Anyone who has ever been up a mountain will know that altitude sickness is the pits. Headache, dizziness, sickness - pretty grim when you're trying to enjoy a relaxing skiing holiday. This is due to the fact that the higher you go, the less oxygen there is in the atmosphere. You'd think, then, that people actually living at high altitudes would be pretty sick of their lives by now, but it turns out that this is not the case. Tibetan highlanders, most famously the Sherpa people, have been found to possess a gene mutation that allows them to live and work at altitudes of over 4000 metres with no ill-effects. Their genetic mutation allows the oxygen in their blood to be used highly efficiently. Rather counter-intuitively, the mutation means that Tibetan highlanders actually have less haemoglobin in their blood, in contrast to another high-altitude community, the Andeans, who have very high levels of haemoglobin to deal with the low oxygen levels. It is thought that this allows the Tibetans to avoid problems such as blood clots and strokes associated with high levels of haemoglobin. The really amazing thing about this mutation is how quickly it has spread. The gene is thought to have originated as recently as 3000 years ago (for reference, this is roughly the same time that Stone Henge was being built) and is now present in almost half the population. There is evidence to suggest that the mutation originated from homo sapiens interbreeding with another species of humans called Denisovans, which died out shortly after. The gene will have been transferred to humans much earlier on in our history, but would have become more prominent as it became advantageous to high-altitude communities. And that is living, breathing evolution right there. Want to write for What Culture Science? Click here to find out how you could get paid to write about what you love.If you love science as much as we do, like us on Facebook or follow us on Twitter for more.
