To start things off, I'm going to gush a little bit about Monster Hunter. You're probably sick of me gushing about MH, but I'm going to continue doing it anyway, so tough shit. ;P Not only because it is one of my favorite series, but also because it actually includes in it's lore my favorite scientific theory: Evolution by Natural Selection.
That should surprise you, and not just because of the ridiculous political controversy around evolution. MH is a fantasy genre game, and the fantasy genre tends to make meddling gods and divine creations the default. And in any case, any game that throws the word "evolution" around tends to not use the term correctly, and instead be talking about something akin to Pokemon's magical metamorphosis, or something like Spore's god-simulations. But not Monster Hunter.
Despite it's obviously Japanese anime inspired roots, with all the physics-bending, concessions for gameplay (and humor,) and completely impractical weapons/armor one would expect from such a background, MH features a number of surprising mundanities which make the series so appealing to me. Not the least of which being the way it treats the monsters themselves. There's nothing really magical about them, at least in the context of the game world, they're just animals. Some may be extremely powerful, and feared/revered as gods by the locals, but they are still just mortal beasts. They have predator/prey relationships, they fight for territories and mates, they breed and raise their young, and they share common ancestors with one another, with no meddling deities mentioned anywhere. They are grouped into categories by the scholars of the MH world in much the same way naturalists cataloged and categorized real animals on Earth prior to the discovery of DNA.
For example, this monster, called Akantor

is classified as a "Flying Wyvern." The same as this fellow, Rathalos, MH's mascot:

"But he has no wings!" you say. No, Akantor does not have wings. Why is he classified as a flying wyvern if he cannot fly? Because he is descended from flying wyverns. He has vestigial, backwards-pointing wing claws on his forearms. He probably evolved in much the same way that this fellow, the Tigrex, is currently evolving:

While Tigrex can still fly, they rarely do so. Instead they ambush and chase their prey on the ground, running with their highly developed forelimbs.
Birds even evolved from theropod dinosaurs... er... sorry, theropod-like "bird wyverns", like the Jaggi

And there are more than just the scaley, dragony monsters pictured above. There are insects and arthropods and crustaceans, "piscine wyverns" closer to fish, and mammalian creatures, of which there are a number of apes which are the presumed group from which humans evolved.