Another problem with the Adam & Eve origin story involves the matter of ensoulment. For if there were an original Mom and Dad into whom God infused human souls, the Genesis story can work, even if it's interpreted as having taken place over a period of millions of years.
But any sort of polygenetic account raises a problem. Because, even assuming a severe human bottleneck in the late pliestocene, there still would have been at least several thousand surviving individuals, and that raises the question: Did God ensoul all of them simultaneously? Mitochondrial DNA evidence suggests that that must have been the case. But that would seem absurd, and in any case is not suggested anywhere in scripture nor later doctrine.