
Organic molecules discovered by Curiosity consistent with early life on Mars - lelf
https://phys.org/news/2020-03-molecules-curiosity-rover-early-life.html
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oarla
The article touches on this a bit, but I've always wondered what is defined as
life. As noted in this article, source of complex organic compounds on Earth
is most likely biological, but on other planets, the odds are pretty low for
that. If life is self sustaining complex organics, then I guess the bar is
pretty low to find it in the universe.

However, if life is defined as adapting complex organics(evolution), where the
errors in replication of cells triggers different combinations then it gets
more interesting as that is in a nutshell how life started evolving on Earth.

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briga
In biology 101, they taught us that life is something with the following
properties:

1\. Has order

2\. Has metabolism

3\. Has evolutionary adaptation

4\. Responds to the environment

5\. Reproduces

6\. Grows and develops

Which seems fine as a definition, but certain physical processes are still a
little ambiguous. Like consciousness, there's probably not a clear dividing
line between life and non-life, but rather a gradient between the two.

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bobbylarrybobby
Why is evolutionary adaptation a necessity? If some reasonably complex
organism evolved and then perfected its DNA replication to the point where no
mutations occurred, and thus it could not evolve any further, it would cease
to be considered alive?

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briga
Just because no mutations are occuring doesn't mean natural selection isn't
taking place, it just means that there are no fitter variants in that
organism's immediate fitness landscape

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wpasc
If we find life a second time in our solar system, would that imply that life
throughout the universe is much more likely to be abudant? Answers to the
fermi paradox I've heard is that there may be some unknown true difficulty for
creating life. A second form of life in our solar system would counteract that
belief?

If true, then I'd be worried about some Great Filter ahead of us (ie
technology destroying us) as that may be a plausible reason why we haven't
spotted aliens yet?

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aaronharnly
I suspect that intelligent-like-us life is vanishingly rare. It’s only
happened to one species (maybe a few of our extinct relatives) out of billions
of species on Earth so far. And even we spent most of our history not being
space-faring — it doesn’t feel inevitable even given our biology that we would
be.

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leetcrew
idle speculation: maybe there's an uncanny valley type effect where
intelligent tool users are inherently hostile towards their near peer species?
could explain why our ancestors are extinct but much less capable primates
still exist.

if true, the number of such species might converge to one over time.

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allovernow
Well, predisposition to tribalism may be the manifestation of a strong
evolutionary pressure against those early hominids who did not eliminate other
subspecies with prejudice.

