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Radical Study Suggests Life on Earth Arose Twice
- kazinator 2mo agoMy name is LUCA I'm your distant ancestooor I have some news for you Yes, they think life came once before
- pingou 2mo agoIf true, fl in the Drake equation just got much bigger.
- lanstin 2mo agoThey aren’t saying two totally different independent life creating event, they are saying that the earliest life depending on some external chemicals for parts of what is now covered by metabolism, and the tree of life diverged before those metabolic paths evolved inside the organism, so not totally the same emergence of life twice, but more stuff that reproduces and evolves but doesn’t meet modern standard for life.
- ch4s3 2mo agoThe science alert article should make this more clear, as its easy to get that impression.
- lanstin 2mo agoHonestly just more “biology has enormous areas without enough data that need filling in” causing previous generalizations (e.g. the central dogma of information flow being replaced by protein regulation of gene expression, non-coding DNA, even neurons and egg cells being produced thru life) to be overthrown, more than anything, IMO.
- PaulDavisThe1st 2mo agoI have absolutely no doubt that the next LLM/ML startup will be able to confidently, rapidly, productively and correctly fill in the missing data. Onward science!
- pingou 2mo agoYes I saw that, but the concept of "life" being quite blurry, I feel it still has an impact on the equation.
- mellosouls 2mo agoYep, now the probability of alien civilisations is completely unknown, but half the completely unknown it was before.
- theodorejb 2mo ago[flagged]
- victorbjorklund 2mo agoDo you reject evolution or do you believe God only created bacteria etc?
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- WelkinFolk 2mo agoI wish I were so vain as to think I'm so special, surely I could never have happened by chance.
- TacticalCoder 2mo ago> As I see it life was clearly designed by God. Which one? There are so many to choose from... And what created that God? I know it's turtles all the way down but still want to know.
- wildzzz 2mo agoThe dogma in many religions is that nothing created God or at least, there's no way to know. He exists outside our time and space. So from our perspective, God has always existed. If you believe that free will is true, then he can see all outcomes of the universe at once. If you don't believe in true free will, he sees the single timeline at once, from the big bang to the heat death of the universe. Personally, I don't believe in any religions. They were all developed before we had a much clearer idea of how our world works and there's just too much folklore mixed in with actual, yet primitive, philosophical discussions to abide by any of it. But like with the simulation theory, we have no way to know what exists outside our time and space so you shouldn't worry. If there is some bored extra dimensional teenager simulating our universe on their GPU, it ultimately doesn't matter because we'll never know.
- prewett 2mo ago
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- victorbjorklund 2mo agoSounds 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?
- peter_stokes 2mo agounfortunately 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
- Qem 2mo agoLikely we don't need to replicate. We just need to get a sample of life with completely independent origin to our kind of life here on Earth, to study. This way we would be able to separate what are universal properties for any life from historical contingencies specific to us. To have samples of a single kind of life complicates things.
- pfdietz 2mo agoWere that to happen it could be the worst news humanity ever receives, since it would greatly increase the chance the "Great Filter" is in front of us, not behind us.
- Qem 2mo agoNot if it's just microbial life. Anyway it's just one case or another. We knowing what's the case doesn't change it. If the news never break it would be just as bad, perhaps even slightly worse, as we would not have early warning to prepare.
- triceratops 2mo agoThe Great Filter is only one possible answer to the Fermi Paradox.
- 0xDEAFBEAD 2mo agoThe Milky Way is almost 14 billion years old. The Milky Way is perhaps 100K light-years in diameter. If you can travel at 0.1c you could colonize the Milky Way in perhaps around a million years, less than 0.01% of the age of the Milky Way. So, either there's a filter that's blocked interstellar colonization... or it has occurred already, and we just aren't aware of it (some sort of dark forest thing / we are being secretly watched by an extraterrestrial civilization). (This is a haunted galaxy either way!)
- gyomu 2mo agoThe 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 https://www.eurekalert.org/news-releases/1138775
- gilleain 2mo agoNice. This part was especially interesting: > “When we react phosphite, a form of phosphorus that naturally occurs in hydrothermal vents, with organic compounds, we get metabolic phosphorylation reactions overnight in water. Phosphite and palladium replace ATP and enzymes; it’s amazing, and it makes early evolution a lot easier to grasp” says Schlikker. As far as I know, there are no palladium enzymes ... checks ... ok, no _natural_ ones (that we know of). Which is interesting, as other enzymes in metabolism that use metals seem to have 'adopted' the metal(s) as a cofactor - like nickel, iron, molybdenum, even vanadium in at least one case.
- qsera 2mo agoOrigin of life on earth is not very interesting to me. Origin of life in the universe is where it is at...
- usrnm 2mo agoUntil we get any tangible proof of life outside Earth, there is no difference
- qsera 2mo agoActually I don't think there is life outside of Earth. I think we are truly alone in this universe.
- pfdietz 2mo agoI agree. The Fermi Argument, and the apparent rarity of K3 civilizations in other galaxies, is to me powerful evidence of the scarcity of life. At the least, this suggests SETI should focus on distant galaxies where the Fermi argument doesn't bite as much.
