Figure 5 : Calfee et al. (2020) studied replicate geographic ancestry clines in invasive honey bees (Apis mellifera ). A) In 1957, western honey bees derived from African populations (A. m. scutellata ; ‘scutellata’hereafter) escaped from a captive breeding programme in Rio Claro, São Paulo. Scutellata populations both outcompeted and hybridized with honey bee populations from Europe (previously introduced to the Americas), forming invasive hybrid scutellata -European populations. Replicate North and South American invasion routes (indicated by arrows) of hybrid populations are shown with pink arrows, with dates of first occurrence indicated. B) Geographic clines in genome-wide ancestry. Curves are logistic cline models of ancestry predicted by latitude, with dotted horizontal lines indicating the latitude at which the model predicts 50% scutellata ancestry.C) Genomic location of scutellata ancestry in the two hybrid zones shown in (B). Dashed line indicates mean scutellataancestry. Parallel peaks in excess scutellata ancestry, where selection has outweighed migration to ‘push’ scutellata alleles to high frequency hundreds of kilometres past the expected cline centre, occur in chromosomes 1 and 11. Figure adapted from Calfee et al.(2020).