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gothlaw t1_iztjwqn wrote

I don’t know that it is “problematically early.” Life began spawning (or was successfully seeded by an rna universe) almost as soon as was possible given the solar system climate, conditions on Earth, and the sun settling into its calm adulthood — and appears to have done so on a few occasions.

It took a lot of evolutionary pressures and many bottlenecks and divergent paths to get from there to here, complex sapient life.

Is that cosmically early? Likely so. The universe could endure infinitely — and there will be potentially viable white dwarfs for hundreds of billions of years.

And it’s young now, relatively speaking. Just 13.6bn years old, with a lot of these third gen stars conducive to life being far younger than that — 4-5 billion years. Life on Earth started popping up just a few hundred million years after its formation.

Someone has to be first at the end of the day; it could be us. But I don’t see where that’s problematic, given the larger number of proponents who wonder why it hadn’t happened earlier; 13 bn years is “young” but still a long, long time.

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vroomfundel2 t1_izu36uv wrote

How does life appear to have arisen more than once? I thought we had evidence for just one tree of life.

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