- VLM 2mo agoIts an exciting time to be alive because as of recently we certainly can detect planetary atmosphere major components out to at least 700 or so light years. https://en.wikipedia.org/wiki/WASP-39b https://en.wikipedia.org/wiki/WASP-39b There are astronomers actively working on minor component, more biologically interesting spectrographs like chlorophyll rather than spectrograms of carbon dioxide. That'll be harder to detect and limited to shorter ranges. At some point, probably very soon, like less than a decade, we'll be able to definitively state that we have atmospheric data in an onion layer shaped shell where we have unequivocable proof that out to X lightyears from Earth there's no planetary scale chlorophyll higher than a minimal level aka there's no earth-like plants on that planet. That shell will likely expand over time. Or, perhaps we will find a forested, or at least algae covered, planet, some light years away, which would be very interesting indeed. The question is rapidly changing from a purely philosophical belief to scientific observation, like right now, in real time, in the 2020s. What a cool time to be alive! This follows old, old stuff from radio astronomy along the lines of how far away could a 1960s radio telescope realistically detect life on earth. The answer IIRC was not very far LOL. But there's been a lot of progress in radio astronomy, etc. With respect to fermi filters etc people need to pay attention to how far away the Earth can be detected using radio telescopes. That distance has imploded since the end of analog UHF TV broadcasts. We still broadcast absolute swill, in fact more than ever, but digital detection range is much lower than analog AM carrier detection range from analog TV. The Earth has, to some extent, recently gone radio-quiet, which is interesting because we are still here, in fact more of us than ever. So WRT fermi filters of not being able to detect civilizations, disappearance of 1950s/1960s signals does not necessarily imply disappearance of civilization. Another example, if any aliens are watching the high altitude freon contamination of our atmosphere they're likely really confused right about now.
- andrewflnr 2mo agoThe 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 2mo agoClickbait 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.
- ck2 2mo agowhat'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_Solar_System#Terrestrial_planets https://en.wikipedia.org/wiki/Formation_and_evolution_of_the...
- pfdietz 2mo agoThe Youtube channel Kyplanet recently had an episode on recent arguments that the Earth/Moon system was formed from at least three giant impact events, not just a single one between proto-Earth and Thea that formed the current Earth and the Moon.
- randomImmigrant 2mo agoThe 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.
- ck2 2mo agothe Great Oxidation Event caused all kinds of crazy stress = crazy mutations/adaptations where one eventually started our path * https://en.wikipedia.org/wiki/Great_Oxidation_Event https://en.wikipedia.org/wiki/Great_Oxidation_Event one of my absolute favorite PBS Space Time on the subject * https://www.youtube.com/watch?v=abvzkSJEhKk https://www.youtube.com/watch?v=abvzkSJEhKk
- mycall 2mo agoYou would think there would be some isolated places where proto-life still exists for this to be true.
- Drakim 2mo agoHash competition from life might cause them to go extinct, and even if it happens again it just gets out-competed to extinction fast.
- giantrobot 2mo agoIt could be happening on my kitchen counter right this very second. But my kitchen counter, despite a recent cleaning, is absolutely lousy with microorganisms. So the new proto-life is immediately starved or more likely eaten by existing life. There's very few places on Earth that has not been colonized by some sort of life so there's very few places a new form of life could form and succeed long enough to itself grow and spread without being starved or eaten.
- ChrisMarshallNY 2mo agoI 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.
- gyre007 2mo agoMajor Seveneves vibes from this
- mttpgn 2mo agoBecause I had to look it up, a 2015 Neal Stephenson novel.
- NoMoreNicksLeft 2mo agoIf 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.
- jibal 2mo agobinaryturtle asked this question above and got about 10 responses. Conditions are very different, precursors to life get quickly consumed by existing life, origin of life is a rare event, etc.
- Rigdanir 2mo agoI 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.
- hamilyon2 2mo agoMany essential metabolic enzymes require metal ions for catalysis, structure, or substrate binding. So in some sense the dependence is still there, we just learned to take bits of substrate with us while travelling.
- merogran 2mo agoThe "life arose twice" makes for a sensational headline. Free-living cells arose twice would be more accurate. I heard a good way to describe LUCA is "half-alive", with about 40% of its metabolic reactions driven by the mineral substrates in the pores it lived in, and lacking a complete cell membrane. I can't help but speculate LUCA would have some simple membranes to cover the "windows" of the mineral pores and keep vital molecules inside - a tiny pore-dwelling metabolic network. The question of "how much independent metabolism counts as life" is looking a lot more like the question of "how many facial hairs make a beard"
- tim333 2mo agoLife may have arisen loads of times but life as we know it out competed the other forms. It's still a bit unknown how rare or common abiogenesis is. It'd be interesting to check out Mars more to see if there's any underground there.
- pasquinelli 2mo agothe article is about a study claiming that prokaryotes and eukaryotes emerged independently of each other. they're both still around, so "out competed" is a strange description.