draggonlaady

While trying to source a quote in a comment on a previous post, I happened upon the wonderfuls site You Fail Biology Forever, which discusses overdone TV tropes and contrasts them to real life.

It is a thing of beauty! Enjoy, enjoy!

In reality, many closely related Earth species share over 99% of their DNA, but cannot produce viable offspring (and those that do are often sterile). This makes it extremely unlikely that creatures of different planets would be able to interbreed, but then again, Mars does need women.

In fictions, human beings can conceive children with any intelligent species in existence. Demons, elves, aliens, vampires, you name it — not only will a human sleep with it, they'll engender children.