Founder Effect

In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, using existing theoretical work by those such as Sewall Wright. As a result of the loss of genetic variation, the new population may be distinctively different, both genetically and phenotypically, from the parent population from which it is derived. In extreme cases, the founder effect is thought to lead to the speciation and subsequent evolution of new species.

In the figure shown, the original population has nearly equal numbers of blue and red individuals. The three smaller founder populations show that one or the other color may predominate (founder effect), due to random sampling of the original population. A population bottleneck may also cause a founder effect even though it is not strictly a new population.

The founder effect is a special case of genetic drift. In addition to founder effects, the new population is often a very small population and so shows increased sensitivity to genetic drift, an increase in inbreeding, and relatively low genetic variation. This can be observed in the limited gene pool of Iceland, Faroe Islands, Easter Islanders and those native to Pitcairn Island. Another example is the legendarily high deaf population of Martha's Vineyard, which resulted in the development of Martha's Vineyard Sign Language.

Read more about Founder EffectFounder Mutation, General, Serial Founder Effect, Founder Effects in Island Ecology, Founder Effects in Human Populations

Other articles related to "founder effect, founders, effect, founder, founder effects":

Founder Mutation - General
... The founder effect is a special case of genetic drift, occurring when a small group in a population splinters off from the original population and forms a new one ... When a newly formed colony is small, its founders can strongly affect the population's genetic makeup far into the future ... for many generations, effectively amplifying the drift effect generation after generation until the population reaches a certain size ...
Founder Mutation
... In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population ... In extreme cases, the founder effect is thought to lead to the speciation and subsequent evolution of new species ... The three smaller founder populations show that one or the other color may predominate (founder effect), due to random sampling of the original population ...
Introduction To Evolution - Genetic Drift - Founder Effect
... The founder effect occurs when a small group from one population splits off and forms a new population, often through geographic isolation ... The founders of the population will determine the genetic makeup, and potentially the survival, of the new population for generations ... One example of the founder effect is found in the Amish migration to Pennsylvania in 1744 ...
Founder Effects in Human Populations
... Due to various migrations throughout human history, founder effects are somewhat common among humans in different times and places ... The French Canadians of Quebec are a classical example of founder population ... However, the genetic contribution of French founders is predominant, explaining ~90% of regional gene pools, while Acadians explain 4%, British 2% and Native American ...

Famous quotes containing the words effect and/or founder:

    The first general store opened on the ‘Cold Saturday’ of the winter of 1833 ... Mrs. Mary Miller, daughter of the store’s promoter, recorded in a letter: ‘Chickens and birds fell dead from their roosts, cows ran bellowing through the streets’; but she failed to state what effect the freeze had on the gala occasion of the store opening.
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    Ben Jonson (1572–1637)