Cytogenetic evidence for asexual evolution of bdelloid rotifers.

Sexual Species Are Separated by Larger Genetic Gaps than Asexual Species in Rotifers

Why organisms diversify into discrete species instead of showing a continuum of genotypic and phenotypic forms is an important yet rarely studied question in speciation biology. Does species discreteness come from adaptation to fill discrete niches or from interspecific gaps generated by reproductive isolation? We investigate the importance of reproductive isolation by comparing genetic discret...

Independently Evolving Species in Asexual Bdelloid Rotifers

Asexuals are an important test case for theories of why species exist. If asexual clades displayed the same pattern of discrete variation as sexual clades, this would challenge the traditional view that sex is necessary for diversification into species. However, critical evidence has been lacking: all putative examples have involved organisms with recent or ongoing histories of recombination an...

Evidence for “ inter - and intraspecific horizontal genetic transfers ” between anciently asexual 1 bdelloid rotifers is explained by cross - contamination 2 3

Evolution: The End of an Ancient Asexual Scandal

Bdelloid rotifers were believed to have persisted and diversified in the absence of sex. Two papers now show they exchange genes with each other, via horizontal gene transfers as known in bacteria and/or via other forms of non-canonical sex.

Spatial and temporal escape from fungal parasitism in natural communities of anciently asexual bdelloid rotifers.

Sexual reproduction is costly, but it is nearly ubiquitous among plants and animals, whereas obligately asexual taxa are rare and almost always short-lived. The Red Queen hypothesis proposes that sex overcomes its costs by enabling organisms to keep pace with coevolving parasites and pathogens. If so, the few cases of stable long-term asexuality ought to be found in groups whose coevolutionary ...