title: Opinion: Re-evaluating prokaryotic species.
abstract: There is no widely accepted concept of species for prokaryotes, and assignment of isolates to species is based on measures of phenotypic or genome similarity. The current methods for defining prokaryotic species are inadequate and incapable of keeping pace with the levels of diversity that are being uncovered in nature. Prokaryotic taxonomy is being influenced by advances in microbial population genetics, ecology and genomics, and by the ease with which sequence data can be obtained. Here, we review the classical approaches to prokaryotic species definition and discuss the current and future impact of multilocus nucleotide-sequence-based approaches to prokaryotic systematics. We also consider the potential, and difficulties, of assigning species status to biologically or ecologically meaningful sequence clusters.
authors.affiliation: Laboratory of Microbiology and the Bioinformatics and Evolutionary Genomics Research Group, Ghent University/VIB, Ghent, Belgium. dirk.gevers@UGent.be
authors.forename: Dirk
authors.initials: D
authors.lastname: Gevers
authors.forename: Frederick M
authors.initials: FM
authors.lastname: Cohan
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Lawrence
authors.forename: Brian G
authors.initials: BG
authors.lastname: Spratt
authors.forename: Tom
authors.initials: T
authors.lastname: Coenye
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Feil
authors.forename: Erko
authors.initials: E
authors.lastname: Stackebrandt
authors.forename: Yves
authors.initials: Y
authors.lastname: Van de Peer
authors.forename: Peter
authors.initials: P
authors.lastname: Vandamme
authors.forename: Fabiano L
authors.initials: FL
authors.lastname: Thompson
authors.forename: Jean
authors.initials: J
authors.lastname: Swings
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D008957:Models, Genetic; D010802:Phylogeny
chemical_list: D004269:DNA, Bacterial