naa a22 4500 510780350 CHVBK 20180411083245.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s11692-012-9219-y doi (NATIONALLICENCE)springer-10.1007/s11692-012-9219-y Lodé Thierry UMR-CNRS 6552 ETHOS, Université de Rennes 1, Campus de Beaulieu, Rennes, France aut Adaptive Significance and Long-Term Survival of Asexual Lineages [Elektronische Daten] [Thierry Lodé] Important questions remain about the long-term survival and adaptive significance of eukaryotic asexual lineages. Numerous papers dealing with sex advantages still continued to compare parthenogenetic populations versus sexual populations arguing that sex demonstrates a better fitness. Because asexual lineages do not possess any recombination mechanisms favoring rapid changes in the face of severe environmental conditions, they should be considered as an evolutionary dead-end. Nevertheless, reviewing literature dealing with asexual reproduction, it is possible to draw three stimulating conclusions. (1) Asexual reproduction in eukaryotes considerably differs from prokaryotes which experience recombination but neither meiosis nor syngamy. Recombination and meiosis would be a driving force for sexual reproduction. Eukaryotes should therefore be considered as a continuum of sexual organisms that are more or less capable (and sometimes incapable) of sexual reproduction. (2) Rather than revealing ancestral eukaryotic forms, most known lineages of asexual eukaryotes have lost sex due to a genomic conflict affecting their sexual capacity. Thus, it could be argued that hybridization is a major cause of their asexuality. Asexuality may have evolved as a reproductive mechanism reducing conflict within organisms. (3) It could be proposed that, rather than being generalists, parthenogenetic hybrid lineages could be favored when exploiting peculiar restricted ecological niches, following the "frozen niche variation” model. Although hybrid events may result in sex loss, probably caused by genomic conflict, asexual hybrids could display new original adaptive traits, and the rapid colonization of environments through clonal reproduction could favor their long-term survival, leading to evolutionary changes and hybrid speciation. Examination of the evolutionary history of asexual lineages reveals that evolutionary processes act through transitional stages in which even very small temporary benefits may be enough to counter the expected selective disadvantages. Springer Science+Business Media New York, 2012 Frozen niche variation nationallicence Hybrid nationallicence Parthenogenesis nationallicence Red Queen nationallicence Sexual conflict nationallicence Speciation nationallicence Evolutionary Biology Springer US; http://www.springer-ny.com 40/3(2013-09-01), 450-460 0071-3260 40:3<450 2013 40 11692 https://doi.org/10.1007/s11692-012-9219-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11692-012-9219-y text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Lodé Thierry UMR-CNRS 6552 ETHOS, Université de Rennes 1, Campus de Beaulieu, Rennes, France aut NATIONALLICENCE 773 0- Evolutionary Biology Springer US; http://www.springer-ny.com 40/3(2013-09-01), 450-460 0071-3260 40:3<450 2013 40 11692 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer