Your butthole had a very different role in the ancient past, new study suggests “We take our own anuses for granted. While they may not be able to fire out our guts as a defense like some animals we could mention, or disappear and reappear when needed, like the sea walnut, they are a pretty great solution that evolution has come up with for expelling waste. But they are not universal. Some animals, including this ancient beastie, can live well enough without one, if you call expelling your waste (poop) out of your mouth day after day ‘living’. … Scientists believe that the mouth and gut evolved before the anus, but it has been debated for over a century how the anus evolved and what from. In new research titled The xenacoelomorph gonopore is homologous to the bilaterian anus, scientists found evidence that it may have evolved from an orifice to release sperm. Your butthole may have been your spermhole.”