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by sanxiyn 1207 days ago
From Earth's hydrothermal vents, we know sunlight isn't necessary for life although energy is.
2 comments

We don’t know if life started in the light though and then migrated to the vents and adapted. My memory of it is that this is an unanswered question so far.
It's definitely an open question. But in his book "The Vital Question", Nick Lane makes an interesting case that they're actually the origin of all life: https://nick-lane.net/books/the-vital-question-why-is-life-t...
We know that life is older than photosynthesis. I'm not aware of another light-dependent metabolic process that could predate chemosynthesis.
Its a good hypothesis that life start at deep volcanic vents. Geologist Robert Hazen conducted lab experiments showing that all steps of the metabolic citric cycle occur in this environment without needing catalytic enzymes. Chemical reduction of magma provides the energy. As life developed enzymes to improve metabolism, it could migrate to colder, lower pressure environments.