Stabilizing selection

1: directional selection: a single extreme phenotype favoured.
2, stabilizing selection: intermediate favoured over extremes.
3: disruptive selection: extremes favoured over intermediate.
X-axis: phenotypic trait
Y-axis: number of organisms
Group A: original population
Group B: after selection

Stabilizing selection (not to be confused with negative or purifying selection[1][2]) is a type of natural selection in which the population mean stabilizes on a particular non-extreme trait value. This is thought to be the most common mechanism of action for natural selection because most traits do not appear to change drastically over time.[3] Stabilizing selection commonly uses negative selection (a.k.a. purifying selection) to select against extreme values of the character. Stabilizing selection is the opposite of disruptive selection. Instead of favoring individuals with extreme phenotypes, it favors the intermediate variants. Stabilizing selection tends to remove the more severe phenotypes, resulting in the reproductive success of the norm or average phenotypes.[4] This means that most common phenotype in the population is selected for and continues to dominate in future generations.

Depending on the environmental conditions, a wolf may have an advantage over wolves with other variations of fur color. Wolves with fur colors that do not camouflage appropriately with the environmental conditions will be spotted more easily by the deer, resulting in them not being able to sneak up on the deer (leading to natural selection).
  1. ^ Lemey P, Salemi M, Vandamme AM (2009). The Phylogenetic Handbook. Cambridge University Press. ISBN 978-0-521-73071-6.
  2. ^ Loewe L. "Negative Selection". Nature Education. 1 (1): 59.
  3. ^ Charlesworth B, Lande R, Slatkin M (May 1982). "A neo-Darwinian commentary on macroevolution". Evolution; International Journal of Organic Evolution. 36 (3): 474–498. doi:10.1111/j.1558-5646.1982.tb05068.x. JSTOR 2408095. PMID 28568049. S2CID 27361293.
  4. ^ Campbell NA, Reece JB (2002). Biology. Benjamin Cummings. pp. 450–451. ISBN 9780805366242.