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I think possibly rare earth. There may be other life but unless it is on a planet with a tilted axis it will evolve to narrowly subsist in its own exact, unchanging band. Exploitation, which is the driver of all evolution on our planet, can only happen because there is exactly the correct degree of variability.
Life like ours may take 14-15 billion years to evolve on a more stable planet, and may not evolve at all on a less stable planet. We will probably find single cell organisms and simple life everywhere. We may not find intelligent life or advanced species yet.
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