A major undertaking in evolutionary biology is to link changes in genes to changes in appearance and understand the evolutionary changes that lead to adaptation and speciation. Here I will give an overview of our work on the brightly coloured Heliconius butterflies. Among these butterflies, a great diversity of wing patterns are controlled by just a few genes of major effect, each with a diversity of regulatory alleles. Changes in colour pattern contribute to speciation, but need to be associated with corresponding mate preferences to generate assortative mating.
The genetic basis for these mate preferences has a similar genetic basis to wing pattern, with just three major loci controlling mate preference between H. melpomene and H. cydno, and some evidence for a similar functional modularity as seen in wing pattern. Finally hybridisation can play an important role in shuffling these genetic variants into new combinations, rapidly generating new diversity. In summary, evolutionary changes in animal form commonly involve changes in the regulatory switches that control gene expression, and just a handful of loci of large effect can control diversity across a radiation. I will also discuss our recent fieldwork in Colombia and the implications of the peace process for conservation in Colombia
