In an attempt to get to the bottom of an ancient mystery, a new video released Monday by the YouTube series SciShow offers theories on why we have butt hair.
Our hirsute-y booty may simply persist through the centuries because there's "no significant evolutionary pressure against it," host Hank Green explains in the viral clip above. In other words, it's not getting in the way of humans procreating.
Or, perhaps, the growth around our anus generates more smell down there, thus enhancing our "scent communication," Green asserts. It may even reduce skin-on-skin friction when we run or walk.
The video reveals that science hasn't done much study into the matter.
But less-scientific types have. One hypothesis often passed around is that the rectal hair muffles farts. No, seriously, the theory gets hotly debated from time to time on social media.
We're just glad we're not there for the actual research.