When I was in college a Korean American friend confided to me that his roommate had an issue. He had seen a q-tip in the waste-bin, and what was at the end of it was shocking to him. What my friend was describing was wet earwax (Google it yourself if you want to see it). As this was the first time he was living with a non-Korean he had assumed that everyone’s earwax was dry, like his own. The maps above and to the left show you the frequencies of the allele which has an extremely strong correlation with this trait. In Korea the frequency of dry earwax is close to 100%. Since the expression pattern for dry earwax is recessive, you need two copies of the derived allele, so in any population where the ancestral variant exists in appreciate frequencies you’ll have the wet variant of the trait.
This is why in 2006 a Japanese group published research in this area, A SNP in the ABCC11 gene is the determinant of human earwax type. A substantial minority of Japanese happen to have wet earwax. And it turns out that wet earwax has some other associations of interest.
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Read the full, original story: Why the Japanese Think Westerners Smell Bad (Well, One Reason)
