Non-oxygenic photosynthesis (anoxic photosynthesis) uses photons at longer wavelengths to split molecules such as hydrogen sulphides rather than water, and is far more suited to the light from red dwarfs.
So life on Trappist-1? Likely no Great Oxidation Event, but instead anoxygen photosynthetic bacteria would dominate over oxygen-producing cyanobacteria. Without oxygen, complex animal life may not exist! -- William Welsh at #IAU2024 #Astronomy2024
@elizabethtasker
No complex life without oxygen?
<Loricifera has entered the chat>
@elizabethtasker @mike_malaska Oh sure, *you* try living in an anoxic lightless environment!
(No, I guess they’re not going to produce a star-faring civilization. But it’s still pretty cool!)
@mike_malaska @elizabethtasker That’s really cool! I’d love to know if they still have mitochondria.
But with all extremophiles I would think the real question relevant to exolife is not whether they can *survive* in that environment, but whether they *arose* there to begin with. Humans can now live in all sorts of environments that we could never have arisen in initially.
@elizabethtasker @michaelgemar
Yeah. I've no clue on orgin of life. (Maybe hydrothermal pocket? Maybe warm little pond, maybe deep ice pocket? Maybe delivered from somewhere else?)
But energy to maintain and grow a multicellular thing (even tiny) seems to not absolutely require high-energy oxygen.
So, by analogy, maybe a red dwarf illuminated thing can also be tiny multicellular?
Elizabeth Tasker
Michael Gemar
Mike Malaska