Research over many years has examined if and how the indigenous people of Siberia evolved to adapt to the extremely harsh winter climate there. Most evidence points to three major genetic adaptations that helped people survive and even thrive in average January temperatures of -25 °C (-13 °F).
The three genes – UCP1, ENPP7 and PRKG1 – influence bodily mechanisms that control, respectively, how body fat is metabolized into energy, how smooth muscles contract and blood vessels constrict with regards to shivering, and how the body metabolizes animal fat. The positive selection for these genes is evident at different levels in different segments of the indigenous Siberian population. Taken together, however, it’s clear that over 25,000 years of habitation in Siberia, humans there became better equipped to physically cope with the cold.
Which is to say, there is clear evidence that ‘modern’ humans have not stopped evolving.
In a somewhat related discussion, the Research Institute for Humanity and Nature has a project that looks at how global warming will affect Siberia, and what that will mean in terms of human adaptation. Siberia comprises almost 10% of Earth’s land mass, and with the environment there undergoing rapid change and known ecosystems developing in unpredictable ways, researchers are asking how indigenous locals are managing in their traditional lifestyles.
So far, the answers point to a less dire assessment than perhaps expected – one study said that it was much harder to adapt to the isolation and retreat of government support and health care that followed the collapse of the Soviet Union than it has been to deal with increased flooding and declining permafrost.
My conclusion is this: We can physically adapt, more or less, to environmental challenges by altering our habits, and given enough time, our bodies are supported by evolution. Wherever possible, we are good at finding work-around solutions.
What we don’t do as well with, at least in the short to medium term, is sudden and extreme social upheaval.