Professor Thomas said: "We don't know which of the many traits were advantageous in the past. It is easy to imagine that thicker hair, tooth shape, more sweat glands or some other associated skin features could have increased fitness, but for quite different reasons."
Dr Pascale Gerbault, a PhD student in Professor Thomas's group, and co-author of the paper said: "What seems unlikely is that the same traits were advantageous throughout the whole of the last 30,000 years; prior to 10,000 years ago the climate was cold and highly variable, but for the last 10,000 years it has been much warmer and relatively stable."
She added: "So perhaps one trait was favoured when it was colder and another when it became warmer. Maybe one of the less visible traits was selected early on, leading to a rise in the frequency of a more visible trait like thicker hair, which was later selected as a cultural preference."
Sijia Wang a former UCL PhD student intends to focus on that question in his new role, as a Max Planck independent research group leader in dermatogenomics at Chinese Academy of Sciences Max Planck Partner Institute for Computational Biology in Shanghai.
By leveraging the power of diverse fields, the team is piecing together the foundation for understanding how selected mutations like EDARV370A have impacted human diversity. But, the authors say, this is only the beginning.
"These findings point to what mutations, when, where and how," said Daniel Lieberman, a professor of human evolutionary biology at Harvard University and a co-senior author on the study. "We still want to know why."
|Contact: Clare Ryan|
University College London