That leaves us with the final barefaced option. The apparent paradox is not a paradox at all: LUCA really was chemiosmotic, with an ATP synthase, but really did not have a modern membrane, or any of the large respiratory complexes that modern cells use to pump protons. She really did have DNA, and the universal genetic code, transcription, translation and ribosomes, but really had not evolved a modern method of DNA replication. This strange phantom cell makes no sense in an open ocean, but begins to add up when considered in the environment of alkaline hydrothermal vents discussed in the
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