Meeting Abstract
Variation in bumble bee color patterns is well-documented within and between species. Identifying genetic mechanisms underlying such variation may be useful in revealing evolutionary forces shaping rapid phenotypic diversification. The bumble bee Bombus bifarius is widespread across western North America, where populations exhibit regional variation in abdominal color forms, ranging from red-banded to black-banded phenotypes and including geographic and phenotypic intermediates. We sequence populations from a spatial and color pattern transect across the B. bifarius range using RNA sequencing and RAD-tag sequencing. We use this large high-throughput sequencing data set to first resolve the phylogeography and species-level divergence among geographic color forms. We then apply genome scans to identify genome regions associated with color pattern differentiation. Results have implications for the taxonomy of B. bifarius and the role of phylogeography for color pattern divergence. Genome scan results also reveal a candidate pigmentation gene that suggests the power of natural selection to make use of existing genetic mechanisms in novel evolutionary contexts to promote phenotypic differentiation.
