[beaver fever]

The present science concerning gas hydrate methane is that it is produced by biological organisms that decay from continental effluent and dead micro organisms at a depth of 300 to 600 meters on the continental horizons.

What ever happened on Titan is a different matter and may also be the result of now extinct biological processes or the result of purely geological processes. We just don't know.

That's what is exiting about science. You don't know until you know.

[JasonC]

We know a lot more than that. There is no life on Titan, nor any evidence or plausibility of any in the past. Methane is being produced in planetary quantities by geological processes without the presence of life. (We've also found metal catalysts that quite plausibly explain how that may happen). Meanwhile, here, we have never seen proven or probably reserves decline, since we started using oil. There is no theoretical reason to believe hydrocarbons are exclusively produced biotically, and there is no empirical reason to believe it is actually running out.