Some people look for their roots to try to understand who they are. Carles Lalueza-Fox (Barcelona, 1965) looks for them to decipher where we come from and better understand our past as a species. For more than two decades, this paleogeneticist from the Institute of Evolutionary Biology (IBE-CSIC-UPF) and current director of the Barcelona Museum of Natural Sciences has been reading the history of humanity in ancient DNA and is one of the world's leading experts. He has contributed to demonstrating that modern humans carry Neanderthal DNA and has reconstructed migrations and interbreeding of prehistoric populations. He has just published Identidad (Crítica), where he delves into a murky terrain: what DNA can explain about who we are and what it cannot.