Gene Duplication and Divergence of Long Wavelength-Sensitive Opsin Genes in the Guppy, Poecilia reticulata - Corey T. Watson; Suzanne M. Gray; Margarete Hoffmann; Krzysztof P. Lubieniecki; Jeffrey B. Joy; Ben A. Sandkam; Detlef Weigel; Ellis Loew; Christine Dreyer; William S. Davidson; Felix Breden (Journal of Molecular Evolution, 2011)