I find it hilariously ironic that in a thread begun to demonstrate and explain the idiocy apparent in the question which is the title of the thread, we are subjected to the following nonsense.
Chuck77 writes:
If we descended from a common ancestor...how come we don't know who they were?
If you had engaged your brain before your fingers, the answer would have come to you in a flash. Panda has given you a great example of why your question is dumb, in fact it's even dumber than the original question. By your reasoning, if you can't tell us all about your great x 7 grandfather then he didn't exist. So spill, tell us about him, because he obviously did exist. If you can't tell us anything are we to assume that he didn't and therefore that YOU don't exist either?
Honestly, Chuckieboy, you're gonna have to raise your game a bit. It's one thing to make a statement against evolution and have that statement rebutted, it's another thing entirely to make a statement that makes you look like an utter idiot, which, if correct, proves you don't exist.
I have to assume that much of this post is going to sail right over your head and go "plop" on the wall behind you, since the idiocy of your question demonstrates a complete lack of higher thought processes. Maybe not all of us share a common ancestor with othe apes - on the evidence I'd say some share a close common ancestor with turnips.