nonecological speciation

{{Short description|Speciation not driven by divergent natural selection}}

File:Ecological vs Non-Ecological Speciation.svg or a unique environment whereas compatibility in reproduction involves mate-recognition morphology, communication systems, or other behaviors. Ecological speciation necessitates changes in both whereas non-ecological speciation only changes compatibility in reproduction.]]

When speciation is not driven by (or strongly correlated with) divergent natural selection, it can be said to be nonecological,{{Cite journal|last1=Rundell|first1=Rebecca J.|last2=Price|first2=Trevor D.|date=2009-07-01|title=Adaptive radiation, nonadaptive radiation, ecological speciation and nonecological speciation|url=https://www.cell.com/trends/ecology-evolution/abstract/S0169-5347(09)00126-8|journal=Trends in Ecology & Evolution|language=en|volume=24|issue=7|pages=394–399|doi=10.1016/j.tree.2009.02.007|issn=0169-5347|pmid=19409647|bibcode=2009TEcoE..24..394R }}{{Cite journal|last1=Czekanski-Moir|first1=Jesse E.|last2=Rundell|first2=Rebecca J.|date=2019-05-01|title=The Ecology of Nonecological Speciation and Nonadaptive Radiations|url=https://www.jessecm.org/s/czekanskimoirRundell2019_ecoNonAdRad.pdf|journal=Trends in Ecology & Evolution|language=en|volume=34|issue=5|pages=400–415|doi=10.1016/j.tree.2019.01.012|issn=0169-5347|pmid=30824193|bibcode=2019TEcoE..34..400C |s2cid=73494468 }} so as to distinguish it from the typical definition of ecological speciation: "It is useful to consider ecological speciation as its own form of species formation because it focuses on an explicit mechanism of speciation: namely divergent natural selection. There are numerous ways other than via divergent natural selection in which populations might become genetically differentiated and reproductively isolated."{{Cite book|last=Nosil, Patrik.|url=https://www.worldcat.org/oclc/787851773|title=Ecological speciation|date=2012|publisher=Oxford University Press|isbn=978-0-19-162801-6|location=Oxford|oclc=787851773}} It is likely that many instances of nonecological speciation are allopatric, especially when the organisms in question are poor dispersers (e.g., land snails, salamanders), however sympatric nonecological speciation may also be possible, especially when accompanied by an "instant" (at least in evolutionary time) loss of reproductive compatibility, as when polyploidization happens.{{Cite journal|last1=Les|first1=Donald H.|last2=Peredo|first2=Elena L.|last3=King|first3=Ursula M.|last4=Benoit|first4=Lori K.|last5=Tippery|first5=Nicholas P.|last6=Ball|first6=Cassandra J.|last7=Shannon|first7=Robynn K.|date=2015-01-01|title=Through thick and thin: Cryptic sympatric speciation in the submersed genus Najas (Hydrocharitaceae)|url=http://www.sciencedirect.com/science/article/pii/S105579031400342X|journal=Molecular Phylogenetics and Evolution|language=en|volume=82|pages=15–30|doi=10.1016/j.ympev.2014.09.022|pmid=25300454|bibcode=2015MolPE..82...15L |issn=1055-7903}} Other potential mechanisms for nonecological speciation include mutation-order speciation{{Cite journal|last1=Nosil|first1=Patrik|last2=Flaxman|first2=Samuel M.|date=2011-02-07|title=Conditions for mutation-order speciation|url= |journal=Proceedings of the Royal Society B: Biological Sciences|volume=278|issue=1704|pages=399–407|doi=10.1098/rspb.2010.1215|pmc=3013408|pmid=20702458}} and changes in chirality in gastropods.{{Cite journal|last1=Gittenberger|first1=Edmund|last2=Hamann|first2=Thomas D.|last3=Asami|first3=Takahiro|date=2012-04-20|title=Chiral Speciation in Terrestrial Pulmonate Snails|journal=PLOS ONE|language=en|volume=7|issue=4|pages=e34005|doi=10.1371/journal.pone.0034005|issn=1932-6203|pmc=3332057|pmid=22532825|bibcode=2012PLoSO...734005G|doi-access=free}}

Nonecological speciation might not be accompanied by strong morphological differentiation, so might give rise to cryptic species, however there are some species that are difficult for humans to differentiate that are strongly differentiated with respect to their resource use, and so are likely a result of ecological speciation (e.g., host shifts in parasites or phytophagous insects).{{Cite journal|last1=Faucci|first1=Anuschka|last2=Toonen|first2=Robert J|last3=Hadfield|first3=Michael G|date=2007-01-07|title=Host shift and speciation in a coral-feeding nudibranch|url= |journal=Proceedings of the Royal Society B: Biological Sciences|volume=274|issue=1606|pages=111–119|doi=10.1098/rspb.2006.3685|pmc=1679885|pmid=17134995}}{{Cite journal|last1=Lee|first1=Y.|last2=Lee|first2=W.|last3=Lee|first3=S.|last4=Kim|first4=H.|date=February 2015|title=A cryptic species of Aphis gossypii (Hemiptera: Aphididae) complex revealed by genetic divergence and different host plant association|url=https://www.cambridge.org/core/journals/bulletin-of-entomological-research/article/cryptic-species-of-aphis-gossypii-hemiptera-aphididae-complex-revealed-by-genetic-divergence-and-different-host-plant-association/231E07EACE5DE65CAA8CADA3CE4BCD96|journal=Bulletin of Entomological Research|language=en|volume=105|issue=1|pages=40–51|doi=10.1017/S0007485314000704|pmid=25413997|s2cid=26358620|issn=0007-4853}} When species recognition/sexual selection plays a strong role in maintaining species boundaries, the species generated by nonecological speciation might be straightforward for humans to differentiate, as in some odonates.{{Cite journal |last1=Wellenreuther |first1=Maren |author-link=Maren Wellenreuther |last2=Sánchez-Guillén |first2=Rosa Ana |date=2016 |title=Nonadaptive radiation in damselflies |url= |journal=Evolutionary Applications |language=en |volume=9 |issue=1 |pages=103–118 |bibcode=2016EvApp...9..103W |doi=10.1111/eva.12269 |issn=1752-4571 |pmc=4780385 |pmid=27087842}}