[goodseedhomeschool (returned)]

A global flood could also cause a mass extinction. Maybe not so long ago. I guess the gas theory is as good as any theory that would try to find a reason other than biblical.

[DittoJed2]

They deal with that. See:

The mechanism also might explain other extinctions and climate perturbations (ice ages) and even the Biblical flood
And here I thought there was no evidence for a Biblical flood! Guess, all that gas rose to the top, produced condensation, and it rained sulphur water for 40 days and nights killing all the animals and people not on the ark. And here I thought they drowned. They just got gassed.