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>The chemistry is also a “strong indication” that the appearance of RNA-based life was not an exceedingly lucky event, but one that is likely to happen on many

>The chemistry is also a “strong indication” that the appearance of RNA-based life was not an exceedingly lucky event, but one that is likely to happen on many other planets, he adds. Does this mean a new lower bound for the fl factor for the drake equation ?

The_rationalist 7y ago
Than why all earth living beings come from one common ancestry rather than many different ones?
- UnFleshedOne 7y ago
  First mover advantage probably. If abiogenesis is common but not too common, whatever starts reproducing first might have a few billion years to spread everywhere and take over all possible niches.
- TheRealPomax 7y ago
  Mostly: because billions of years have passed. Even if it turns out there we millions of different self-replication mechanisms that were complex enough to give rise to (an abstract form of) competition, early Earth has a period of hundreds of millions of years in which each and everyone one of those had plenty of time to run their course to extinction. Remember that that single common ancestor was _not_ alone on the planet. They might have been millions or even hundreds of millions of other potential ancestors, but if there were, all of them died out before the start of the fossil record.
  - Grue3 7y ago
    At any point in time there was likely a great variety of ecological niches on Earth. It seems weird that one kind of organism would achieve total global domination. For example Bacteria and Archaea have diverged relatively early on the scale of evolution, and both of these domains have survived until the modern times without one dominating the other.
- scoopertrooper 7y ago
  The 'common ancestor' dates back to about the same time as the late heavy bombardment. It's been theorised that earth may have been suitable for life earlier than originally hypothesised, but the bombardment wiped the record. If this is true, then there may have been many independently evolved microorganisms pre-bombardment, but only a few colonies survived because they happened to live deep underwater near volcanic vents. Perhaps also, in this era of reduced genetic diversity, one colony was especially capable of adapting to the new environment and quickly outcompeted all the other surviving colonies. Or maybe aliens did it. Who knows.
pfdietz 7y ago
No. The problem is that one would expect the "easy" steps to be resolved first, so uncovering them says very little about how unlikely the hard steps are. That "strong indication" comment is BS.

The_rationalist 7y ago

Than why all earth living beings come from one common ancestry rather than many different ones?

UnFleshedOne 7y ago
First mover advantage probably. If abiogenesis is common but not too common, whatever starts reproducing first might have a few billion years to spread everywhere and take over all possible niches.
TheRealPomax 7y ago
Mostly: because billions of years have passed. Even if it turns out there we millions of different self-replication mechanisms that were complex enough to give rise to (an abstract form of) competition, early Earth has a period of hundreds of millions of years in which each and everyone one of those had plenty of time to run their course to extinction. Remember that that single common ancestor was _not_ alone on the planet. They might have been millions or even hundreds of millions of other potential ancestors, but if there were, all of them died out before the start of the fossil record.
- Grue3 7y ago
  At any point in time there was likely a great variety of ecological niches on Earth. It seems weird that one kind of organism would achieve total global domination. For example Bacteria and Archaea have diverged relatively early on the scale of evolution, and both of these domains have survived until the modern times without one dominating the other.
scoopertrooper 7y ago
The 'common ancestor' dates back to about the same time as the late heavy bombardment. It's been theorised that earth may have been suitable for life earlier than originally hypothesised, but the bombardment wiped the record. If this is true, then there may have been many independently evolved microorganisms pre-bombardment, but only a few colonies survived because they happened to live deep underwater near volcanic vents. Perhaps also, in this era of reduced genetic diversity, one colony was especially capable of adapting to the new environment and quickly outcompeted all the other surviving colonies. Or maybe aliens did it. Who knows.

pfdietz 7y ago

No. The problem is that one would expect the "easy" steps to be resolved first, so uncovering them says very little about how unlikely the hard steps are. That "strong indication" comment is BS.