title: Using population genetic theory and DNA sequences for species detection and identification in asexual organisms.
abstract: BACKGROUND
  It is widely agreed that species are fundamental units of biology, but there is little agreement on a definition of species or on an operational criterion for delimiting species that is applicable to all organisms.
  
  
  RESULTS
  We focus on asexual eukaryotes as the simplest case for investigating species and speciation. We describe a model of speciation in asexual organisms based on basic principles of population and evolutionary genetics. The resulting species are independently evolving populations as described by the evolutionary species concept or the general lineage species concept. Based on this model, we describe a procedure for using gene sequences from small samples of individuals to assign them to the same or different species. Using this method of species delimitation, we demonstrate the existence of species as independent evolutionary units in seven groups of invertebrates, fungi, and protists that reproduce asexually most or all of the time.
  
  
  CONCLUSIONS
  This wide evolutionary sampling establishes the general existence of species and speciation in asexual organisms. The method is well suited for measuring species diversity when phenotypic data are insufficient to distinguish species, or are not available, as in DNA barcoding and environmental sequencing. We argue that it is also widely applicable to sexual organisms.
authors.affiliation: Department of Ecology and Evolutionary Biology, Biological Sciences West, The University of Arizona, Tucson, Arizona, United States of America. birky@u.arizona.edu
authors.forename: C William
authors.initials: CW
authors.lastname: Birky
authors.forename: Joshua
authors.initials: J
authors.lastname: Adams
authors.forename: Marlea
authors.initials: M
authors.lastname: Gemmel
authors.forename: Julia
authors.initials: J
authors.lastname: Perry
mesh_terms: D000818:Animals; D001483:Base Sequence; D000460:Chlorophyta / Q000235:genetics; D005658:Fungi / Q000235:genetics; D049810:Genetic Speciation; D005828:Genetics, Population; D052836:Heterotrophic Processes / Q000235:genetics; D008925:Mites / Q000235:genetics; D009835:Oligochaeta / Q000235:genetics; D010802:Phylogeny; D011157:Population Dynamics; D012100:Reproduction, Asexual / Q000235:genetics*; D012403:Rotifera / Q000235:genetics; D013045:Species Specificity