Fig. 9: Schematic of microbial succession and biogeochemical processes in serpentinite mud at the Mariana forearc.
This schematic depicts lipid biomarker transitions from pelagic sediment communities to extremophiles adapted to high pH and redox conditions in serpentinite mud. The Mariana forearc biosphere is fueled by alkaline serpentinization fluids enriched in H2, CH4, DIC, and organic acids, sustaining specialized microbial communities. Lipid and stable carbon isotope data reveal a shift from relict methanogenic archaea, likely engaged in hydrogenotrophic methanogenesis, to a later ANME-SRB community mediating anaerobic oxidation of methane (AOM). Changes in substrate availability likely drove this transition. Distinct lipid signatures, including unsaturated diethers, acyclic GDGTs, and ether-based glycolipids, highlight adaptations to pH stress, phosphate limitation, and fluctuating redox conditions. The presence of in-situ branched GDGTs suggests previously uncharacterized bacterial communities persisting in these ultra-oligotrophic conditions. The Mariana forearc serpentinite biosphere, shaped by episodic fluid flow and substrate shifts, provides insights into deep-sea subsurface habitability. DIC = dissolved inorganic carbon, ANME anaerobic methanotrophic archaea, SRB sulfate-reducing bacteria, AOM anaerobic oxidation of methane, GDGT glycerol dialkyl glycerol tetraether.
This schematic depicts lipid biomarker transitions from pelagic sediment communities to extremophiles adapted to high pH and redox conditions in serpentinite mud. The Mariana forearc biosphere is fueled by alkaline serpentinization fluids enriched in H2, CH4, DIC, and organic acids, sustaining specialized microbial communities. Lipid and stable carbon isotope data reveal a shift from relict methanogenic archaea, likely engaged in hydrogenotrophic methanogenesis, to a later ANME-SRB community mediating anaerobic oxidation of methane (AOM). Changes in substrate availability likely drove this transition. Distinct lipid signatures, including unsaturated diethers, acyclic GDGTs, and ether-based glycolipids, highlight adaptations to pH stress, phosphate limitation, and fluctuating redox conditions. The presence of in-situ branched GDGTs suggests previously uncharacterized bacterial communities persisting in these ultra-oligotrophic conditions. The Mariana forearc serpentinite biosphere, shaped by episodic fluid flow and substrate shifts, provides insights into deep-sea subsurface habitability. DIC = dissolved inorganic carbon, ANME anaerobic methanotrophic archaea, SRB sulfate-reducing bacteria, AOM anaerobic oxidation of methane, GDGT glycerol dialkyl glycerol tetraether.
Fats provide clues to life at its limits in the deep sea
Researchers at MARUM – Bremen University’s Centre for Marine Environmental Sciences – have made a discovery, just published open access in the journal Communications Earth & Environment, which, properly understood, should make depressing reading for creationists.
They have found living organisms both on and within the ocean floor, surviving in conditions where normal life would be impossible. These microorganisms inhabit mud volcanoes with a pH of 14, metabolising hydrogen and carbon to form methane by drawing energy from minerals in the surrounding rock. In other words, they live entirely without oxygen and with almost no organic matter, synthesising all they need from inorganic sources.
Informed creationists will recognise that these organisms directly refute their frequent assertion that life cannot arise from non-life — because producing life from non-life is precisely what these microorganisms are doing.
This also contradicts the biblical claim that all living things were created for the benefit of humans, since there is no conceivable way these organisms could serve any human purpose. Of course, to be fair, the authors of the Bible were completely ignorant of microorganisms, deep-ocean mud volcanoes, and chemosynthetic metabolism. They could only attempt to explain the larger creatures that lived in the limited region around their homes in the Canaanite hills.
And, as any informed creationist should also understand, these are exactly the sort of extreme conditions that biologists believe may have fostered the emergence of the earliest living organisms during the origin of life on Earth — once again undermining any claim that abiogenesis is impossible.


































