Board Thread:False Info and Speculative Discussion/@comment-4815136-20140817115322/@comment-6383956-20140902143001

Paul.rea wrote: Then this discussion is moot.

It's a show about biology and they've been consistent with their exclusion of "magical" explanations for the events presented. Being consistent about not saying "magical" doesn't mean it's biological.

In fact, according to what you're saying, the bite (or a deep enough scratch) changes the DNA of a werewolf at every level. Which is biologically impossible but, more to the point, has never been said by anyone in canon.

Once again, the answer is "we don't know but Paul's gonna make it up for us and call it canon".