Konstantine said: "In each one of your religious minds there must be a certain amount of doubt that we populated the planet from adam and eve.
If this were true Jesus would be condoning incest."
Incest would not have been a problem with Adam and Eve. For man was not created with any genetic defect. He was not yet fallen. Man's fallen state became the reason why incest became taboo.
Men were yet genetically very strong for hundreds of years after the fall. Men were yet living for hundreds of years, for the genetic decline was not a rapid process. Over time when man's decline finally reached a certain level, then the command against incest was given. Man did not know about DNA.
God understood genetics while man did not. Man was not yet capable of understanding such scientific knowledge. So, God simply gave a command prohibiting what we call incest.The prohibition was to prevent mankind from entering into a spiraling rapid self destruct mode genetically.
Today we accept incest as a wrong. In the beginning it was not the case.