On Human Ancestry

In QS 2:30, "khalifah" usually is translated as "successor." So that means there has to be other creature that used to Allah's vicegerent before Adam and his children. Moreover, the angels already knew about the creatures that might look like "humans" which were entrusted the khalifah role. The angels cannot comprehend this decision as the previous humans used to bring atrocities to the earth. Is this fact has something to do with the "evolution" phenomenon observed through archeological findings? #question