There were 8: Noah, his wife, their three sons (Shem, Ham, and Japheth), and their three wives. If so, there must have been a whole of inbreeding in later generations.
Aside: The biblical story of the Ark and the flood in ripped off wholesale from Sumerian and Akkadian narratives.
Aside: The biblical story of the Ark and the flood in ripped off wholesale from Sumerian and Akkadian narratives.