Acceleration of Drosophila subobscura evolutionary response to global warming in Europe

The increasing risk of irreversible ecological transformation under global warming has boosted the need to understand the capacity of organisms to adapt to this change. Here, using a resurvey method of populations of the European fly Drosophila subobscura, we show that a known evolutionary response to global warming has accelerated in the past 20 years, in step with regional warming. This genetic response has come entirely by resorting pre-existing variation—and not from novel inversions—for tolerance to high temperature. Temperate populations are predicted to converge to the typical Mediterranean chromosomal composition by the mid-2050s, at which point this classic example of steep genetic cline will have vanished. Our results suggest that species with broad geographic ranges, large population sizes and high genetic diversity may have the evolutionary potential to cope with climate change. The authors resurvey data from the present, late 1960s and late 1990s to understand the evolution of European Drosophila fly populations. They show that genetic changes in temperate regions have accelerated in line with warming and come from pre-existing rather than new variation.