I work on understanding how humans and other species differ at the genetic level, and how this reflects events in our past. I’ve developed methods that analyse DNA differences to understand human history, our past movements, and mixing events. I am also investigating the biology of how DNA differences arise, are shuffled during reproduction, and can then impact fertility and even lead to the origin of new species. I was trained in Oxford as a mathematician, and then moved gradually towards using statistics to understand the patterns in our DNA. I have always loved the idea that a huge amount of information is present in the DNA of almost every cell in our body: but it is in the form of a complex code. What I enjoy is the challenge of finding ways to crack this code, often within a team of researchers. Our work on human ancestry in the UK and worldwide has attracted international media interest, and has featured in several UK exhibitions.