If life evolved from methane swamp gas, then why don't we fart methane like cows?

Um...actually we do

Try to eat only raw fresh vegetables for some time and tell me later what gas becomes your farts made of.😁

We ask all the tough Qs here on SW

Besides that, the methane swamp gas is a rather old proposed scenario for abiogenesis. There are better conjectures by now.

As long as we know, the only form of life that emerged from a swamp is Shrek.

But, of course, even if abiogenesis is not yet proved, the supernatural explanations aren´t much more trustable than cartoons.

Because they eat grass and we don’t

ASTTTT!!!