10 ms·

Life on Earth may have begun 300M years earlier than previously thought

89 points by wrongc0ntinent 11y ago

6502nerdface 11y ago
> If confirmed, the discovery means life emerged a remarkably short time after the Earth was formed... So at what point does the lag time between accretion and first evidence of life become too short for "native" abiogenesis to be plausible, pointing toward a transfer scenario instead?
- hawkice 11y ago
  Honestly, that might be a different order of magnitude when it comes to speed -- maybe if we have evidence of life within the first ~10,000 years instead of hundreds of millions. We've only been trying to replicate the origin of life for couple hundred years, tops, at an extremely small percentage of locations on earth where we'd notice if it happened. It might be extremely likely to happen when you try everywhere on earth for hundreds of thousands of years, and that's a rounding error compared to dates we are looking at. A much better source for what you are talking about would be e.g. finding tardigrades or similar in the asteroid belt. That would show that life was part of the mix that went into the forming of the planets.
  - 6502nerdface 11y ago
    Yeah, I suppose once we've identified an actual mechanism or two of abiogenesis, we'll be in a better position to estimate expected wait times in likely environments. And if the wait times are as fast as you suggest, it simply may not be possible to date rocks/minerals accurately enough for the necessary comparison.
  - sunstone 11y ago
    On the other hand, if life creating was so relatively easy it would be much more likely to find evidence for multiple independent instances of life starting on earth. My understanding is that, so far, all life on earth is part 'one web' not multiple webs.
    - hawkice 11y ago
      tl;dr It's very likely that first-life creates a lock-out, quickly soaking up all resources that could be used for independent abiogenesis. Let's say the probability of new life is roughly constant (and a relatively low probability). It should roughly follow a Poisson distribution -- in other words, using current knowledge, and assuming (1) life would be created noticeably differently given similar circumstances and (2) it didn't (molecule chirality indicates both of these, for instance) AND (3) the events are independent, which you need for the distribution -- then it'd be pretty weird for something following a Poisson distribution where: Earth Exists: Time 0. We have physical things from the time period: Time 2 Event in the distribution: Life: Time 4 Then absolutely no new instances until time 45 (unit here is 100MM years) This is all by means of formalizing your argument, which is largely correct. But it's important to note that it assumes that the events are independent, which I strongly, strongly suspect they are not. Life takes resources and uses them up, and will expand until it meets carrying capacity. So first-past-the-post-wins seems like a much better guess as to the relationship between origins-of-life.
- Dylan16807 11y ago
  As far as I understand, the idea is that friendly conditions to life could turn into life in the geological blink of an eye, so there isn't such a point.
  - justinator 11y ago
    Another idea is those friendly conditions only seem to have occurred once here on Earth - everything living is descended from that one Thing. That's the kind of train of thought that keeps me up at night.
    - pluma 11y ago
      At astronomical timescales even Earth's life is just a blink of an eye. It's not at all unlikely that life on other planets happened, is happening or will happen somewhere out there. The odds are just pretty good that we'll never be able to find out because we not only happen to be in the wrong place to observe it, but also in the wrong time. That's pretty depressing IMO.
      - eru 11y ago
        > At astronomical timescales even Earth's life is just a blink of an eye. Age of the universe: ~13.8 billion years Life on earth: ~4.1 billion years That's a decent chunk, not the blink of an eye.
        codeshaman 11y ago
        > Age of the universe: ~13.8 billion years If the age of the Universe is 13.8 billion years, I wonder, what was happening 13.9 billion years ago? What about 13.8^2 = 190 billion years ago and even before that ? Kind of mind bending, but time seems to be infinite (at least to us) so at that scale, the life of Earth is really a blink of an eye or less.
        Sharlin 11y ago
        As far as we know, time began 13.8 billion years ago. Talking about events before that is not meaningful.
- hugh4 11y ago
  Never, really. When you've got ten to the forty something atoms jiggling up against each other on picosecond timescales, the difference between a rare event happening every million years and one that happens every billion years is pretty small.
- amelius 11y ago
  I guess that point will be reached at a timescale when life can be bootstrapped in a lab.
amelius 11y ago
It really makes me wonder if life started multiple times independently. I guess certain molecules essential to life are right or left-handed, and if life started several times independently, we should (statistically) see both types of handedness. So then the question is: why didn't life start multiple times independently?
- warfangle 11y ago
  I guess if certain particles essential to matter as we know it are either particles or anti-particles, and if matter coalesced several times independently, we should see both types of matter ;) The main difference between particles/antiparticles and chirality, though, is life tends to extinguish other life in its competition for replication. Antiparticles just tend to annihilate 1:1.

