Rotaria is a genus of asexual, microscopic animal known as a

bdelloid rotifer Bdelloidea (Greek ''βδέλλα'', ''bdella'', "leech") is a class of rotifers found in freshwater habitats all over the world. There are over 450 described species of bdelloid rotifers (or 'bdelloids'), distinguished from each other mainl ...

. Analysis published in 2007 of morphology and DNA sequence data of species form the genus confirmed that despite their asexual mechanism of

reproduction Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...

, two fundamental properties of

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, independent evolution and ecological divergence by

natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Charle ...

occurred. This demonstrates that sex is not a necessary condition for speciation.Independently Evolving Species in Asexual Bdelloid Rotifers
Fontaneto D, Herniou EA, Boschetti C, Caprioli M, Melone G, et al. PLoS Biology Vol. 5, No. 4, e87

References

{{Taxonbar, from=Q2168039 Bdelloidea Rotifer genera