Speaker Affiliation :
Date(s) - 24/06/2015
11 h 00 min - 12 h 00 min
Adaptation lies at the heart of Darwinian evolution. Natural populations are constantly faced with environmental changes that force them to either adapt or go extinct – a problem that is aggravated by human-induced global change. Therefore, increasing our understanding of the adaptive process is important for both basic and applied research.
Accordingly, numerous studies have tried to provide a formal framework for the description of the adaptive process. Out of these, two complementary modeling approaches have emerged: While so-called adaptive-walk models consider adaptation from the successive fixation of de-novo mutations only, quantitative genetic models, on the other hand, assume that adaptation proceeds exclusively from pre-existing standing genetic variation. The latter approach, however, has focused on short-term evolution of population means and variances rather than on the statistical properties of adaptive substitutions.
Thus, I will here address what has been described as « the most obvious theoretical limitation when describing the adaptive process » and propose an analytical framework for the genetic basis of adaptation from standing genetic variation in terms of the effect-size distribution of individual alleles.
This approach addresses one of the central questions in this context: From the multitude of standing genetic variants segregating in a population, which are the ones that ultimately become fixed and contribute to adaptation, and how does their distribution differ from that of de-novo mutations?