Dinosaurs prove the earth is young! No sorry this is NOT a pro-evolution post.
The problem with beginning with a theory is that you tend to try to make square pegs fit into round holes.
If something doesn't fit your preconception you discard it even if all the observations tell you that you are on the wrong track.
In archaeology and anthropology if things don't fit the theory they go into the box in the basement never to see the light of day and if you persist in telling your simple, irrefutable observations you find yourself on the unemployment line. It has happened again and again.
You have to stick with the party line or you are persona non grata.