Why is evolution hiding?

[popeyespappy]

Shouldn't we still have half reptile/half mammal?

No. For one thing there was probably never such a thing. Sure there was a halfway point although most people would probably be hard pressed to identify that species as the halfway point even if it was chewing on their genitalia at the time. Halfway would be subjective to even an expert in the field. Instead what we would have seen would be a reptile that slowly evolved mammal like features over multiple generations.

For example if you stood back to back with the chimpanzee at your local zoo. Beside each of you we lined up your mothers, their mothers, their mothers mothers and so on until each line reached all the way back to your last common ancestor. Then if a stranger looked at each individual in both lines starting at you and working their way back to the common ancestor then started back up the other line until they reached the living chimp the chances are they would not be able to identify the point in either line where homo stopped or pan started.