Actually, the folks studying species extinction say that about 8 pairs are required for any species to survive. For example they brought back the Condor with a dozen or so individuals.
I'm not sure why this is necessary, but I assume to prevent harmful mutations from becoming the norm. Like the old saw about not marrying your sister.
This is one of the problems with the story of Noah. Saving two of every species just wouldn't work.
Thanks. For now I am just trying to understand the positions taken by evolutionists without any Bible appealations as there is no basis for agreement there. But the fact is that of the clean beasts and birds they were seven and seven male and female. Of the unclean just male and female. And God brought the animals to Noah, not as some suggest that Noah had to round them up. For most folks, their God is too small. I suspect there is a lot of subjectivity at work on both sides of this issue. Regards.