I come from the Michael Behe school if ID. I accept common descent, by which I mean universal common ancestry. It seems to be the consensus view in science, it seems reasonable to me, and I don’t have any compelling reasons to doubt it.
But could I actually defend my belief in common ancestry if asked? All living organisms share certain features in common. Organisms leave offspring. Therefore, universal common ancestry. That sounds pretty weak, I admit. I need to do better.
I don’t believe that new organisms appear out of thin air, so to speak. I accept that the organisms of today are the offspring of prior organisms. Even young earth creationists accept common descent prior to the flood and common decent after the flood, though they resist the idea of universal common ancestry. I still haven’t figured out how and where they draw the lines though, so why should I draw a line that I cannot defend. Therefore common ancestry. That still sounds pretty weak, I admit. I still need to do better.