I think, they are devolving. It's pretty simple, old animals are stronger than the ones we got now. You could take the dinosaurs as example. They are way stronger than the animals we got now. But that's a pretty bad example. Mh... Ah. I got one now. You see, the Wolf is a pretty strong animal, and clever, too. You see, the dog, he's just like an "evolution" of the wolf. There's only one thing that's missing: strength. The wolf is way stronger than the dog. And most-likely cleverer, too. It's the same with Yanma and Yanmega, for example. Yanma is pretty weak, but Yanmega got quite some power. So in some way, Yanma is evolving, but also devolving. But there's more devolving than evolving, so I chose devolving.