Everyone has earwax. Technically, it's not really "wax". Instead, it's a combination of dead skin cells, hair, oil, sweat, and other secretions. Which type of earwax you have—wet or dry—is entirely determined by your genes. An AncestryDNA® test can tell you which type your DNA indicates you're most likely to have.
Dry Earwax and Wet Earwax
The two main types of earwax are dry and wet. Dry earwax is flaky and gray or tan. Wet earwax is sticky and yellow or brown. Dry earwax doesn't have cerumen, a waxy substance.
Your earwax type is linked to your origins. Dry earwax first appeared in Asia and is thus more common among Asian and Native American populations. Wet earwax is common among most other populations.
Scientists still aren't sure why Asian and Native American populations' earwax is different from the rest of the world's. One theory is drier earwax could've been an advantage to ancient populations in the frigid climates of northeast Eurasia.
The Inheritance of Earwax Types
Earwax genetics can explain why you have a certain earwax type. One significant marker in the ABCC11 gene seems to determine whether you have wet or dry earwax.
There are two versions of the gene: one codes for wet earwax, and the other codes for dry.
That means if you get a "wet" version from either your mom or dad, you'll probably have wet earwax.
If you have dry earwax, it's because both of your parents passed a "dry" version of the gene on to you. Wet earwax is a dominant trait, and dry is recessive.
Scientists think the dry earwax type became common in ancient northeast Eurasia and spread to East Asia and the Americas.
The Biology of Earwax Type
The main purpose of earwax is to protect your ears, blocking things like dirt from getting inside of them. It can fight infections because it has antibacterial and anti-fungal properties. And earwax also lubricates your ears to keep them from feeling itchy and dry.
Scientists don't know exactly why there are two earwax types. It's possible that having fewer body secretions, like wet earwax, that could freeze made it easier for people to survive in cold climates. So dry earwax became more common in areas with colder climates.
Most likely dry earwax appeared because of a AncestyDNA
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Yoshiura K-I, Kinoshita A, Ishida T, et al. A SNP in the ABCC11 gene is the determinant of human earwax type. Nature Genetics. 2006;38(3):324–330. doi:10.1038/ng1733.
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