One of the biggest promises of modern DNA sequencing methods is the ability to track the adaptation of living populations at a fine genetic scale, in essentially real time. It’s already been done in a number of experimental evolution systems: collect lots of DNA sequence data from a population, subject that population to selection, then sequence its selected descendants and compare them to the pre-selection sequences to identify genetic variants that became more common over the course of adaptation. More and more, it’s getting to be possible to do that in the—I would say—more interesting case of natural populations responding to selection by conditions we may not even know with any specificity. A paper in the latest issue of Molecular Ecology is a nice example of the possibilities from an in nature “evolve and re-sequence” study—but it also shows how much work will be necessary to truly realize the promise of the approach.
The paper, by Vincent Bourret, Mélanie Dionne, and Louis Bernatchez at the Université Laval and the Ministère des Forêts, de la Faune, et de Parcs in Québec, Canada, tests for adaptive genetic change over the course of a single generation in Atlantic salmon. Salmon are interesting as an economically important species, but their lifestyle also makes them particularly suitable for fine-scaled studies of adaptation.