"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)." Climates world-wide are changing at an unprecedented rate, especially in temperate and polar regions of the earth such as North America. The non-biological effects of climate change are seen in melting glaciers, rising sea levels, earlier springs, longer growing seasons and later falls. The biological effects of climate change are seen as shifts in animal populations towards the poles and as shifts in the timing of development, reproduction, migration and hibernation. Animals interpret and prepare for seasonal change primarily by the use of light (day length): shorter days are a highly reliable signal for the coming of winter, longer days for the coming of summer. This proposal concerns how animals respond genetically, that is, evolve, in response to climate change. This lab has produced the first genetic map of response to day length and this proposal will show whether evolutionary change in response to day length occurs through alteration of existing genes or involves the recruitment of new genes. The genes that are identified as important in this grant will provide the foundation for identifying the genetic response of animals to rapid climate change in general. Knowing the correct mechanisms of genetic response is important for predicting and mitigating the spread of vectors of disease from tropical to temperate zones, for evaluating the efficacy of introductions of predators and parasites for biocontrol, for agricultural development and for conserving biodiversity. This laboratory serves as a spokesman on the genetics of climate change at the national and international levels and serves as a resource to health agencies concerning vector-borne diseases worldwide. This lab has trained several hundred undergraduate researchers over the last 30 years, some of whom have gone on to become professors at major research institutions, and others who have become physicians, biomedical researchers, applied biologists, lawyers, journalists and teachers. All leave the lab with an intense appreciation of basic research and its contribution to human welfare and the environment.