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A phylogenetic network is any graph used to visualize evolutionary relationships between sequences, genes, chromosomes, genomes, or species. It is employed when reticulate events such as hybridization, horizontal gene transfer, recombination, or gene duplication and loss are believed to be involved. They differ from Phylogenetic Trees by the explicit modeling, by means of the addition of hybrid nodes (nodes with two parents) instead of only tree nodes (nodes with only one parent).[1] Phylogenetic trees are a subset of phylogenetic networks. Phylogenetic networks can be inferred and visualised with software such as SplitsTree. A standard format for representing phylogenetic networks is the Newick format[2].
Many kinds and subclasses of phylogenetic networks have been defined based on the biological phenomenon they represent or which data they are built from (hybridization networks, usually built from rooted trees, recombination networks from binary sequences, median networks from a set of splits, optimal realizations and reticulograms from a distance matrix), or restrictions to get computationally tractable problems (galled trees, and their generalizations level-k phylogenetic networks, tree-child or tree-sibling phylogenetic networks).
[edit] Microevolution
Phylogenetic trees also have trouble depicting microevolutionary events, for example the geographical distribution of muskrat or fish populations of a given species among river networks, because there is no species boundary to prevent gene flow between populations. Therefore, a more general phylogenetic network better depicts these situations.[3]
[edit] References
- ^ "Characterization of Reticulate Networks Based on the Coalescent with Recombination". Mol Biol Evol 25 (12): 2517–2520. 2008 October 15. OCLC doi: 10.1093/molbev/msn219. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2582979.
- ^ "Extended Newick: it is time for a standard representation of phylogenetic networks". BMC Bioinformatics 9 (532). 2008 December 15. OCLC doi: 10.1186/1471-2105-9-532.. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=19077301.
- ^ Legendre, P; Makarenkov, V (Apr 2002), "Reconstruction of biogeographic and evolutionary networks using reticulograms", Systematic biology 51 (2): 199–216, doi:10.1080/10635150252899725, ISSN 1063-5157, PMID 12028728
- D. H. Huson and R. Rupp, Phylogenetic Networks, Cambridge University Press, in preparation.
[edit] See also
[edit] Software to compute phylogenetic networks
[edit] External links
- A tutorial that reviews the terminology used for phylogenetic networks and covers both split networks and reticulate networks, their definition and interpretation.
