Relative influences of historical and contemporary forces shaping the distribution of genetic variation in the Atlantic killifish, Fundulus heteroclitus.

A major goal of population genetics research is to identify the relative influences of historical and contemporary processes that serve to structure genetic variation. Most population genetic models assume that populations exist in a state of migration-drift equilibrium. However, in the past this assumption has rarely been verified, and is likely rarely achieved in natural populations.

Microsatellite analysis of the phylogeography, Pleistocene history and secondary contact hypotheses for the killifish, Fundulus heteroclitus.

The mummichog, Fundulus heteroclitus, exhibits extensive latitudinal clinal variation in a number of physiological and biochemical traits, coupled with phylogeographical patterns at mitochondrial and nuclear DNA loci that suggest a complicated history of spatially variable selection and secondary intergradation. This species continues to serve as a model for understanding local and regional adaptation to variable environments. Resolving the influences of historical processes on the distribution of genetic variation within and among extant populations of F.