May 27 2009

12:00 LSB 2320

Dmitri A. Petrov
Dept. of Biology, Stanford University

Adaptation in Drosophila


Genetic variation within and between species has long been attributed to selectively neutral evolutionary processes. Recent studies, however, estimate that as many as 60% of protein-altering substitutions and 30% of the substitutions at regulatory sites between Drosophila species are adaptive. I will describe population genomic studies lending credence to these estimates and further suggesting that a substantial portion of these adaptations are driven by strong selection. I will then describe investigation of recent adaptive events in D. melanogaster showing that adaptation is a much more complex process than is generally modelled and that population genomic studies are likely to substantially underestimate the amount of adaptive variation within species. We also argue that adaptation may not be mutationally limited as generally assumed, leading to very fast generation of even complex adaptive genotypes through de novo mutation.















































































































































































































































































































































































































































































































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