Climate change and chromosomal inversions in Drosophila subobscura

In natural populations, the large changes in chromosomal structure occurring through chromosomal inversions show pronounced variations in frequency that often correspond to temporal and spatial climatic trends, which suggests that they may be employed to monitor the impact of global warming. Here we review and update the evidence on the association between chromosomal inversions and climate in D. subobscura, which provides one of the best studied models in this con- text. Chromosomal inversion frequencies of D. subobscura populations vary predictably with lati- tude, and this association has evolved independently in Europe and South and North America. They also exhibit clear seasonal trends that are consistent with temperature fluctuations. More importantly, latitudinal clines in chromosomal inversion frequencies seem to be responding to the global rise in mean temperatures in all continents. We analyze the relevance of these results in the light of climate change, and discuss how a better understanding of the mechanisms underlying these patterns may contribute to our knowledge on the impacts of global warming in biological systems.