According to the Bible all humans on Earth are descendants of Adam and Eve. Their children Cain and Seth create two separate lineages of human life on Earth. Cain and Seth would each have had sexual intercourse with one of their sisters (or nieces) to propagate humanity. Incest is normally a problem because of the likelihood of both parents passing on the same genetic defects to their offspring, but in this case the genetic defects would not have had time to occur, so would not have been a problem. | According to the Bible all humans on Earth are descendants of Adam and Eve. Their children Cain and Seth create two separate lineages of human life on Earth. Cain and Seth would each have had sexual intercourse with one of their sisters (or nieces) to propagate humanity. Incest is normally a problem because of the likelihood of both parents passing on the same genetic defects to their offspring, but in this case the genetic defects would not have had time to occur, so would not have been a problem. |