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  randomImmigrant
  The metabolic science is really cool. The conclusion that life arose twice requires you to buy that proto-cells that grew on these vents and needed those metallic surfaces to survive didn’t count as “life”. Then, free living cells, bacteria and archea, could maybe be argued as having independent paths as they plugged the gaps in their metabolism independently. Same DNA/RNA, same proteins. Same broad rules of metabolism. Just some alternate paths through chemical space to plug in the metabolic gaps and get free from metal surfaces.To me, these are clearly not independent paths, but rather the branching of proto-life into two of the great kingdoms of life. It’s a stretch to call this two origins rather than a branching.Then a couple billion years later, one of em ate the other, and rather than destroy it, they both started a symbiotic relationship, and we were off to the eukaryotic race. This is all the same web of life. Not two independent streams.
• andrewflnr
  The headline is a little confusing. They're still talking about a "split" between bacteria and archaea, so even under this theory, the very roots of metabolism and (I'm guessing) genetic code etc still have a single origin.Anyway, it does provide a nice reason that bacterial and archaeal cell membranes are different.
• MarkusQ
  Clickbait headline.Should be "Life left mineral substrate at least twice" or some such. The research is interesting, but they're playing word games in the telling of it by saying the most recent common ancestor of all life wasn't alive (because it was dependent on a mineral surface), but two of it's children gave rise to lineages that were.
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  gyomu
  The link the site points to seems like a better source (no ads, cites DOI etc, affiliated with AAAS rather than random aggregator website):https://www.eurekalert.org/news-releases/1138775
• Rigdanir
  I find this fascinating. LUCA clearly predates some pretty core, basic metabolic capabilities, and yet nucleotide metabolism is complete. This seems to indicate that LUCA and its progenitors were confined to their hydrothermal vents and that the cells could not survive beyond due to the missing metabolic networks.I wonder if LUCA was not a single cell, but many different populations in different hydrothermal vents, exchanging genetic material wrapped by accident in the remains of the cell membranes as the host cells die and are ejected from their vents.Perhaps the missing post-LUCA metabolic enzymes evolved by accident from proteins recruited simply to concentrate the required metal ions that are scarcer and ever more diluted the farther from the black smokers you get. Free living was merely a happy bonus effect.
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  pingou
  If true, fl in the Drake equation just got much bigger.
• anon
  undefined
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  gyre007
  Major Seveneves vibes from this
• ChrisMarshallNY
  I was already under the impression that life on Earth has had several "Game Over -Play Again?" periods.I assume that the difference here, is that it went completely to zero, before restarting. The other times, there was a bit clinging on, that seeded the restart.
• victorbjorklund
  Sounds cool. Anyone with more knowledge that can say if this is really as proven as they suggest and if it is a big thing or not?
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  peter_stokes
  unfortunately the field of abiogenesis, just like extraterrestrial life, is a lost cause.The reality we will never be able to replicate creation of life nor find life on other planets (except via contamination). it's why we've never gotten any closer. and i'm not even religious
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  ck2
  what's really going to blow your mind is our solar system looked completely different several times with different proto-planets and Earth/Moon is likely made from remnants of those other planets* https://en.wikipedia.org/wiki/Formation_and_evolution_of_the...
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  NoMoreNicksLeft
  If life could arise once, why would the conditions not be amenable to it arising more than once? Sure, life tends to pollute-terraform for itself, but it's a big planet, with more than enough distance between the first occurrence and pristine environment for it to happen several more times.
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  qsera
  Origin of life on earth is not very interesting to me. Origin of life in the universe is where it is at...
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  theodorejb
  The idea that life came about by luck is completely absurd, even more so than thinking that a computer chip was created by chance erosion of a silicone wafer in exactly the right pattern.As I see it life was clearly designed by God.