Insights into the role that natural selection has played in recent European human genetic evolution over the past 2,000–3000 years is revealed in a paper published in Nature Human Behaviour. The study — which identifies genetic effects associated with 755 traits that have been altered by natural selection over this time period — demonstrates the influence that this process continues to have on our genome.
Natural selection is one way in which evolution occurs, leading to small changes from one generation to the next. Previous findings have revealed how natural selection may have shaped the evolution of our species (H. sapiens), but less is known about any subsequent impacts of selection.
Weichen Song and colleagues use modern human genetic data from the UK Biobank and Psychiatric Genomics Consortium, along with ancient human genomic DNA from across Europe, to examine evidence for natural selection in European populations for the period spanning from the emergence of H. sapiens as a species to the present day. The authors suggest that the genetic effects associated with 755 complex traits — those associated with multiple genetic effects and environmental factors — have been altered by natural selection over the past 3,000 years. These include traits linked to many different genetic effects, including pigmentation, nutritional intake and several common diseases or disorders, such as inflammatory bowel disease or anorexia nervosa.
The authors conclude that although their results cannot determine whether these genetic effects have a causal impact on complex traits, and generalizability is limited by the exclusive use of European data, they could act as a foundation for future research into human genetics and evolution.