Not trying to toss a monkey wrench into the discussion here, but there are some writings that Ragnarok is a Total Reset. Ask and Embla are two humans who hide in trees (ash and elm) and when the Ragnarok is over, come out and rebuild life anew. I'm on the fence about this being a post-conversion addition, as Snorri Sturluson was a Christian monk (where we get some of the writings from). The idea, then, becomes a cyclic rather than linear progression, as many pre-Abrahamic traditions maintained.