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an unusually high frequency of a gene in a particular population derived from a small set of unrepresentative ancestors.
A random difference in allele frequencies of a population founded by a small group of organisms relative to the allele frequencies in the original population.
founder effectthe result of starting a new population with a low number of individuals (founders), so that their GENE POOL may not contain the same proportions of ALLELES for a particular LOCUS as in the original population. For example, instead of containing three alleles of the ABO BLOOD GROUP locus, Australian aborigines contain no B alleles and thus no Group B or Group AB individuals are produced, a situation probably caused by a ‘founder effect’. Such small founder populations are subject to RANDOM GENETIC DRIFT.
extreme genetic drift that occurs when a new population is based on only a few individuals ('founders'). Called also founder principle.