More complex hydrocarbons are associated with carbon-based life forms (e.g. most of the stuff we use to make plastics come from crude oil which came from the de

More complex hydrocarbons are associated with carbon-based life forms (e.g. most of the stuff we use to make plastics come from crude oil which came from the decomposition of carbon-base lifeforms). IIRC, methane is one of the simplest hydrocarbons and thought to be naturally-occurring throughout the universe. Other complex hydrocarbons on the other hand...? (disclaimer: I might be wrong)