Figure 1From: Geographic variation in sexual selection and implications for speciation in the Barn Swallow Range map of the six barn swallow ( Hirundo rustica ) subspecies. Dashed arrows show hypothesized directions of colonization from an African common ancestor. Note the back-colonization of the Baikal region by North American swallows, which eventually gave rise to H. r. tytleri. Figure adapted from Dor et al. ([2010]).Back to article page