Selection and hybridization shaped the rapid spread of African honey bee ancestry in the Americas
Fig 1
Spread of scutellata ancestry in the Americas.
Map of hybrid zones in California and Argentina, with cartoon arrows depicting the two routes of scutellata-European hybrid honey bee invasion out of Rio Claro, São Paulo, Brazil. Dates of first occurrence along the routes of invasion are from [12] [54] and [55], with approximate GPS locations extracted from google maps. Insets zoom in on each hybrid zone to show the mean GPS coordinates for each sampled population. Sampling spanned 646km in California and 878km in Argentina in the north-south direction. Genome-wide scutellata (A), eastern European (C), and western European (M) ancestry inferred using NGSAdmix for each bee are shown in a bar chart at the bottom, where each vertical bar is one bee and colors indicate proportion ancestry. Populations are arranged by latitude, with samples closest to Brazil on the right. Light fading indicates that a bee comes from the previously published California data set [34] and was collected in the field 3-4 years prior to the bees from this study. These earlier California samples include one island population, Avalon (Catalina Island), indicated by a yellow triangle. Bees from Avalon have majority M ancestry, in contrast to all mainland California bees which have predominantly A and C ancestry. The underlying maps were created by plotting geographic data from the CIA World DataBank II [56] in R [57] using ggplot [58].