Founder Effect

The founder effect refers to the phenomenon in which a subset of a population moves to and colonizes a new patch or habitat. This immigration often creates a genetic bottleneck because the individuals that arrive in a new area may not accurately represent the allele frequencies observed in the founding population1. The percentage of these immigrating individuals may be carriers of a recessive trait that results in proliferation of this genotype amongst the new population. This phenomenon has been documented in human populations settling in new areas around the globe, in crop plants introduced to new locations, and has been debated as an important factor in determining success of invasive species. The founder effect was thought to play an important role in the genetic diversity of invasive species, where in many cases, an introduction consists of one or few individuals from its native habitat. Recent advances in DNA technology through use of DNA barcodes and molecular markers have enabled scientists to determine the genetic relationship of invasive populations to their founding populations. This technology has revealed that many invasive species in North America were the result of multiple introductions2. However, each individual introduction may have localized effects on the genotype of the population present in that area.

 References 1O’Neil, D. 2014. Small population size effects. Palomar College. Available from: . Accessed 8 March 2015.

2 Bossdorf, O., H. Auge, L. Lafuma, W.E. Rogers, E. Siemann and D. Prati. 2005. Phenotypic and genetic differentiation between native and introduced plant populations. Oecologia 144: 1-11.