Do you really not know?
French and Italian both evolved out of Latin. Does it surpise you to hear that no people speak Latin as their first language?
Come on, this is elementary stuff.
I see you weren't able to clear this up.
Latin isn't spoken as a first language because an outside source (Celts) stepped in and altered it.
The language did not change of itself (heck, the later Roman period saw a revival of "true" latin, in an effort to keep it "correct" and "universal".)
An outside force changed it, and adapted it.
But the fact remains, we still use Latin to this day. (whether or not it is a "first language" the tangible evidence is still there)
So answer the question, especially given your recent answer: Why doesn't the ancestor still exist?