Appendix B 377
1. Operational Taxonomic Unit [OTU]
Definition: Taxonomic units of different categorical ranks to be grouped into
more inclusive aggregates during classification (Sneath and Sokal). In
microbiology, a phylotype is an environmental DNA sequence or group of
sequences sharing more than an arbitrarily chosen level of similarity of a
particular gene marker (Moreira and López-García 2011).
Principal Authors: Sneath and Sokal 1973, Sokal and Sneath 1963.
Related Concepts: Microbial species, bacterial species, phenospecies, taxo-
nomic species, phylotype.^62. Least Inclusive Taxonomic Unit [LITU]
A phylospecies conception.
Definition: A taxonomic group that is diagnosable in terms of its autapomor-
phies, but has no fixed rank or binomial.
Principal Authors: Pleijel 1999, Pleijel and Rouse 2000, 2003.3. Metapopulation
Definition: A population of populations that go extinct locally and recolonize
(Levins 1970). A set of local populations of a single species that are linked
by dispersal (Hanski and Gilpin 1991).
Principal Authors: Hanski and Gilpin 1991, Levins 1970.
Related Concepts: Ecospecies, Mendelian populations.4. Smallest Named and Registered Clade [SNaRC]
A phylospecies concept.
Definition: The smallest named and registered clade [in the Phylocode
database].
Principal Authors: Mishler and Wilkins (2018).
Related Concept: Least inclusive taxonomic units.Bibliography
Aguilar, Javier Fuertes et al. 1999. Molecular evidence for the compilospecies model of
reticulate evolution in Armeria (Plumbaginaceae). Systematic Biology 48 (4):735 –754.
Atran, Scott. 1990. The Cognitive Foundations of Natural History. New York: Cambridge
University Press.
Avise, John C., and R. Martin Ball Jr. 1990. Principles of genealogical concordance in species
concepts and biological taxonomy. In Oxford Surveys in Evolutionary Biology, edited
by Douglas J. Futuyma and Janis Antonovics, 45–67. Oxford: Oxford University Press.
(^6) C. W. Cotterman in unpublished notes dated 1960, Denniston 1974.