Abstracts (first author)
Patterns of genomic divergence across parallel hybrid zones of mimetic Heliconius butterflies
The butterflies Heliconius erato and Heliconius melpomene are well known for their amazing mimetic similarities in colour pattern. These colour patterns vary across their geographic distribution with parallel hybrid zones in both species found between adjacent colour pattern races. Here we use RAD sequencing to investigate patterns of genome-wide divergence across two such hybrid zones of both species, in Peru and Ecuador. These data are successfully used to map loci controlling colour pattern differences between races and confirm previous findings that largely the same loci are responsible for colour pattern differences in the two mimetic species. In addition, these loci are among a handful of divergence outliers identified in the genomes, supporting the assertion that strong selection acting on colour pattern is one of the primary forces maintaining these hybrid zones. In spite of the striking parallels at the genomic level between species we do also find some previously unidentified differences. We also compare different techniques for analysis of this type of data, which we envisage being ever more widely used for the analysis of adaptive divergence in wild populations.