Abstract: The identification of genes that underlie recent evolutionary change can provide insights into the evolutionary process. One discovery has been the general importance of introgression in generating evolutionary novelty. We have studied introgression between two species of crop pests that have recently found themselves in contact in Brazil after the invasive Helicoverpa armigera came into contact with native H. zea. We have used whole genome sequencing of over 1000 moths to demonstrate that these species retain their identity despite ongoing hybridization, but genes for critical pest traits such as insecticide resistance have moved between the species. Of particular concern is the introgression of genes for Bt toxin resistance into H. armigera, a potentially major threat to global food security.

Another general discovery has been the importance of structural variation as a source of genetic novelty. TE insertions and gene duplications are common mutations that can generate major phenotypic changes. We have shown that wing pattern polymorphism in the wood tiger moth is caused by an extra copy of a pigmentation gene, named valkea, while colour patterns in Heliconius butterflies are caused by TE insertions that influence gene regulation. In the light of increasing evidence for variation between individuals in gene content (the ‘pangenome’), we are studying variation in gene function between recent gene copies of digestive enzymes in the black soldier fly.