Reminds me of this movie......When Women Had Tails 1970.
Here’s my theory:
Humans had tails.
The longer the tail, the easier it was for a predator to catch.
So having a shorter tail was good for survival.
The females began to see short tails as preferable to long tails, so they chose to mate with shorter and shorter tails.
Heads you win, Tails you lose.
Eventually all the long tails died out or were eaten by predators.
That’s my tale of tails.......................