Science doesn't deal in proof, it deals in evidence.
How does common decent (shared common ancestors), which is a fact, eliminate the possibility of the process being guided somehow?
Guided how? Which physical law would you like to suspend?
"Guided how? Which physical law would you like to suspend?"
I am saying that you cannot demonstrate that the process has not been guided. To make that statement, which I dont believe you can honestly refute, I don't need to violate any physical law.