William was the first werewolf, but was permanently stuck in werewolf form. Lycans evolved from him. They being the werewolves that could change at will.
Selene is unique. She drank the blood of the man who was the father of the 2 that originated the lycan and vampire races. She incorporated into herself the blood of an immortal. The pure essence made her immune to light. Also, look at her mouth in the movies, the fangs don't reveal themselves unless needed.
I forget his name at the moment, but the vamp/wolf hybrid can change at will just like a lycan. Since there was no need for combat after the brothers died, he changed back.
Remember, this isn't like Anne Rice's Vampire chronicles where all the members of a supernatural species are linked to the originator. The focus here is more DNA based.
Blackmoon wrote:Wait a minute.... At the end of the second one they killed both brothers,the original vampire and lycan, pretty much turning the lycans and vampires human again.
The reason I come to this conclusion is based off of both Selene and the guy that was the vamp/wolf hybrid both became normal again, because Selene stood in sunlight, her eyes turned back to their original color and her fangs were gone. The vamp/wolf hybrid also changed back to normal as soon as the brothers were dead. So if they were changed back wouldn't all the others change back as well?
I mean I'm not complaining about seeing Kate Beckinsale in that skin tight leather outfit again but they're pretty much ignoring the ending of the second movie.