There are ideas that a pre-Adamic group of humans existed before Adam and Eve. A lot of this may be an attempt to reconcile scripture with naturalism. Some of it is driven by a misunderstanding of the Torah’s laws on sexual relationships, specifically “incestuous” ones. Unfortunately, some have taken this concept to the extreme and suggest that only those of certain ethnic heritage are actual humans from Adam and Eve; meanwhile, other people groups are sub-human because they don’t come from Adam and Eve. This sounds like a syncretism with Darwinism being used to devalue some people as animals while others are seen as children of God.