Noahs Ark and gene pools. Two by two is clearly silly, but what WOULD be the minimum number viable?

Question

To make a "spaceship ark" or a biosphere or the like to "save" all species from a global catastrophe, how many of each species would have to be preserved?

Answer 1

If I recall correctly, cheetahs are all descended from seven individuals in a recent bottleneck. There's some pretty serious lack of genetic diversity, but they're still surviving. But one can imagine a situation where seven individuals with unlimited resources would still be unable to propagate effectively - even one genetic disorder could prohibit the species from carrying on.

I think the number to have a fair chance of surviving is pretty small, especially if you were able to screen the members. If you're just picking at random, or you want a higher percentage chance of success, you'd have to go quite a bit higher.

Answer 2

There is no definite number; the more the merrier. The more members there are of a species, the more likely is genetic diversity that would preserve at least some members against a catastrophe. The ark story is, of course, fiction.

Answer 3

Ive always felt IF the story of Noahs ark is true, that there probably was more than one Noah.
There was no way on earth that Noah could have went all around the world in his lifetime and gathered up 2 of every creature on the planet. Penguins and Polar bears from the arctic? Pandas from China? Alligators from America? Kangaroos from Australia? No way.
Possibly there were hundreds of Noahs who built arks around the globe and loaded them with animals from their parts of the world.
Or maybe there was only one Noah, and he only took along alot of basic livestock that would be needed for his family to survive and continue on. Then God repopulated the rest of the earth with what animals were destroyed.
Or possibly it never happened at all and was just a myth.

Answer 4

I think there were a lot less species than there currently are. And I think that they had the ability to differentiate over the generations, which would account for the "common ancestors" in the geological column. Make sense? As in they didn't have to bring in a horse, donkey, and zebra. They were all one type before the flood. The Bible indicates the gene pool was clean enough for people to reproduce with family and suffer no ill effects. As sin progressed and that practice caused problems, God forbade it.

Answer 5

Good question... I've heard (sorry, no cite) if a population gets below about 30 there is *major doubt* as to viability. Hopefully someone below will have more (not even too sure how I'd Google that one.)

Answer 6

14 - 7pairs

Answer 7

4.7...but I really feel sorry for the .7 animal.