Phylogeny and comparative analysis of color pattern evolution in a Mexican-Central American Bombus (Pyrobombus) species complex

Color pattern polymorphism is a dominant theme in animal evolution. Bumble bee (Bombus) color pattern variation provides an unusual opportunity to understand the evolutionary processes that drive pattern polymorphism due to striking geographic color variants. Worldwide, different color patterns converge in an area with other species to form stunning aposematic mimicry complexes. In spite of their potential to elucidate processes underlying Müllerian mimicry, less than a handful of studies have examined adaptive and genetic bases of color pattern in bumble bees. Bombus ephippiatus, widespread throughout Mexico and Central America, possesses highly variable color patterns across its range, from lowland to montane habitat. We examine the molecular phylogeny of B. ephippiatus populations and of sister species, B. wilmattae and B. impatiens, with the aim of distinguishing species boundaries and identifying correlations between color pattern and phylogeny, habitat and geographic isolation. We apply DNA sequences from four genes to resolve the species level phylogeny and to gain insight into the population structure of B. ephippiatus.