Editing Competition (section)

== Biology and ecology ==
<!-- This section is linked from [[Natural selection]] -->
{{Main|Competition (biology)}}
Competition within, between, and among species is one of the most important forces in biology, especially in the field of [[ecology]].<ref name="Keddy, P.A 2001">{{Cite book |last=Keddy |first=Paul A. |url=https://www.worldcat.org/oclc/840307667 |title=Competition |date=2001 |publisher=Springer Netherlands |isbn=978-94-010-0694-1 |edition=2nd |location=Dordrecht |oclc=840307667}}</ref>

Competition between members of a species ("intraspecific") for resources such as [[food]], [[water]], [[Territory (animal)|territory]], and [[sunlight]] may result in an increase in the frequency of a variant of the species best suited for survival and reproduction until its fixation within a population. However, competition among resources also has a strong tendency for diversification between members of the same species, resulting in coexistence of competitive and non-competitive strategies or cycles between low and high competitiveness. Third parties within a species often favour highly competitive strategies leading to species extinction when environmental conditions are harsh ([[evolutionary suicide]]).<ref>{{cite journal|last1=Baldauf|first1=Sebastian A.|last2=Engqvist|first2=Leif|last3=Weissing|first3=Franz J.|title=Diversifying evolution of competitiveness|journal=Nature Communications|date=29 October 2014|volume=5|pages=5233|doi=10.1038/ncomms6233|pmid=25351604|bibcode=2014NatCo...5.5233B|doi-access=free}}</ref>

Competition is also present between species ("interspecific"). When resources are limited, several species may depend on these resources. Thus, each of the species competes with the others to gain access to the resources. As a result, species less suited to compete for the resources may [[extinction|die out]] unless they [[adaptation|adapt]] by character dislocation, for instance. According to [[evolutionary theory]], this competition within and between species for resources plays a significant role in [[natural selection]]. At shorter time scales, competition is also one of the most important factors controlling diversity in ecological communities, but at larger scales expansion and contraction of ecological space is a much larger factor than competition.<ref name="SahneyBentonFerry2010">{{cite journal|author1=Sahney, S. |author2=Benton, M.J. |author3=Ferry, P.A.|year=2010|title=Links between global taxonomic diversity, ecological diversity and the expansion of vertebrates on land|journal=Biology Letters|volume=6|issue=4|pages=544–47|doi=10.1098/rsbl.2009.1024|pmc=2936204|pmid=20106856}}</ref> This is illustrated by living plant communities where asymmetric competition and competitive dominance frequently occur.<ref name="Keddy, P.A 2001" /> Multiple examples of symmetric and asymmetric competition also exist for animals.<ref>{{cite journal|last1=Borzée|first1=Amaël|last2=Kim|first2=Jun Young|last3=Jang|first3=Yikweon|title=Asymmetric competition over calling sites in two closely related treefrog species|journal=Scientific Reports|date=7 Sep 2016|volume=6|page=32569|doi=10.1038/srep32569|pmc=5013533|pmid=27599461|bibcode=2016NatSR...632569B}}</ref>