Recent natural selection in a wild bird Many studies have found evidence of rapid evolution in response to environmental change. In most cases, there has been some suggestion of which traits might be most responsive ahead of time. Bosse et al. turn this approach on its head by using genomic regions with a signature of selection to identify traits that are changing. In great tits ( Parus major ) in the United Kingdom, genomic regions showing selection invariably contained genes associated with bill growth. Indeed, U.K. birds not only have longer bills, but these longer bills are associated with increased fitness. These changes likely reflect an increase in domestic garden bird feeders over the past several decades. Science , this issue p. 365