Museum specimens uncover the past, present and future

The southwest of North America is among the most biodiverse regions of the world, characterized by a unique community of organisms adapted to mild, wet winters and hot, dry summers. This extraordinary biodiversity hotspot is also among the regions that have been strongly affected by climate change in the past decade, as is exemplified by the increasing fires in the state of California, in the United States¹. Recent technological advances in DNA sequencing are now allowing scientists to ask the question of how natural populations might respond to ongoing climate change impacts. Now, reporting in Nature Climate Change, Turbek et al.² compare current populations of willow flycatchers (Empidonax traillii) with those from hundreds of years ago that are stored in museum collections. By studying the genetic composition of the populations across time and space, Turbek et al. suggest that the current population in California shows evidence of adaptation, particularly in the genes associated with changing climatic conditions, which may have important implications for further adaptive change.