Comment No inbreeding depression prior to flood (Score 1) 548
Whom did Seth marry?
On the other hand, prior to a significant population bottleneck in the 17th century after creation of humankind, there weren't enough built-up deleterious mutations in the human genome to cause noticeable inbreeding depression. I guess that's why the commandment against incest didn't come until Leviticus nearly a millennium after the flood.