Human evolution and earwax

Cecil's Columns/Staff Reports
1

“If you would describe yourself as white or black, your earwax is probably yellow and sticky. If you are East Asian or Native American, it’s likely to be dry and white.” Cite: https://www.sciencenews.org/blog/gory-details/what-your-earwax-says-about-your-ancestry

With respect to the above, I have 3 questions :

  1. Do non human primates have different ear waxes like humans ? Are they sticky ?
  2. Can a DNA test tell if the ear wax is sticky or dry ?
  3. Is there DNA or other evidence available to show when this difference arose ?
2

As to point 2, yes a DNA test can detect the difference between the wet and dry alleles.

3

Thank you Iggy. Do you know if one or the other trait is dominant/ recessive ?

4

I’d heard this before - on the ‘It’s OK to be Smart’ YouTube channel - and was agog at it. Other than the genetics, what’s the cause? Could it be selected for? Or do these alleles select for something else and because of that succeed?

5

For something like earwax, I’m going to guess that it was just random genetic drift that got fixed in place in some bottleneck.

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Dry is recessive: Myths of Human Genetics: Earwax

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I am not disagreeing with you, but I’d think the Ear-Nose-Throat system evolved to take care of some pathogens in the air. I could be wrong but it looks like an adaptation.

8

Earwax serves a useful evolutionary function in catching dirt, pathogens, etc. before they get too far into the ear canal. As far as I know, both the dry & wet versions of earwax serve this function adequately, therefore evolution has no pressing need to select one over the other.

Possibly, the wet type is more effective in hot, humid climates (guessing, just because it seems to be more common in people descended from ancestors in those areas). Problems with excessive earwax buildup/blockages do seem more common with the wet type, but such problems don’t interfere with reproduction, so not much evolutionary effect.

9

“Do you want to have sex tonight?”

“What? I can’t hear you!”

:wink:

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Congratulations, this thread is the subject of one of Cecil’s columns!

Please see here:

11

I’m glad this was revived, since kenobi’s comment deserves some belated applause.

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Moderator Action

Moving thread from GQ to Comments on Cecil’s Columns.

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Perhaps the two kinds of earwax have different aromas, and would have some effect on evolutionary, who-to-boff decisions. I say this because of something my new dermatologist did, during his examination of me. Unlike the previous skin doc, in the same clinic, this one rubbed a gloved finger in and around my ear. He then sniffed his finger. He didn’t comment on what he found, and I gave it no more thought until today’s The Straight Dope column and the questions in this thread. (Jonathan Chance’s question, especially.)

I have another appt. with the dermatologist on August 2nd, and I’ll ask him about it then.

14

Yaaay!! Thanks Cecil, I feel honored and the write up is great too.

15

In the article at one point Cecil is skeptical regarding the utility of studying earwax.

But IIRC a number of studies recently have demonstrated that earwax can be diagnostically useful, and it may be possible to diagnose many conditions with a swab of earwax rather that a blood test (not sure everyone would consider that preferable, but anyway).

I’ll scratch around for some cites later