
Fossil Discoveries Challenge Ideas About Earth’s Start - IntronExon
https://www.quantamagazine.org/fossil-discoveries-challenge-ideas-about-earths-start-20180122/
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hyperpallium
Even if there was heavy bombardment, it wouldn't be everywhere at once, and
deep sea vents would be somewhat protected by kilometers of water. (assuming
the bombardment wasn't so severe as to vapourise the ocean).

That life was present as soon as earth was hospitable fits with the intriguing
theory that extrapolates the origin of life to _predate_ earth, based on the
rate of increase in complexity: [http://www.davidyerle.com/where-are-the-
aliens/](http://www.davidyerle.com/where-are-the-aliens/) (actual article pdf
287kb: [https://arxiv.org/pdf/1304.3381](https://arxiv.org/pdf/1304.3381))

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md224
Umm... that’s a pretty remarkable finding... how is this the first time I’m
hearing about this? Is their evidence considered too weak or speculative to
challenge the currently accepted timeline? I thought we had this whole
evolution thing (mostly) figured out...

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IntronExon
Panspermia as a theory has been around for a while, but there’s no real
evidence to support it yet. The weaker forms of the theory don’t postulste
life as being extraterrestrial, but the complex organic building blocks of
life could be.

Until a rigorous model of life can be developed, until life can be created in
vitro from non-living stuff, or until evidence of life or complex organics can
be found beyond Earth it’s hard to prove or disprove.

The same can be said of pretty much all theories concerning the origin of life
on Earth though.

[https://en.m.wikipedia.org/wiki/Panspermia](https://en.m.wikipedia.org/wiki/Panspermia)

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samplatt
The ending of Clarke's Light of Other Days involves a motif that's common to
his work - a civilisation of small, chitinous creatures that existed prior to
the accepted cooling-and-then-life-arises theory. How awesome would it be if
it turned out to be right.

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Florin_Andrei
I'm a big fan of ACC, but the "common motif" doesn't ring a bell. Could you
provide more examples where this occurs in his work?

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sharemywin
Not to say that's what happened, but I wonder how far we are from being able
to seed a planet with life? and what it would cost?

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Unkechaug
A better question might be "should we?" Consider that we as a species seem
incapable of taking care of ourselves on our own planet. Unless that changes,
it seems pretty irresponsible. We would be like the dad that skipped town.

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wybiral
We wouldn't have to take care of it. Could just seed and let life do its
thing.

But to me the real "should we?" is because it might destroy evidence of other
events. Maybe there are simple organisms hiding somewhere or some poorly
understood phenomenon that would be obscured or destroyed by our introduction
of life.

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IntronExon
I’d tend to agree, from a sort of “Prime Directive” direction. We’re not so
good at guessing really global, long term consequences in unfamiliar systems.
We would have to be so sure before introducing life on a distant world. What
if there was already very simple life just getting started? We could reduce
universal biodiversity with the best of intentions.

