Does genetics & evolution undermine the Adam and Eve story? But then, don't we have a common ancestor.?

It's completely impossible isn't it? Because the inbreeding would cause all offspring to be infertile/unviable within a few generations? But then, all humans MUST have a common ancestor, stemming from the first male/female primates to evolve into humans, surely? (Or when a new species evolves, do thousands of new organissm aquire the mutations to survive the new environment, and thus there is such variety.)