> If confirmed, the discovery means life emerged a remarkably short time after the Earth was formed... So at what point does the lag time between accretion and first evidence of life become too short for "native" abiogenesis to be plausible, pointing toward a transfer scenario instead?

hawkice 11y ago
Honestly, that might be a different order of magnitude when it comes to speed -- maybe if we have evidence of life within the first ~10,000 years instead of hundreds of millions. We've only been trying to replicate the origin of life for couple hundred years, tops, at an extremely small percentage of locations on earth where we'd notice if it happened. It might be extremely likely to happen when you try everywhere on earth for hundreds of thousands of years, and that's a rounding error compared to dates we are looking at. A much better source for what you are talking about would be e.g. finding tardigrades or similar in the asteroid belt. That would show that life was part of the mix that went into the forming of the planets.
- 6502nerdface 11y ago
  Yeah, I suppose once we've identified an actual mechanism or two of abiogenesis, we'll be in a better position to estimate expected wait times in likely environments. And if the wait times are as fast as you suggest, it simply may not be possible to date rocks/minerals accurately enough for the necessary comparison.
- sunstone 11y ago
  On the other hand, if life creating was so relatively easy it would be much more likely to find evidence for multiple independent instances of life starting on earth. My understanding is that, so far, all life on earth is part 'one web' not multiple webs.
  - hawkice 11y ago
    tl;dr It's very likely that first-life creates a lock-out, quickly soaking up all resources that could be used for independent abiogenesis. Let's say the probability of new life is roughly constant (and a relatively low probability). It should roughly follow a Poisson distribution -- in other words, using current knowledge, and assuming (1) life would be created noticeably differently given similar circumstances and (2) it didn't (molecule chirality indicates both of these, for instance) AND (3) the events are independent, which you need for the distribution -- then it'd be pretty weird for something following a Poisson distribution where: Earth Exists: Time 0. We have physical things from the time period: Time 2 Event in the distribution: Life: Time 4 Then absolutely no new instances until time 45 (unit here is 100MM years) This is all by means of formalizing your argument, which is largely correct. But it's important to note that it assumes that the events are independent, which I strongly, strongly suspect they are not. Life takes resources and uses them up, and will expand until it meets carrying capacity. So first-past-the-post-wins seems like a much better guess as to the relationship between origins-of-life.
Dylan16807 11y ago
As far as I understand, the idea is that friendly conditions to life could turn into life in the geological blink of an eye, so there isn't such a point.
- justinator 11y ago
  Another idea is those friendly conditions only seem to have occurred once here on Earth - everything living is descended from that one Thing. That's the kind of train of thought that keeps me up at night.
  - pluma 11y ago
    At astronomical timescales even Earth's life is just a blink of an eye. It's not at all unlikely that life on other planets happened, is happening or will happen somewhere out there. The odds are just pretty good that we'll never be able to find out because we not only happen to be in the wrong place to observe it, but also in the wrong time. That's pretty depressing IMO.
    - eru 11y ago
      > At astronomical timescales even Earth's life is just a blink of an eye. Age of the universe: ~13.8 billion years Life on earth: ~4.1 billion years That's a decent chunk, not the blink of an eye.
      - codeshaman 11y ago
        > Age of the universe: ~13.8 billion years If the age of the Universe is 13.8 billion years, I wonder, what was happening 13.9 billion years ago? What about 13.8^2 = 190 billion years ago and even before that ? Kind of mind bending, but time seems to be infinite (at least to us) so at that scale, the life of Earth is really a blink of an eye or less.
        Sharlin 11y ago
        As far as we know, time began 13.8 billion years ago. Talking about events before that is not meaningful.
hugh4 11y ago
Never, really. When you've got ten to the forty something atoms jiggling up against each other on picosecond timescales, the difference between a rare event happening every million years and one that happens every billion years is pretty small.
amelius 11y ago
I guess that point will be reached at a timescale when life can be bootstrapped in a lab.

amelius 11y ago

It really makes me wonder if life started multiple times independently. I guess certain molecules essential to life are right or left-handed, and if life started several times independently, we should (statistically) see both types of handedness. So then the question is: why didn't life start multiple times independently?

warfangle 11y ago
I guess if certain particles essential to matter as we know it are either particles or anti-particles, and if matter coalesced several times independently, we should see both types of matter ;) The main difference between particles/antiparticles and chirality, though, is life tends to extinguish other life in its competition for replication. Antiparticles just tend to annihilate 1:1.