Frequency-dependent selection

Frequency-dependent selection can also lead to dynamical chaos when some individuals' fitnesses become very low at intermediate allele frequencies.

[2][3] The first explicit statement of frequency-dependent selection appears to have been by Edward Bagnall Poulton in 1884, on the way that predators could maintain color polymorphisms in their prey.

[7] Clarke discussed predator attacks on polymorphic British snails, citing Luuk Tinbergen's classic work on searching images as support that predators such as birds tended to specialize in common forms of palatable species.

[15] A common misconception is that negative frequency-dependent selection causes the genetic diversity of influenza haemagglutinin (HA) glycoproteins.

This means that new mutants or migrants that have color patterns other than the common type are eliminated from the population by differential predation.

Positive frequency-dependent selection provides the basis for Müllerian mimicry, as described by Fritz Müller,[17] because all species involved are aposematic and share the benefit of a common, honest signal to potential predators.

[citation needed] Another, rather complicated example occurs in the Batesian mimicry complex between a harmless mimic, the scarlet kingsnake (Lampropeltis elapsoides), and the model, the eastern coral snake (Micrurus fulvius), in locations where the model and mimic were in deep sympatry, the phenotype of the scarlet kingsnake was quite variable due to relaxed selection.

Anvil stone, where a thrush has broken open shells of polymorphic Cepaea snails; its selection of morphs may be frequency-dependent. [ 4 ]
Müllerian mimetic species of Heliconius from South America
Harmless scarlet kingsnake mimics the coral snake, but its pattern varies less where the coral snake is rare.
Venomous coral snake 's warning coloration can benefit harmless mimics , depending on their relative frequency.