Judaeo-Christian traditions give importance to Adam and Eve, and belief in them is seen in some quarters as being in opposition to evolution. Evolution is a theory which came from observations, and observations have been understood by evolution and both now enhanced by understanding genetics. Islam even quotes Adam and Eve being in the same location as the Hajj (it says something similar about Abraham too, like it needs to be in on the revelatory action). Yet the skull records now show several species of ape-people and early people stretching back millions of years. An analysis shows a complex branch structure and suggestions of up to 15 early human species existing at any one time.