Smell

To some people, cilantro tastes like soap. Studies show 4-14% of people carry a variant of the olfactory receptor gene OR6A2 that makes them smell cilantro's aldehyde compounds as stronger, soapy odors. It's a genetic smell reaction, not a taste difference.

The earthy smell after rain has a name: Petrichor. Its core is Geosmin, a molecule from soil Microorganisms that the human nose catches at just 5 parts per trillion—said to beat a shark smelling blood in water. Perhaps a trace of ancestors who sniffed out water on dry land.

98% of Korean people carry a mutation in the ABCC11 gene that makes body smell nearly undetectable, and 99% have dry, flaky earwax. In contrast, 97% of Europeans and Africans have strong body odor and wet earwax. A single gene variant produces both differences simultaneously.