Sorry, common ancestry means just what it says. That all lifeforms on earth had a common ancestor. How this ancestor came into existance in the first place does not matter a lick to the theory of evolution.
"Sorry, common ancestry means just what it says. That all lifeforms on earth had a common ancestor. How this ancestor came into existance in the first place does not matter a lick to the theory of evolution."
You missed the point entirely. The only reason why evolution would posit a universal common ancestor was because the theory is excluding other events that would create new ancestors. We have no direct evidence for a single ancestor, therefore it is either (a) a spurious claim, or (b) a deduction from something else. If it is a spurious claim, then it needs to be removed as a proven entity. Really, though, the reason it is positted is that the theory of abiogenesis used by evolutionists exclude life from occurring more than once. However, if evolution removes abiogenesis from its dogma, then it loses universal common ancestry as well.