founder effect

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founder effect

[′fau̇n·dər i‚fekt]
(genetics)
The overrepresentation of a specific allele at one or more loci in a new population that arises from a small number of individuals whose small gene pool may be unrepresentative of the parental population initially or as a result of the ensuing genetic drift.
References in periodicals archive ?
2007) assigned "Nova Scotia" or "Ontario" as the possible sources of the founding population, based on personal communication, and Fasanella et al.
To find out how long ago and how many Indonesian settlers there when the island's population was founded, the team ran various computer simulations that started out with different founding populations at different times until the results matched their real-life data.
Therefore, any founding populations are ancestral to what then became Native American people and cultures as we know them today.
A relatively small founding population was fruitful and multiplied--aided in the 19th century by polygamy, which allowed husbands to have more than one wife.
Accordingly, the distinct linguistic and cultural groups emerged after the expansion and radiation of the founding population throughout North, Central, and South America.
Finns are a good example: Finland had a small founding population, so some mutations are found in Finns more frequently than in other Europeans.
Recently colonized areas would be expected to show less genetic diversity than areas with long-established populations, particularly if the effective size of the founding population was low.
Nielsen's study, which argues for one founding population, finds that about 13,000 years ago, Native Americans split into two groups, one that spread through North America and continued into South America, and another that remained in North America.
Deviations from a 1:1 sex ratio (Crow and Kimura 1970), variation in reproductive success among colonizers (Wright 1938) and the probability of common origin of the colonizers (Whitlock and McCauley 1990) further reduce the effective size of the founding population and increase the effect of the founding event.
While their North American populations may have overlapped for only a few generations, members of the Dorset and Thule cultures shared genetic similarities that point to a common, founding population in Siberia.
These observations can be explained by the postglacial colonization of East Lake by a single founding population of Acadian origin characterized by the original haplotype 25 still found in the lake, followed by the local genesis of haplotype 106, the radiation of the two morphotypes through disruptive selection, and the development of their partial reproductive isolation.
A geneticist armed with computer simulations of prehistoric populations says that only about 200 to 300 people crossed the ice age land bridge from Asia to become the founding population of North America.