Joachim Krug studied physics in Göttingen and Munich, and received a doctoral degree in theoretical physics from the LMU Munich in 1989. After postdoctoral research appointments at the IBM Thomas J. Watson Research Center in Yorktown Heights (NY) and Forschungszentrum Jülich, he became a professor of theoretical physics at the University of Essen in 1996 and joined the Institute of Theoretical Physics at the University of Cologne in 2004. Krug has made important contributions to nonequilibrium statistical physics, most notably in the context of random growth processes and stochastic transport. In recent years, his research has focused on understanding the genetic basis of complex biological adaptations. Combining mathematical modeling with the analysis of empirical data sets, his group has explored the epistatic interactions between mutations occurring at different loci as well as the interactions between mutations occurring at different times during adaptation.