[HN Gopher] A 'lost world' of early microbes thrived one billion...
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A 'lost world' of early microbes thrived one billion years ago
Author : gumby
Score : 84 points
Date : 2023-06-18 14:24 UTC (1 days ago)
(HTM) web link (science.anu.edu.au)
(TXT) w3m dump (science.anu.edu.au)
| mensetmanusman wrote:
| Maybe we should launch these types of microbes to other planets
| since we know is possible for it to lead to humans and
| McDonald's.
| borissk wrote:
| Maybe we're already launching them - getting rid of all the
| microbes in a complex machine, like a Mars rover is almost
| impossible (without destroying electronics and other vulnerable
| parts on board).
| [deleted]
| gilleain wrote:
| Other discussion: https://news.ycombinator.com/item?id=36238560
| AlbertCory wrote:
| Honest question, not a joke:
|
| We know that _deep_ underground, and in vents in the ocean floor,
| there is still some life. Is it possible there are some extreme
| environments on Earth where this ancient life is still going?
| enkid wrote:
| All life is equally ancient and the pressure of evolution has
| molded all life for equal amounts of time. (But not necessarily
| to equal extents as the ability to adapt is itself an
| evolutionary process.) What we may find is an ancient branch,
| with some features preserved we don't know about, but also some
| features adapted for the extreme environment.
| not_alexb wrote:
| This seems like such a huge reductive statement to make.
|
| Suppose: on some planet untouched by man, there was a species
| identical to a species on earth, would you say they share the
| same ancestor?
|
| Suppose: I generated an organism (that already exists)
| starting from raw chemistry, would that share the same
| ancestor as the one that already exists?
| sharpneli wrote:
| 1) Probability of that is so miniscule as to be
| nonexistent. I'd suspect foul play at that point. As in
| someone just transporting the animal there. You can't
| really get identical DNA on earth. It's to be expected that
| it would be even harder if there are no common ancestors.
| 2) Yes. In order to make that you need to basically fully
| understand the organism in question. All of it's properties
| are the same and product of the same evolutionary history
| by the virtue of you just looking at the existing creature
| and making an 1:1 copy
| dryrun wrote:
| Funnily enough, I have the opposite view: given the
| amount of stars and of earth like planets in the
| universe, probabilistically speaking there is bound to be
| a random chance where two instances of life have the same
| DNA without ever being in contact.
|
| Disclaimer: I'm bad at maths and good at dreaming.
| anonymouskimmer wrote:
| :D Yes, you are. :)
|
| The bare simplest genomes are viral genomes about 1000
| bases long. These can only operate in environments
| created by more complex genomes. But even taking them,
| the theoretical diversity in a genome 1000 bases long,
| using the 4 canonical nucleic acids, is 4^1000. The
| number of _atoms_ in the entire universe is around 10^80
| (https://educationblog.oup.com/secondary/maths/numbers-
| of-ato... ).
|
| There's a lot of complexity here: other life may use
| other nucleotides; those atoms and bases are constantly
| being rearranged; many base changes are relatively silent
| - they don't materially matter; etcetera.
|
| I don't know how to calculate all of the rest of these
| factors, but I think the odds are more than astronomical.
| borissk wrote:
| >> The number of atoms in the entire universe is around
| 10^80
|
| This is incorrect. It's an unsolved question in modern
| physics if the universe is finite or infinite. Even if
| it's finite most theoretical physicists believe that
| visible universe (94 billion light years across) is only
| a small piece of a far larger universe - so there are
| probably far more atoms.
|
| If the universe is infinite it may be that there are
| infinite number of copies of every living organism on
| Earth out there.
| anonymouskimmer wrote:
| At that point aren't we getting into the idea of a
| multiverse, and not a universe anymore? We have no non-
| hypothetical knowledge of what exists beyond the limits
| of the universe as it descended from what we can still
| see of the radiation shortly after the Big Bang. However,
| from that radiation, can't we get a ballpark figure for
| the atomic limits of the Big-Bang-Universe?
