Fig. 1From: Population genomics of rapid evolution in natural populations: polygenic selection in response to power station thermal effluentsSampling locations and triad design. Each thermal effluent population (red markers) is surrounded by two reference populations (blue markers). The northern triad (a) is the Brayton Point generating station population and its references. The southern triad (b) consists of the Oyster Creek nuclear generating station population and its references. Map data are drawn from US Department of Census and visualized using the maps package in RBack to article page