Editing Sympatric speciation (section)

{{Short description|Evolution of a new species from an ancestor in the same location}}
[[File:Sympatric Speciation Schematic.svg|thumb|upright=1.8|In sympatric speciation, reproductive isolation evolves within a population without the aid of geographic barriers.]]
{{Evolutionary biology}}

'''Sympatric speciation''' is the [[evolution]] of a new species from a surviving [[Common descent|ancestral species]] while both continue to inhabit the same geographic region. In evolutionary biology and [[biogeography]], ''sympatric'' and ''[[sympatry]]'' are terms referring to organisms whose [[Range (biology)|ranges]] overlap so that they occur together at least in some places. If these organisms are closely related (e.g. [[sister species]]), such a distribution may be the result of sympatric [[speciation]]. [[Etymological]]ly, sympatry is derived {{ety|el|''[[wikt:συν-|συν]]'' (sun-)|together||''[[wikt:πατρίς|πατρίς]]'' (patrís)|fatherland}}.<ref name=Poulton1903/> The term was coined by [[Edward Bagnall Poulton]] in 1904, who explains the derivation.<ref name=Poulton1903>{{cite journal | last1 = Poulton | first1 = E. B. | author-link = Edward Bagnall Poulton | year = 1904 | title = What is a species? | journal = Proceedings of the Entomological Society of London | volume = 1903 | pages = 77–116 }}</ref>

Sympatric speciation is one of three traditional geographic modes of speciation.<ref name="Futuyma 2001">Futuyma, D. J. 2001. ''Evolution'' (2nd edition). Sinauer Associates, Inc.{{page needed|date=November 2013}}</ref><ref name="Fitzpatrick et al. 2008">{{cite journal |doi=10.1111/j.1420-9101.2008.01611.x |title=What, if anything, is sympatric speciation? |year=2008 |last1=Fitzpatrick |first1=B. M. |last2=Fordyce |first2=J. A. |last3=Gavrilets |first3=S. |journal=Journal of Evolutionary Biology |volume=21 |issue=6 |pages=1452–9 |pmid=18823452|s2cid=8721116 |doi-access=free }}</ref> [[Allopatric speciation]] is the evolution of species caused by the geographic isolation of two or more populations of a species. In this case, divergence is facilitated by the absence of gene flow. [[Parapatric speciation]] is the evolution of geographically adjacent populations into distinct species. In this case, divergence occurs despite limited interbreeding where the two diverging groups come into contact. In sympatric speciation, there is no geographic constraint to interbreeding. These categories are special cases of a continuum from zero (sympatric) to complete (allopatric) spatial segregation of diverging groups.<ref name="Fitzpatrick et al. 2008" />

In multicellular [[Eukaryotes|eukaryotic]] organisms, sympatric speciation is a plausible process that is known to occur, but the frequency with which it occurs is not known.<ref name="Bolnick and Fitzpatrick 2007">{{cite journal |doi=10.1146/annurev.ecolsys.38.091206.095804 |title=Sympatric Speciation: Models and Empirical Evidence |year=2007 |last1=Bolnick |first1=Daniel I. |last2=Fitzpatrick |first2=Benjamin M. |journal=Annual Review of Ecology, Evolution, and Systematics |volume=38 |pages=459–87}}</ref>
In bacteria, however, the analogous process (defined as "the origin of new bacterial species that occupy definable [[ecological niche]]s") might be more common because bacteria are less constrained by the homogenizing effects of sexual reproduction and are prone to comparatively dramatic and rapid genetic change through [[horizontal gene transfer]].<ref name="King, Stansfield, Mulligan">{{cite book | last =King, Stansfield, Mulligan | title =Dictionary of Genetics | publisher =Oxford University Press| edition = 7th | year =2006 }}{{page needed|date=November 2013}}</ref>