| borissk wrote:
| No, the different multiverse hypotheses are something
| different. The size of "our" universe is unknown, we can
| can see a sphere with a diameter of 94 billion light
| years. How much is there beyond that sphere is a research
| topic. No light from beyond the sphere has reached us
| during the lifetime of the universe.
| anonymouskimmer wrote:
| This is about inflation, right? We don't know how much
| the universe inflated after the big bang, just that it
| did.
| _Microft wrote:
| _> I don 't know how to calculate all of the rest of
| these factors, but I think the odds are more than
| astronomical._
|
| OK, let's do this then. Here we will approximate the
| ratio 4^1000/10^80:
|
| x = 4^1000 / 10^80
|
| ln(x) = 1000 * ln(4) - 80 * ln(10) // You know your
| logarithm calculation rules, right? Right?!
|
| ln(x) = 1386 - 184 // Who needs decimal places anyways?
| ;)
|
| ln(x) = 1202
|
| x = 10^522
| anonymouskimmer wrote:
| > You know your logarithm calculation rules, right?
| Right?!
|
| Eh, at one point I did. I'll take your word for it. It
| seems familiar.
|
| Now factor in number of rearrangements since the universe
| started. Or heck, let's keep it simple to the last 4.5
| billion years.
|
| I count about 30 atoms in a nucleotide, so X is a bit
| more than 10^523.
|
| Let's say 2 rearrangements per day (this will vary
| dramatically, but I have to pull some number out of a
| hat). Over 4.5 billion years that's on the order of a bit
| more than 10^12. so X is around 10^511.
|
| Yep, still more than astronomical.
| dryrun wrote:
| So you're telling me that there _is_ a chance! ;)
|
| And I'm very sad to (re?)learn this finite number of
| atoms in the universe, that's quite underwhelming for
| something expanding all the time.
| anonymouskimmer wrote:
| The number only seems small because we use notation to
| make it seem small.
|
| Most combinations of nucleotides aren't functional, or
| even capable of being synthesized by natural processes.
| This limits what can be created quite a bit. The true
| odds are still extremely high, but not nearly as high as
| these calculations guess.
| canadianfella wrote:
| [dead]
| not_alexb wrote:
| 1. Identical DNA is probably impossible in any case, even
| on earth, right?
|
| 2. Seems like you're broadly stretching the definition of
| a biological ancestor.
| enkid wrote:
| If it was truly identical, i.e. same anatomical and
| biological features, it would be proof that something had
| transported them there, and would therefore be a branch of
| life from Earth.
| not_alexb wrote:
| If it was truly an identical _species_ and it was the
| simplest form of life possible, you 're saying that it
| could only be transported from earth? That seems a bit
| shaky. You don't think the same factors that created the
| first lifeform on earth couldn't naturally be reproduced
| anywhere else to create that same lifeform?
| retrac wrote:
| Taking the premise rather literally, it would mean, for
| example, that the DNA of the organism would be typical
| for a member of its species on Earth. The odds of
| hundreds of millions of bits of genetic information
| coincidentally being the same are, if you'll pardon the
| expression, astronomical.
| Retric wrote:
| Astronomical is if anything understating how unlikely
| that would be.
| fikama wrote:
| it may not share common ancestor, but from your comment I
| assume it could reproduce with earth based counterpart.
| Thus it would be considered by the most popular definition
| to be the same species.
| AlbertCory wrote:
| The original question was about ancient life still existing
| on Earth, not hypotheticals.
| not_alexb wrote:
| And the answer gave such certainty to what ancient life
| would be like that my hypotheticals should be able to be
| answered (in the same context) with just as much
| certainty.
|
| It's trivial to apply my hypotheticals to models in which
| life didn't all descend from a common ancestor.
| _a_a_a_ wrote:
| > It's trivial to apply my hypotheticals to models in
| which life didn't all descend from a common ancestor
|
| We don't have such a thing to our knowledge so it's not
| trivial. If you still feel it is, do the application
| yourself - it's trivial after all.
