Neither one of them has a DNA test kit at hand?
The "can't travel into your own lifetime" meme always struck me as shit. My atoms were around a billion years ago and will be around a billion years from now. WTF difference does it make if they're organized into "me"?
Not one of Stan's better ideas.
Especially since we've got a concurrent thread where Stan claimed Marvel always made "sound science" the basis of their stories.