Different Avatar and Signature question...

[FrogInABlender]

When I go and change my avatar or signature, it changes it on every post I've ever made.

Is there a way to make those changes only be effective for FUTURE posts and not be retroactive?

[WashingtonBay]

No - they aren't saved with each post, they're saved with 'you'. So when you change them, it changes it everywhere.