| not_alexb wrote:
| I don't think you understand what I'm saying. You can
| arbitrarily create models of earth life that didn't have
| a common ancestor via "my" hypotheticals which are just
| as valid as univeral common ancestor (which predominantly
| features: there is something common in all life, so all
| life must have came from the same place; obviously this
| is a gross oversimplification but that's what we're
| dealing with in the answer)
| _a_a_a_ wrote:
| > You can arbitrarily create models of earth life that
| didn't have a common ancestor
|
| I'm finding it very difficult to understand what you mean
| by "models of life". Actually I have no idea. What does
| this phrase even mean?
| anonymouskimmer wrote:
| You're invoking god and magic (i.e. sufficiently
| implausible coincidence and sufficiently advanced
| technology). Yes, god and magic can render most
| descriptions of how the universe operates inadequate.
| not_alexb wrote:
| I am absolutely not. There are lines I didn't draw for
| the sake of time. Re: think about how you could translate
| my hypotheticals into how nature could do that on its own
| (obviously over a much longer course of time and
| fortuitous conditions).
| anonymouskimmer wrote:
| 1) I presumed that the person you originally replied to
| was speaking of terrestrial life when they wrote "all
| life".
|
| 2) There are thoughts that life on Earth, presuming it
| started on Earth and wasn't seeded from meteorites, may
| have started from multiple populations. But it's presumed
| that if it did so those multiple populations were either
| out-competed by one population, or sufficiently alike
| that they effectively merged in their descendants.
|
| At any rate, at this point, all life that we have so far
| detected shares similar enough features to presume a
| common origin. This includes incredibly separate lineages
| such as the bacteria and archaea.
|
| Would you consider modern computers to be descended from
| IBM mainframes? Someone building a duplicate lifeform
| from parts based on existing knowledge and existing
| lifeforms does not negate that those existing lifeforms
| evolved into form since the beginning of terrestrial
| life. Your work is standing on preexisting evolutionary
| knowledge, processes, and a chain of life, even if it
| technically replaces biological reproduction with a human
| engineer.
|
| From a dialectical point of view you're effectively
| invoking god to nitpick. If you believe you aren't you're
| going to have to spell it out for me.
| civilitty wrote:
| Yes, but it's relatively unlikely to go back a billion years
| given how geologically active our planet is and how fast
| microbes can mutate.
|
| The oldest I can think of are the Movile Cave [1] which was
| isolated for 5.5 million years before it was discovered and
| Lake Vostok [2] which has been isolated for tens of millions of
| years.
|
| [1] https://en.m.wikipedia.org/wiki/Movile_Cave
|
| [2] https://en.m.wikipedia.org/wiki/Lake_Vostok
| kulahan wrote:
| We already know there are some extreme environments with
| ancient life!
|
| The Movile cave [1] has been sealed off from the atmosphere for
| 5.5 million years, and it's filled with very unique creatures.
| They survive off of chemosynthesis, rather than photosynthesis.
| It's an extremely low-oxygen environment!
|
| [1]https://en.wikipedia.org/wiki/Movile_Cave
| zabzonk wrote:
| it's both possible and likely, depending on what you mean by
| extreme - doubt much is going on in the mantle or the core.
| AlbertCory wrote:
| True. About all we know for sure is what's in very deep
| mines, or at the bottom of the ocean. AFAIK.
| zabzonk wrote:
| also https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole
| gilleain wrote:
| I'm no expert, but my understanding is that past a certain
| point in history, the life that could thrive depended on an
| environment that no longer exists.
|
| For example, the Great_Oxidation_Event
| (https://en.wikipedia.org/wiki/Great_Oxidation_Event) that
| killed off many anerobic organisms. So there are still pockets
| environments that can support such anaerobes, but they are
| rare.
|
| Many Archaea (https://en.wikipedia.org/wiki/Archaea) are
| inhabitants of extreme environments - the extremophiles - but
| are they the same organisms as the ancient life here, or also
| relatives?
| ajross wrote:
| Seems like the real surprise here isn't the chemistry itself
| (which matches modern forms), it's that evidence for eukaryotic
| life from this era is scarce. Eukaryotes apparently hid for a
| billion years in an ecosystem completely dominated by prokaryote
| life. Which I guess is surprising since in theory they're
| supposed to be more complex and adaptable.
