How a male-killing microbe hijacked the evolution of the African Queen butterfly by Dr. Simon Martin

Speciation, the emergence of new species, occurs when 'isolating mechanisms' prevent the exchange of genes between populations. This can happen through adaptation to different environments, or through evolutionary 'accidents' that prevent interbreeding. The African Queen butterfly Danaus chrysippus, is divided into four subspecies that meet and interbreed in a hybrid zone in East and Central Africa. In this hybrid zone, and only here, the butterfly is infected by a male-killing microbe called Spiroplasma. This microbe is inherited from mother to daughter, and kills all sons. It is therefore hypothesized to create a barrier to the flow of genes between the subspecies, and could be driving their speciation. In this talk, I will show how we have used genome sequencing to investigate the barriers between the African Queen subspecies. I will then present surprising evidence that the male-killing microbe has changed the genetic makeup of the hybrid zone population, and also their color patterns. Seminar Video



I'm originally from South Africa, where I did my undergraduate and master’s degrees at the University of Pretoria. I moved to the UK for my PhD at the University of Cambridge, where I worked on the evolutionary genetics of Heliconius butterflies. There I developed a strong interest in speciation, the process by which new species form, and the effects of hybridization between species. I remained in Cambridge after my PhD on a four-year research fellowship. For the past two years I have been based at the University of Edinburgh, where I am funded by a Royal Society research fellowship. My research group works on the evolutionary genetics of lepidoptera, with an overall aim of understanding how various evolutionary forces shape patterns of genetic diversity in nature.