Editing Stabilizing selection (section)

== Analyzing stabilizing selection ==
There are four primary types of data used to quantify stabilizing selection in a population. The first type of data is an estimation of fitness of different phenotypes within a single generation. Quantifying fitness in a single generation creates predictions for the expected fate of selection. The second type of data is changes in allelic frequencies or phenotypes across different generations. This allows quantification of change in prevalence of a certain phenotype, indicating the type of selection. The third type of data is differences in allelic frequencies across space. This compares selection occurring in different populations and environmental conditions. The fourth type of data is DNA sequences from the genes contributing to observes phenotypic differences. The combination of these four types of data allow population studies that can identify the type of selection occurring and quantify the extent of selection.<ref>{{cite journal | vauthors = Linnen CR, Hoekstra HE | title = Measuring natural selection on genotypes and phenotypes in the wild | journal = Cold Spring Harbor Symposia on Quantitative Biology | volume = 74 | pages = 155–68 | date = 2009 | pmid = 20413707 | pmc = 3918505 | doi = 10.1101/sqb.2009.74.045 }}</ref>

However, a meta-analysis of studies that measured selection in the wild failed to find an overall trend for stabilizing selection.<ref>{{cite journal | vauthors = Kingsolver JG, Hoekstra HE, Hoekstra J, Berrigan D, Vignieri SN, Hill CE, Hoang A, Gilbert P, Beerli P | year = 2001 | title = The Strength of Super Genetic Selection in Natural Populations | journal = The American Naturalist | volume = 157 | issue = 3 | pages = 245–61 | url = http://www.oeb.harvard.edu/faculty/hoekstra/pdfs/kingsolver2001amnat.pdf | doi = 10.1086/319193 | pmid = 18707288 | s2cid = 11408433 }}</ref> The reason can be that methods for detecting stabilizing selection are complex. They can involve studying the changes that causes natural selection in the mean and variance of the trait, or measuring fitness for a range of different [[phenotype]]s under natural conditions and examining the relationship between these fitness measurements and the trait value, but analysis and interpretation of the results is not straightforward.<ref name="pmid28556011">{{cite journal | vauthors = Lande R, Arnold SJ | title = The Measurement of Selection on Correlated Characters | journal = Evolution; International Journal of Organic Evolution | volume = 37 | issue = 6 | pages = 1210–1226 | date = November 1983 | pmid = 28556011 | doi = 10.1111/j.1558-5646.1983.tb00236.x | s2cid = 36544045 | doi-access = free }}</ref>