| andrewflnr wrote:
| I wonder if the "hiding" phase was pre-mitochondrial. We can
| get a long history of stem-eukaryotes (?), starting to build up
| these diagnostic chemicals, but they don't take over until
| mitochondria give them a bunch of energy.
| abecedarius wrote:
| What are the leading theories about why? The lower level of
| free oxygen?
| fbdab103 wrote:
| My naive thought - complexity kills all things. Eukaryotic
| cell is bigger, has more metabolic processes, can have
| specialized life cycle, etc. All of which means that it is
| slower growing and could be out-competed by the faster-
| growing, but less optimal organism. Natural selection only
| picks those who survived, not "the best".
| abecedarius wrote:
| Yes, that's roughly how I was thinking about more oxygen
| changing the game.
| asdff wrote:
| There were some moments in time that saw eukaryotes gain huge
| metabolic advantages:
| https://en.wikipedia.org/wiki/Symbiogenesis
| stackedinserter wrote:
| May I ask you to not touch it until we sort out the current
| problems?
| duckqlz wrote:
| "Professor Jochen Brocks inspecting the 1.6-billion-year-old
| rocks in Australia's Northern Territory. The rocks contained a
| primordial chemical structure that hinted at the existence of
| the Protosterol Biota."
|
| Not sure where this sentiment is coming from... Considering
| it's fat traces of a primordial species that is a common
| ancestor of all complex life on earth, which went extinct over
| 800 million years ago, and is found in ancient rocks around
| waterways literally all over the world; I think we are fine to
| touch it.
| jaapz wrote:
| It's a joke
| fsflover wrote:
| This is not Reddit, only most sophisticated jokes are
| accepted here.
| justinator wrote:
| Are you sure? I read here that Apple released a $3500 VR
| headset. I laughed pretty hard, but then realized the
| date.
| justinator wrote:
| Sorry, I forget that "play" is not very hn. It's very
| serious work, and one should take themselves _very_
| seriously.
| javajosh wrote:
| Finds like this are great because they can possibly shed light
| on the problem of abiogenesis. Many people, including myself,
| think there were possibly several generations of life that
| preceded the RNA/DNA driven stuff we have today. It was
| probably much simpler and simply consumed by later generations,
| and lost. If and when we send probes to water bearing places in
| our solar system, we may find these structures. This, in turn,
| will support the hypothesis that life is common in the
| universe. Which will, in turn, support the hypothesis that civs
| that can muster enough energy to expand beyond the initial star
| will instead use that power to destroy itself. Which will, in
| turn, help shape human civilization, if we choose to heed the
| warning.
| joeythedolphin wrote:
| Interesting. I depart towards one of your last steps. It's
| embarrassing to admit. But hundreds (or thousands) of these
| UFO reports are real and aliens have been visiting us since
| the beginning of human life. I said it. Please don't revoke
| my university degrees :) Actually, you can, they didn't
| really do anything for me anyway.
| zmix wrote:
| LOL, wanted to say the same: DO NOT TOUCH!
| gpvos wrote:
| Okay, apparently that is a reference to something I'm not
| getting. Could anyone please explain?
| acegopher wrote:
| Perhaps a reference to Australian health ministers asking
| fans not to touch soccer balls that go into the stands?
|
| https://www.theguardian.com/sport/2021/jun/02/do-not-
| touch-t...
| gonzo41 wrote:
| I'm not sure you know Austrlaia too well. Rio Tinto's probably
| laid explosives on in already and is ready to go!
| daniel_iversen wrote:
| Here's a non-paywall article about it from the actual University:
| https://science.anu.edu.au/news-events/news/scientists-disco....
| dang wrote:
| Ok, we changed to that from
| https://www.nature.com/articles/d41586-023-01847-8. Thanks!
| jessriedel wrote:
| > from the actual University
|
| In my experience, Nature News summaries are generally more
| trustworthy than university press releases. Nature News can
| suffer from hype problems seen in all scientific journalism,
| but it's one of the least bad sources. On the other hand,
| university press releases are basically unbound by journalism
| best practices; they can be almost pure marketing and should
| not be considered more authoritative just because they are
| associated with the university.
| onlypositive wrote:
| > non paywall
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