3 ms·

Is it possible for life in Vostok to be genealogically isolated from life elsewhere on Earth, so that life evolved from nothing multiple times?

tdyo 14y ago
I suppose it's possible, but the fact that it is, in fact, DNA is enough to suggest it's from the last universal common ancestor (LUCA). If it shares the same ultra-conserved ribosomal etc sequences, then it's even more likely from LUCA.
jlgreco 14y ago
I believe the estimates for how long Lake Vostok water has been isolated cap out at around 25 million years. Although that is an incredibly long time, it isn't anywhere close to long ago enough to ensure a sterile condition when it was first isolated (It would need to be several billion years to proceed life as we know it already blanketing the planet). As I understand it, the prevailing notion is that abiogenesis happened only a single time, or at least only a single time that stuck. The life that already exists does a pretty good job of ensuring that any primitive re-developed life never has a chance to actually get started. You would need to completely sterilize the environment to have a shot at witnessing abiogenesis again. Maaaybe all life in the lake died, rendering it sterile, and then new life formed, but that seems super unlikely to me. Why would the existing life die if there was enough nutrients/energy to allow new life to form? (Also, 25 million years is probably far too short of a timeframe to see abiogenisis bootstrap DNA based life)
- jbert 14y ago
  Agree with that, but would also like to throw in a scenario where there wasn't a sterile environment, but conditions were harsh enough for all present life to die, leaving you with a 'sterile' thin soup containing the building blocks of DNA based life. That might shave a bunch of time off of the time needed.
deleted 14y ago
[deleted]

3 ms·

Is it possible for life in Vostok to be genealogically isolated from life elsewhere on Earth, so that life evolved from nothing multiple times?

by twiceaday 14y ago

tdyo 14y ago
I suppose it's possible, but the fact that it is, in fact, DNA is enough to suggest it's from the last universal common ancestor (LUCA). If it shares the same ultra-conserved ribosomal etc sequences, then it's even more likely from LUCA.
jlgreco 14y ago
I believe the estimates for how long Lake Vostok water has been isolated cap out at around 25 million years. Although that is an incredibly long time, it isn't anywhere close to long ago enough to ensure a sterile condition when it was first isolated (It would need to be several billion years to proceed life as we know it already blanketing the planet). As I understand it, the prevailing notion is that abiogenesis happened only a single time, or at least only a single time that stuck. The life that already exists does a pretty good job of ensuring that any primitive re-developed life never has a chance to actually get started. You would need to completely sterilize the environment to have a shot at witnessing abiogenesis again. Maaaybe all life in the lake died, rendering it sterile, and then new life formed, but that seems super unlikely to me. Why would the existing life die if there was enough nutrients/energy to allow new life to form? (Also, 25 million years is probably far too short of a timeframe to see abiogenisis bootstrap DNA based life)
- jbert 14y ago
  Agree with that, but would also like to throw in a scenario where there wasn't a sterile environment, but conditions were harsh enough for all present life to die, leaving you with a 'sterile' thin soup containing the building blocks of DNA based life. That might shave a bunch of time off of the time needed.
deleted 14y ago
[deleted]