BioConcepts

founder effectGründerprinzip (ger.)

• The principle that when a small sample of a larger population establishes itself as a newly isolated entity, its gene pool carries only a fraction of the genetic diversity represented in the parental population. The evolutionary fates of the parental and derived populations are thus likely to be set along different pathways because the different evolutionary pressures in the different areas occupied by the two populations will be operating on different gene pools. (Oxford Dict. of Genetics 2007)
  category evolution

  1942

  The reduced variability of small populations is not always due to accidental gene loss, but sometimes to the fact that the entire population was started by a single pair or by a single fertilized female. These »founders« of the population carried with them only a very small proportion of the variability of the parent population. This »founder« principle sometimes explains even the uniformity of rather large populations, particularly if they are well isolated and the borders of the range of the species.

  Mayr, E. (1942). Systematics and the Origin of Species: 237.

  1982

  founder effect That only a small fraction of the genetic variation of a parent population or species is present in the small number of founder members of a new colony or population; founder principle.

  Lincoln, R.J., Boxshall, G.A. & Clark, P.F. (1982). A Dictionary of Ecology, Evolution and Systematics: 95.