Detecting Local Adaptation Using the Joint Sampling of Polymorphism Data in the Parental and Derived Populations

When a local colonization in a new niche occurs, the new derived population should be subject to different selective pressures from that in the original parental population, consequently it is likely that the colonization is followed by directional selection at many loci. In such a quick adaptation event through environmental changes, it is reasonable to consider that selection utilizes genetic variations accumulated in the pre-colonization phase. This mode of selection from standing variation would play an important role in evolution of new species. Here, we developed a coalescent-based simulation algorithm to generate patterns of DNA polymorphism in both parental and derived populations. Our simulations demonstrate that selection causes a drastic change in the pattern of polymorphism in the derived population, but not in the parental population. Therefore, for detecting the signature of local adaptation in polymorphism data, it is important to evaluate the data from both parental and derived populations simultaneously.

Key Words: coalescent, local adaptation, population genetics, selection

Online ISS 1091-6490
Copyright 2008 by the Genetics Society of America
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