Without necessarily taking a position on this, I think those who insist on a a literal reading of Adam and Eve overlook the possibility that it is a mythological explanation for a more complicated reality, one that, like the reality of creation itself, was beyond the understanding of the Hebrews and, perhaps, still beyond us today, involving as it does not simply evolutionary biology but theology as well.
That is, the teaching on original sin and baptism can be true even if the story of Adam and Eve is a (perhaps gross) simplification of reality.