Editing Allee effect (section)

=== Human induced ===
Classic economic theory predicts that human exploitation of a population is unlikely to result in species extinction because the escalating costs to find the last few individuals will exceed the fixed price one achieves by selling the individuals on the market. However, when rare species are more desirable than common species, prices for rare species can exceed high harvest costs. This phenomenon can create an "anthropogenic" Allee effect where rare species go extinct but common species are sustainably harvested.<ref name=":0">{{Cite journal|last1=Courchamp|first1=Franck|last2=Angulo|first2=Elena|last3=Rivalan|first3=Philippe|last4=Hall|first4=Richard J.|last5=Signoret|first5=Laetitia|last6=Bull|first6=Leigh|last7=Meinard|first7=Yves|date=2006-11-28|title=Rarity Value and Species Extinction: The Anthropogenic Allee Effect|journal=PLOS Biology|volume=4|issue=12|pages=e415|doi=10.1371/journal.pbio.0040415|pmid=17132047|issn=1545-7885|pmc=1661683 |doi-access=free }}</ref> The anthropogenic Allee effect has become a standard approach for conceptualizing the threat of economic markets on endangered species.<ref name=":1">{{Cite journal|last1=Holden|first1=Matthew H.|last2=McDonald-Madden|first2=Eve|date=2017-09-21|title=High prices for rare species can drive large populations extinct: the anthropogenic Allee effect revisited|journal=Journal of Theoretical Biology|volume=429|pages=170–180|doi=10.1016/j.jtbi.2017.06.019|pmid=28669883|arxiv=1703.06736|bibcode=2017JThBi.429..170H|s2cid=4877874}}</ref> However, the original theory was posited using a one dimensional analysis of a two dimensional model.<ref name=":0" /><ref name=":1" />  It turns out that a two dimensional analysis yields an Allee curve in human exploiter and biological population space and that this curve separating species destined to extinction vs persistence can be complicated. Even very high population sizes can potentially pass through the originally proposed Allee thresholds on predestined paths to extinction.<ref name=":1" />