The lecture 2024-2025 by Prof. Lluis Quintana-Murci aims to illustrate how studies in human genetics shed light on how genetic diversity, as well as the interactions between genetics and the environment, shape our biological diversity, whether simply morphological, such as skin size or pigmentation, or associated with certain pathologies. The last two decades have been marked by a veritable genomic revolution, which has considerably enriched our understanding of the extent of genetic diversity within our species, both between individuals and between populations, and of the fundamental role of this diversity - l'inné - in the development of human diseases.
For some diseases, the role of genetics is decisive, as shown by the genetic causes of cystic fibrosis or certain cases of breast cancer. In other contexts, the impact of genetics is more moderate but still significant, notably for complex diseases such as diabetes, AIDS or autism, where numerous genes are involved. However, the distinction between innate and acquired is complex. Often, the risk of developing a disease results from the combined effects of genetic, demographic, environmental or lifestyle factors.