Just like any other text, this book embodies many hidden stories. It combines different worlds and is based on the help and effort of many colleagues and friends. Although writing involves solitary journeys, I could not have realised that the secret to writing a book lies in collective work. In a sense, this book produced its networks of intellectual exchange; writing it taught me many things about work and life in academia and in the process it gifted me many friends and colleagues. The book was written, but it also wrote my life.

My interest in genetics existed before I started this project. However, my anxieties and excitement about its potentials came with my work on the Human Genome Diversity Project. Genetics became something that I found myself criticizing or defending, depending on the context that I was in. It thus became my intimate other. I attribute this involvement to the generosity of the scientists who allowed me to take a look in their kitchen and to try out some of the recipes myself. Gert-Jan van Ommen played a crucial role in this. He became involved with my research from the beginning and was a very careful reader of my work, providing me with valuable comments and suggestions. I thank him for long and insightful discussions, and for opening the doors to the community of population geneticists, which enabled me to enter the laboratories.