How a Radical New View of Life Could Reveal Its Origin — And Aliens

A New Scientist feature on Assembly Theory, the framework developed by ASU astrobiologist Sara Imari Walker and Glasgow chemist Lee Cronin (Nature, 2023; Walker's 2024 book Life as No One Knows It). The theory asks not what life is made of but how complex an object's assembly history must be before it can only have been produced by life. Two quantities — assembly index and copy number — let researchers detect biology even where the chemistry is unrecognisable, making it a candidate framework for both the origin-of-life problem and the search for genuinely alien biospheres. Note: New Scientist blocked.