In a pure biological way, the bible has a problem anyways, since they define them as 'the first humans'.
The transition from asexual to sexual reproduction is what counts here, that transition has taken place way way way earlier than when the human species evolved into the ape-like creatures 'we' once were. It's questionable wether asexual reproduction (hermaphrodites) actually commit acts of incest (lol take snails as an example) , still when Adam and Eve (and Lilith lol) were just like us, then this probably wouldn't be relevant at all since they already were reproducing non-asexual for probably millions of years (you know, the pre-human species).

Cheers