or combination of genes is found in the majority of the species, then no matter how useful that gene or combination is, there is a good chance that the offspring will not receive it. This means that beneficial mutations and adaptations take can take a relatively long time to spread through a population.
In asexual reproduction, when a beneficial mutation appears it does not risk having its place taken in the offspring by other genes from the father. This means that beneficial mutations can quickly spread through an asexually reproducing population, allowing them to quickly take advantage of a biological niche.
The Meselson Effect
Bdelloid rotifers are an asexual species of microscopic marine animal. Their asexual reproduction has allowed them to develop what is essentially a pair of different genomes, both within the same body. This is known as the Meselson effect after the scientist who discovered it. This phenomenon generates a certain amount of genetic diversity within the same individual. There is evidence to suggest that this helps the bdelloid rotifers to survive dehydration as the two genomes are capable of producing complimentary proteins which protect it from the effects of desiccation.