It is widely appreciated that population waves have played a crucial role in the evolutionary history of many species, including humans. In parallel with Fokker-Planck descriptions of stochastic processes in physics, population geneticists independently developed methods for understanding mutations, genetic drift and selective advantage in such situations. Genetic footprints of many pioneer species are still recognizable today, and neutral genetic markers can be used to infer information about growth, ancestral population size and colonization pathways. Neutral mutations optimally positioned at the front of a growing population wave can increase their abundance via a "surfing" phenomenon. Experimental and theoretical studies of this effect will be presented, using bacteria and yeast as model systems.
