Fanged deer- or rather, tusked deer.
Aside from generally just being deer with great honkin’ tusks on their faces, the evolutionary history of these guys is really weird.
What is chase-away selection?
In preparation for answering this question I dipped my toes back into the cesspool of sexual selection theories and MAN is it just a hot sweaty mess. Utterly fascinating, of course, but just a mess.
Ok, so chase-away selection theory. To understand where it comes from, you’ve got to understand a few basic things about sexual selection itself.