It turns out, at least according to a currently unpublished and un-peer-reviewed study, anuses, from which you dispel poop, might have originally been used to dispel sperm.
That means that our anuses might have begun their evolutionary journeys as a male sex organ.
What would eventually evolve into an anus in more complex animals was originally a reproductive hole.
The sperm just got a free pass through the same tube that poop would travel through.
The First Buttholes Might Have Released Sperm Instead of Poo.
While xenacoelomorphs use their mouths for everything, from eating to poop, males also have a separate hole for sperm—a “gonadopore,” to be specific.
There is a chance that your asshole was once your sperm hole. »
