Redheads, rest easy: your chances of climate change-induced extinction are identical to those of people with less exhilarating hair colour. This seemingly obvious fact will no doubt drown in the current deluge of coverage declaring that gingers are genetically doomed. The source? A company that sells genetic ancestry testing.
Let’s deal with the science. Red hair is caused by changes in a single gene, and exists in the overall population at about 4-5%, making it beautifully rare. Its increased prevalence in Scots (and the Welsh and English, and other northern European populations) is probably due to a degree of isolation in an ancestral group at some point in our ancient history.
In this particular case, it is very hard to think of a way that the ginger gene might be extinguished. The selective pressure asserted in this tale is that redheads exist as an adaptation to cloudy weather in Scotland. Alas, there is scant evidence for that – scientists are still debating if the red-hair gene or, indeed, any of the genes that affect skin, hair and eye colour, spread because of a lack of sunlight, or because of some sort of mate preference, or just by offchance. Nor am I aware of any evidence that Scotland is getting less cloudy as a result of climate change. To become extinct, ginger hair would have to be a powerfully maladaptive condition, which of course it is not. It’s a very lovely condition.
Related on the SLP
Read the full, original story: Relax, redheads. You’re not about to die out
