[This article mentions the out of africa theory which I don't really buy into. But otherwise, the info herein is fascinating. We are the true snow people.
Our environment shaped our bodies – that is basically how evolution works. Only those who are fitting in a particular environment survive to procreate. Scientists from UCL researched the gene, called, TRPM8, which allows humans to detect cold. They found that this exact gene is what allowed early Europeans to adapt to cold weather.
Ability to accurately feel the cold only when it becomes dangerous is very important to people who live in the North. Image credit: Havardtl via Wikimedia (CC BY 4.0)
There is only one known receptor, allowing humans to detect cold. It is also triggered by menthol, which is why it gives us that refreshing sensation. TRPM8 gene is what encodes this receptor and it is found at highest frequency in people from Northern European descent. In other words, people who lived in colder climate, feel cold weather with higher precision, which could be what allowed humans to survive in this harsh environment. It is also quite counter-intuitive, because one could think that people feel less cold if they are adapted to polar winters, but don’t rush with such assumptions. Scientists say that 88 % of Finnish people carry this genetic variant, while only 5 % of Nigerians have it.
This gene can be traced back to 25 thousand years ago, when the climate in Europe was much colder. TRPM8 is also linked to a slightly higher risk of migraines, but scientists are still not sure what to make of it. Humans left Africa within the last 50,000 years and started moving towards colder Europe and Asia, where they had to adapt to cooler temperatures. This new colonization meant that people started developing genes, allowing them to respond to cold weather. While their cold detection capabilities grew, people also learned to ignore slight cold, which could be perceived as not-dangerous. And so TRPM8 variant reduced the sensation of pain and yet allowed people to succeed in these low-temperature conditions.
Both extreme cold and migraine are related to pain, so maybe there is relation there, but again, no one is sure about that. Dr Aida Andres, supervisor of the study, said: “Most genetic variants have very similar frequencies across human populations, so it was surprising to see this one with very low frequency in some populations in warm climates and very high frequency in populations in northern Europe”.
Ability to feel cold is very important. It warns us to make sure to get warm again – get warmer clothing, start a fire or just go inside. However, once you adapt to cold, you can survive colder temperatures without immediately looking for warmth. This is what that gene variation is all about – adapting to existing conditions and remaining safe.