Editing Directional selection (section)

==Ecological impact==
Directional selection can quickly lead to vast changes in allele frequencies in a population because of the cumulative nature of reproduction of the fittest. Because the main cause for directional selection is different and changing environmental pressures, rapidly changing environments, such as those affected by [[climate change]], can cause drastic changes within populations.

=== Diversity ===
Limiting the number of genotypes in a certain population can be deleterious to the ecosystem as a whole by shrink the potential genetic [[gene pool]].<ref>{{Cite journal |last1=Star |first1=Bastiaan |last2=Spencer |first2=Hamish G. |date=May 2013 |title=Effects of Genetic Drift and Gene Flow on the Selective Maintenance of Genetic Variation |journal=Genetics |volume=194 |issue=1 |pages=235–244 |doi=10.1534/genetics.113.149781 |pmid=23457235 |pmc=3632471 }}</ref> Low amount of genetic variation can lead to [[Extinction event|mass extinctions]] and [[endangered species]] because of the large impact one mutation can have on the entire population if there are only a few specific genes present throughout.

=== Urban Influence ===
It is important to note the impact that humans have on genetic diversity as well, and be aware of the ways to reduce harmful impacts on natural environments.<ref>{{Cite journal |last=Mysterud |first=Atle |date=13 May 2011 |title=Selective harvesting of large mammals: how often does it result in directional selection? |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2011.02006.x |journal=Journal of Applied Ecology |language=en |volume=48 |issue=4 |pages=827–834 |doi=10.1111/j.1365-2664.2011.02006.x|url-access=subscription }}</ref> Major roads, waterway pollution, and [[urbanization]] all cause environmental selection and could potentially result in changes in allele frequencies.<ref>{{Cite journal |last=Hunter |first=Philip |date=April 2007 |title=The human impact on biological diversity |journal=EMBO Reports |volume=8 |issue=4 |pages=316–318 |doi=10.1038/sj.embor.7400951 |pmid=17401404 |pmc=1852758 }}</ref> Hunting may also play a role in directional selection, albeit more so in smaller populations.