Editing Directional selection (section)

===Sockeye salmon===
[[File:Sockeye salmon swimming right.jpg|thumb|Sockeye Salmon]]
[[Salmon|Sockeye salmon]] are one of the many species of fish that are [[anadromous]], in which individuals migrate to the same rivers in which they were born to reproduce. These migrations happen around the same time every year, but a 2007 study shows that sockeye salmon found in the waters of the [[Bristol Bay]] in [[Alaska]] have recently undergone directional selection on the timing of migration.<ref>{{Cite journal |last=Quinn |first=Thomas P. |date=April 2007 |title=Directional selection by fisheries and the timing of sockeye salmon (Oncorhynchus Nerka) Migrations |url=https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/06-0771 |journal=Ecological Applications|volume=17 |issue=3 |pages=731–739 |doi=10.1890/06-0771 |pmid=17494392 |bibcode=2007EcoAp..17..731Q |url-access=subscription }}</ref> In this study, two populations of sockeye salmon, [[Egegik River|Egegik]] and [[Ugashik River|Ugashik]], were observed. Data from 1969–2003 provided by the [[Alaska Department of Fish and Game]] were divided into five sets of seven years and plotted for average arrival to the fishery.  After analyzing the data, it was determined that in both populations the average migration date was earlier and the populations were undergoing directional selection as a result of changing ecological conditions. The Egegik population experienced stronger selection and the migration date shifted four days. The paper suggests that fisheries can be a factor driving this selection because fishing occurs more often in the later periods of migration (especially in the Egegik district), preventing those fish from reproducing.<ref>{{cite journal | last1=Quinn | first1=Thomas P. | last2=Hodgson | first2=Sayre | last3=Flynn | first3=Lucy | last4=Hilborn | first4=Ray | last5=Rogers | first5=Donald E. | title=Directional Selection by Fisheries and the Timing of Sockeye Salmon (Oncorhynchus Nerka) Migrations | journal=Ecological Applications | publisher=Wiley | volume=17 | issue=3 | year=2007 | issn=1051-0761 | doi=10.1890/06-0771 | pmid=17494392 | pages=731–739| bibcode=2007EcoAp..17..731Q }}</ref> This discovery also goes to show that in addition to environmental changes, human behaviors can also have massive effects on the selection of species around them.<ref name=":2">{{Cite journal |last=Lin |first=J. E. |last2=Hard |first2=J. J. |last3=Naish |first3=K. A. |last4=Peterson |first4=D. |last5=Hilborn |first5=R. |last6=Hauser |first6=L. |date=May 2016 |title=It’s a bear market: evolutionary and ecological effects of predation on two wild sockeye salmon populations |url=https://www.nature.com/articles/hdy20163 |journal=Heredity |language=en |volume=116 |issue=5 |pages=447–457 |doi=10.1038/hdy.2016.3 |issn=1365-2540|pmc=4834386 }}</ref>