Hopefully this paper will inspire more research involving this interesting phenotype. I'm curious about the population specific prevalence too.
For example if Northern Europeans started reproducing at a higher rate, could we say that humanity is evolving more and more lactose tolerance? I would say that would be very misleading.
My question is, does their methodology tell apart the following effects:
- The new artery is spreading across the board in various places, e.g. there is a general environmental selection pressure for random mutations in this direction, OR
- Populations that have it or don't have it are reproducing at different rates, possibly for totally unrelated reasons like socioeconomic ones.
First and foremost, their curve fitting, disguised as race-agnostic methodology, ignores the number of studies of the median artery in Africa 100 years ago (zero) and now (many).