Apostatic selection
Encyclopedia
Apostatic selection is frequency-dependent
selection by predators, particularly in regard to prey that are different morphs of a polymorphic species
that is not a mimic
(non-mimetic) of another species. It is closely linked to the idea of prey switching
, however the two terms are regularly used to describe different aspects of the same phenomenon. Apostatic selection has been used by authors looking at the differences between different genetic morphs. In comparison, prey switching has been used when describing the choice between different species.
The idea links up with the concept of "search image" from Luuk Tinbergen
, whereby - through experience - a predator is considered to have developed a particular skill or capacity to spot prey items of typical appearance (mainly pattern), to the point where typical specimens are even taken disproportionately to their actual abundance within the population. Conversely, specimens of unusual appearance are less likely to end up as part of a predator's diet than would be "justified" if consumption of food items was related to their abundance within the population in a straightforward way. In consequence, there are greater-than-"expected" chances of individuals within a population that are of non-typical appearance passing on the genes
controlling that appearance to the next generation.
Frequency dependent selection
Frequency-dependent selection is the term given to an evolutionary process where the fitness of a phenotype is dependent on its frequency relative to other phenotypes in a given population. In positive frequency-dependent selection the fitness of a phenotype increases as it becomes more common...
selection by predators, particularly in regard to prey that are different morphs of a polymorphic species
Polymorphism (biology)
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
that is not a mimic
Mimic
In evolutionary biology, mimicry is the similarity of one species to another which protects one or both. This similarity can be in appearance, behaviour, sound, scent and even location, with the mimics found in similar places to their models....
(non-mimetic) of another species. It is closely linked to the idea of prey switching
Prey switching
Prey switching is frequency-dependent predation, where the predator preferentially consumes the most common type of prey. The phenomenon has also been described as apostatic selection, however the two terms are generally used to describe different parts of the same phenomenon. Apostatic selection...
, however the two terms are regularly used to describe different aspects of the same phenomenon. Apostatic selection has been used by authors looking at the differences between different genetic morphs. In comparison, prey switching has been used when describing the choice between different species.
The idea links up with the concept of "search image" from Luuk Tinbergen
Luuk Tinbergen
Luuk Tinbergen was a Dutch ornithologist and ecologist.Tinbergen was the youngest of three eminent brothers — both Jan and Nikolaas won Nobel Prizes, for economics and physiology or medicine, respectively.He was appointed in 1949 by Gerard Baerends to the University of Groningen, where he...
, whereby - through experience - a predator is considered to have developed a particular skill or capacity to spot prey items of typical appearance (mainly pattern), to the point where typical specimens are even taken disproportionately to their actual abundance within the population. Conversely, specimens of unusual appearance are less likely to end up as part of a predator's diet than would be "justified" if consumption of food items was related to their abundance within the population in a straightforward way. In consequence, there are greater-than-"expected" chances of individuals within a population that are of non-typical appearance passing on the genes
Gênes
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...
controlling that appearance to the next generation.