This book includes 16 selected contributions presented at the 23rd Evolutionary Biology Meeting, which took place in Marseille in September 2019. The annual Evolutionary Biology Meetings in Marseille serve to gather leading evolutionary biologists and other scientists using evolutionary biology concepts, e.g. for medical research. The aim of these meetings is to promote the exchange of ideas to encourage interdisciplinary collaborations. Offering an up-to-date overview of recent findings in the field of evolutionary biology, this book is an invaluable source of information for scientists, teachers and advanced students.