Peppered moth industrial melanism in continental Europe

Industrial melanism in the peppered moth has served as an important case study of contemporary natural selection in response to an anthropogenic environmental change. Here, we show that the melanic allele that swept through 19th century industrial Britain (carb-TE) did not crossover into continental Europe. Instead, several alleles appear to underlie industrial melanism on the continent, dominated by one variant in the Low Countries and western Germany, and another (sollichau) in eastern Germany, Czechia and Poland. Our analysis of museum samples from Brussels and Netherlands suggests that, even at the height of industrial melanism in the early 1900s, the darkest two morph categories (F and G) were each associated with two or three alleles. The polyallelic soft sweep underlying melanism in continental Europe contrasts to the simple hard sweep of a single melanic allele observed in Britain.