Prokaryotic Systematics: Theoretical Overview in the Light of Molecular Advances


Systematics describes the ordering of information on organisms and plays an important role in communicating information within biological sciences. Systematics seeks to reveal the phenotypic and genotypic diversity of organisms while relating this information to natural interactions and evolutionary history. Systematics may utilise a wide range of data and is not limited to the experimental methods that it may draw on in order to make sensible comparisons between organisms. Systematics requires an underlying order, and both systematics and taxonomy are strongly dependent on theory and philosophy, which are used to create this order. Systematics is a complex area, which has seen much change and progress in the last century. Developments in molecular biology have been adapted in line with the theory and philosophy and have become established in systematics. In the molecular era, accumulated data including those genomics‐derived will be the driving force behind the revalidation of currently used theories and hypotheses formulated in systematics and lead towards the establishment of a ‘genomic taxonomy’.

Key Concepts:

  • Systematics seeks to discover phenotypic and genotypic diversity of organisms.

  • Taxonomy, the theory and practice of identifying, describing, naming and classifying organisms.

  • Current systematists make extensive use of molecular biology and bioinformatics to study microorganisms.

  • The basis of molecular phylogeny refers to evolutive relationship of microorganisms that can be inferred from the relationships of their genes and their genomes.

  • Genomics explores the biology of organisms through their genetic blueprints.

  • Metagenomics provide access to genome for prediction of the ecological role of members of microbial communities.

  • Current comparative genomics approaches will lead towards establishment of a ‘genomic taxonomy’.

Keywords: prokaryotes; evolution; systematics; taxonomy; genomics; phylogenomics; biogeography

Figure 1.

An unrooted maximum likelihood bacterial genome tree. The tree was constructed from concatenated protein sequence alignments derived from 31 housekeeping genes by Wu and Eisen (© 2008 Wu and Eisen; licensee BioMed Central Ltd.). All major phyla are separated into their monophyletic groups and are highlighted in colour. The branches with bootstrap support of more than 80 (out of 100 replicates) are indicated by black dots. Reproduced from Wu and Eisen (). © BioMed Central Ltd – Open Access.



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Kurtböke, Ipek(Apr 2014) Prokaryotic Systematics: Theoretical Overview in the Light of Molecular Advances. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0000448.pub2]