Were there other beings or "Humans" already on the earth when God created Adam and Eve. I ask because when Adam and Eve had children they had two sons, Cain and Able.

Cain killed Able and then Cain was banished and went to the wilderness where he found his wife and they had children. Where did his wife come from some might ask.

My thoughts on this have always been that if God created Adam in his image and Eve as a companion then there is a blood line from God there. Cains wife might have just been another human that God created along with the animals but the others were not created in his own image.

Either that or we are all inbreed incest descendants