4 ms·

For all we know, life started on Mars, not here. Hence the "sudden explosion" of life.

vlovich123 1y ago
I prefer the theory that life is the natural evolution of physical chemical processes given certain conditions. That explains why we think that we’re likely to find life on Neptune. Otherwise it begs the question of why did life start on Mars, and that’s a turtles all the way down kind of situation.
- lawlessone 1y ago
  neptune?
  - vlovich123 1y ago
    Sorry, I meant a moon of Neptune (Triton). There's also a recent research study suggesting Titan also has life.
- roncesvalles 1y ago
  In addition to one seeding the other, neighboring planets having life also gives support to extra-solar-system panspermia. An advanced civilization could've fired off the "seed" in some vehicles on calculated trajectories to all viable planets, and the Solar System happened to be within the radius of their efforts.
  - estimator7292 1y ago
    Panspermia is such a juvenile take. It doesn't answer the question at all, just hand-waves it all away with a "because I said so". It's like a religion.
    - roncesvalles 1y ago
      I was never attempting to answer where life came from. It's simply that if Mars and Earth both have/had life, the probability that they came from some common cosmic seeding project in our neighborhood becomes a bit more likely.
      - vlovich123 1y ago
        Vs it’s a natural inevitable process when the conditions support it?
  - vlovich123 1y ago
    Where do the turtles start?
- d1sxeyes 1y ago
  If that is true, then why does it seem that there has been only a single origin event on Earth?
  - rrmm 1y ago
    Does it seem that way? It happened at least once (but could have happened many times without "taking over"), and certainly one sort of life seemed to successfully out-compete all others. But none of that says single-origin to me. Early on I would expect a whole lot of "horizontal gene transfer" sort of things to have taken place. So for example in addition to actual horizontal gene transfer, there are mechanisms like one organism enveloping another to eventually become organelles, co-opting products from each other, etc. All of which would act to homogenize life and make certain process ubiquitous. Finally, there's an outside chance that "there's only one way to do it".
    - roncesvalles 1y ago
      I think single origin event is highly likely because, for example, it's wholly conceivable that a slightly different variant of AUCG (or just one of the molecules) could've emerged and it would have similar characteristics, but not differentiated enough that one would have a very strong selective advantage over the other. Diversity could exist in harmony and the lack of any diversity is a pretty strong signal that the only extant version is either very rare or the only to ever emerge. Everything in nature is diverse except RNA/DNA and this fact alone is a sort of evidence.
      - vlovich123 1y ago
        Or the basic life that forms is going to look the same regardless of where it starts on Earth, meaning that you’d never have evidence of two origins. Or RNA was just a winning virus that infected all other life or killed all competition to make it seem like there was only one origin. Absence of evidence is not evidence of absence.
        roncesvalles 1y ago
- aurareturn 1y ago
  "You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant." -Jeremy England Life increases entropy and doesn't break 2nd law of thermodynamics.
  - mr_mitm 1y ago
    Actually it's enough to have a sufficiently large amount of hydrogen. No extra light necessary.
- deleted 1y ago
  [deleted]
elevaet 1y ago
They keep pushing back the date of the LUCA - I think it's meant to be 4.2 billion years ago now, a time when Mars was more nurturing than it is now, maybe moreso than Earth at the time? I hope we find out it started on Mars and jumped to Earth, how cool would that be?
soiltype 1y ago
I don't think there's any reasonable way to call that a likely scenario though. If life did emerge on Mars, why wouldn't it also emerge on Earth? For both planets to have life, the most likely explanation is that it's just common.

I prefer the theory that life is the natural evolution of physical chemical processes given certain conditions. That explains why we think that we’re likely to find life on Neptune. Otherwise it begs the question of why did life start on Mars, and that’s a turtles all the way down kind of situation.

lawlessone 1y ago
neptune?
- vlovich123 1y ago
  Sorry, I meant a moon of Neptune (Triton). There's also a recent research study suggesting Titan also has life.
roncesvalles 1y ago
In addition to one seeding the other, neighboring planets having life also gives support to extra-solar-system panspermia. An advanced civilization could've fired off the "seed" in some vehicles on calculated trajectories to all viable planets, and the Solar System happened to be within the radius of their efforts.
- estimator7292 1y ago
  Panspermia is such a juvenile take. It doesn't answer the question at all, just hand-waves it all away with a "because I said so". It's like a religion.
  - roncesvalles 1y ago
    I was never attempting to answer where life came from. It's simply that if Mars and Earth both have/had life, the probability that they came from some common cosmic seeding project in our neighborhood becomes a bit more likely.
    - vlovich123 1y ago
      Vs it’s a natural inevitable process when the conditions support it?
- vlovich123 1y ago
  Where do the turtles start?
d1sxeyes 1y ago
If that is true, then why does it seem that there has been only a single origin event on Earth?
- rrmm 1y ago
  Does it seem that way? It happened at least once (but could have happened many times without "taking over"), and certainly one sort of life seemed to successfully out-compete all others. But none of that says single-origin to me. Early on I would expect a whole lot of "horizontal gene transfer" sort of things to have taken place. So for example in addition to actual horizontal gene transfer, there are mechanisms like one organism enveloping another to eventually become organelles, co-opting products from each other, etc. All of which would act to homogenize life and make certain process ubiquitous. Finally, there's an outside chance that "there's only one way to do it".
  - roncesvalles 1y ago
    I think single origin event is highly likely because, for example, it's wholly conceivable that a slightly different variant of AUCG (or just one of the molecules) could've emerged and it would have similar characteristics, but not differentiated enough that one would have a very strong selective advantage over the other. Diversity could exist in harmony and the lack of any diversity is a pretty strong signal that the only extant version is either very rare or the only to ever emerge. Everything in nature is diverse except RNA/DNA and this fact alone is a sort of evidence.
    - vlovich123 1y ago
      Or the basic life that forms is going to look the same regardless of where it starts on Earth, meaning that you’d never have evidence of two origins. Or RNA was just a winning virus that infected all other life or killed all competition to make it seem like there was only one origin. Absence of evidence is not evidence of absence.
      - roncesvalles 1y ago
aurareturn 1y ago
"You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant." -Jeremy England Life increases entropy and doesn't break 2nd law of thermodynamics.
- mr_mitm 1y ago
  Actually it's enough to have a sufficiently large amount of hydrogen. No extra light necessary.
deleted 1y ago
[deleted]

elevaet 1y ago

They keep pushing back the date of the LUCA - I think it's meant to be 4.2 billion years ago now, a time when Mars was more nurturing than it is now, maybe moreso than Earth at the time? I hope we find out it started on Mars and jumped to Earth, how cool would that be?

soiltype 1y ago

I don't think there's any reasonable way to call that a likely scenario though. If life did emerge on Mars, why wouldn't it also emerge on Earth? For both planets to have life, the most likely explanation is that it's just common.