Prokaryotic Intraspecies Diversity


Intraspecies prokaryotic diversity is a multifaceted research field with widespread connections to other biological disciplines. The dynamics of intraspecies diversity can be understood within models of bacterial microevolution, as population genetics is the basic theoretic foundation for explaining the mechanisms of evolution and speciation. Also, it directly relates to functional molecular biology, physiology and metabolism. Last, but not least, intraspecies diversity is inseparably linked to systematics and taxonomy, and to the current discussions on the prokaryotic species concept.

Key concepts

The field of prokaryotic intraspecies diversity is inseparably linked to the issue of species concepts. Currently, there is a strong debate as to whether further apply the historically evolved and pragmatic but in several aspects dissatisfying operational‐based species definition, or to develop theory‐based species concepts leading to new definitions. Any theory‐based species concepts that might be implemented must respect the current set of rules of naming species, the Bacteriological Code, to avoid substantial confusion.

Although this may seem on the first spot trivial and self‐evident, it must become clear that strains within a so‐called species can be fundamentally different from each other. The theoretical foundation for understanding such intraspecies diversity is the field of population genetics, which is based on analytical mathematics. Intraspecies diversity can be analysed using three principal approaches (i) theoretical studies including computer simulation, (ii) Experimental Evolution and (iii) the study of natural populations. Ideally, these approaches should be combined. Each of these principal approaches should be based on three equivalent pillars (i) genetic markers, (ii) phenotypic traits and (iii) a solid knowledge on the habitat in which the bacterial strains most probably evolved.

Keywords: population genetics; microevolution; theory‐based species concepts; prokaryote taxonomy; prokaryote nomenclature

Figure 1.

This figure summarizes the interrelationship of intraspecies diversity to other biological disciplines.



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Sikorski, Johannes(Mar 2009) Prokaryotic Intraspecies Diversity. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0020377]