Founder effect

The founder effect, Eng. Founder Effect, describes a genetic abnormality an isolated population or founder population (eg, on an island ) from the parent population (eg on the mainland). This discrepancy arises because of the small number of existing alleles of the individuals involved in its creation and not due to different selection criteria.

This effect was first described by Moritz Wagner in his 1889 published book The Origin of Species by spatial separation. Under its present name was mentioned by Ernst Mayr in 1942 in his book Systematics and the Origin of Species from the Viewpoint of a Zoologist.

The founder effect has significantly lower genotypic and phenotypic variability of the offspring result, as the founder individuals represent the gene pool of Output incomplete in general. This results in decreased chances of survival after onset of extreme environmental conditions and a lack of raw material for the genetic selection can result. According to the present in the founding population the population of alleles can be sensitive to more or less purging. The founder effect can thereby contributing to facilitate extinction of small, isolated populations. Many of the remaining populations in the wild in the surviving or rescued in conservation breeding animal and plant species are subject to the founder effect.

The fixation probability of an allele is generally equal to its initial allele frequency. This can occur by mutation, a new allele, as this occurs once in N under 2N alleles in diploid individuals. The allele frequency of the new allele is therefore 1 / ( 2N), and this is also the probability that this allele will prevail. Therefore, advantageous alleles can enforce sometimes easier in small populations than in large ones.

The founder effect can in some cases lead to the emergence of new species ( speciation ). In the breeding of pedigree dogs and pedigree cats he can be a cause for the occurrence of race- specific genetic diseases.