Prokaryotic species are sui generis evolutionary units

Show simple item record Palmer, Marike Venter, S.N. (Stephanus Nicolaas) Coetzee, Martin Petrus Albertus Steenkamp, Emma Theodora 2019-08-01T12:25:17Z 2019-03
dc.description.abstract Many gene flow barriers associated with genetic isolation during eukaryotic species divergence, are lacking in prokaryotes. In these organisms the processes associated with horizontal gene transfer (HGT) may provide both the homogenizing force needed for genetic cohesion and the genetic variation essential to speciation. This is because HGT events can broadly be grouped into genetic conversions (where endogenous genetic material are replaced with homologs acquired from external sources) and genetic introductions (where novel genetic material is acquired from external sources). HGT-based genetic conversions therefore causes homogenization, while genetic introductions drive divergence of populations upon fixation of genetic variants. The impact of HGT in different prokaryotic species may vary substantially and can range from very low levels to rampant HGT, producing chimeric groups of isolates. Combined with other evolutionary processes, these varying levels of HGT causes diversity space to be occupied by unique groups that are mostly incomparable in terms of genetic similarity, genomic cohesion and evolutionary age. As a result, the conventional, cut-off based metrics for species delineation are not adequate. Rather, a pluralistic approach to prokaryotic species recognition is required to accommodate the unique evolutionary ages and tendencies, population dynamics, and evolutionary fates of individual prokaryotic species. Following this approach, all prokaryotic species may be regarded as unique and each of their own kind (sui generis). Taxonomic decisions thus require evolutionary information that integrates vertical inheritances with all possible sources of genetic heterogeneity to ultimately produce robust and biologically meaningful classifications. en_ZA
dc.description.department Biochemistry en_ZA
dc.description.department Forestry and Agricultural Biotechnology Institute (FABI) en_ZA
dc.description.department Genetics en_ZA
dc.description.department Microbiology and Plant Pathology en_ZA
dc.description.embargo 2020-03-01
dc.description.librarian hj2019 en_ZA
dc.description.uri en_ZA
dc.identifier.citation Palmer, M., Venter, S.N., Coetzee, M.P.A. et al. 2019, 'Prokaryotic species are sui generis evolutionary units', Systematic and Applied Microbiology, vol. 42, no. 2, pp. 145-158. en_ZA
dc.identifier.issn 0723-2020
dc.identifier.other 10.1016/j.syapm.2018.10.002
dc.language.iso en en_ZA
dc.publisher Elsevier en_ZA
dc.rights © 2018 Elsevier GmbH. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Systematic and Applied Microbiology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Systematic and Applied Microbiology, vol. 42, no. 2, pp. 145-158, 2019. doi : 10.1016/j.syapm.2018.10.002. en_ZA
dc.subject Horizontal gene transfer (HGT) en_ZA
dc.subject Archaea en_ZA
dc.subject Bacteria en_ZA
dc.subject Evolution en_ZA
dc.subject Speciation en_ZA
dc.title Prokaryotic species are sui generis evolutionary units en_ZA
dc.type Postprint Article en_ZA

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