Evolution: Faces in a crowd

Evolution of individuality among human faces arose to avoid cases of mistaken identity in complex social groups, suggests a new study in Nature Communications.

Humans have a remarkable ability to distinguish between different individuals within a large social group. This is partly due to the diversity in facial features between individuals, which is typically much more variable than in other species that live in large groups.

Michael Sheehan and Michael Nachman use measurements of facial features and body traits to show that faces are typically far more variable in shape and layout, when compared to other features, such as hands. They also analyse a large genetic dataset of people of African and European descent and find evidence of increased variation in regions of the genome associated with facial characteristics. This finding suggests that selective pressures are operating to maintain high levels of diversity in this trait, implying evolutionary selection for facial individuality.

Similarities in these specific regions of the genome, when compared to sequences from Neanderthals, also suggest that this variation may even predate the origin of modern humans.