Re: I think its probably more likely to be geological
It is interesting how we still rely on anthropocentric thinking.
Bill Ockham has nothing to say on the subject. Because, if you were to have as much knowledge of the Earth as we do of Mars, based on actual exploration, you could have landed in an awful lot of places which would lead you to conclude that any methane came from rocks.
But based on the evidence of our own planet, the "obvious" conclusion is that life seems to get everywhere. It's just that Aristotle was enormously influential, despite so many of his statements being so obviously wrong.