3 ms·

It's one thing to say that a particular evolutionary step is a zillion-to-one fluke and another to say that the possibility of any fluke leading to more complex

It's one thing to say that a particular evolutionary step is a zillion-to-one fluke and another to say that the possibility of any fluke leading to more complex life is of similar probability. Maybe there are or will be found to be more weird hybrids in nature? I vaguely recall reading something about how someone found a hint that brain cell communication may have mechanisms that resemble viruses (and/or prions). If you don't see eukaryotes as inevitable, then what about brains? Social insects? What about human civilization? Biotechnology? I don't think it contributes a lot to declare they are inevitable, but I don't see why eukaryotes would be a singular example of increasing organization that's different from all the others. Zooming out, it seems like a lot of random events merge into an exponential curve.

cmrdporcupine 6y ago
The argument is basically from the fact that it occurred once and never again. Eukaryotes are the result of a symobiosis between archaea and bacteria, and we have yet to find any intermediary steps nor anything else that looks like a similar occurrence in nature. And yet there's nothing stopping that fact from happening again and it hasn't. Though apparently there is one tantalyzing find that may or may not amount to something. And also it seems to have taken 2 billion or more years for it to happen. And bacteria and archaea are pretty much "happy" the way they are. The development of eukaryotes broke an energy and complexity limit because of the symbiosis between mitochondria (which were once free roaming bacteria) and the host cell. It freed up the host cell to create genetic complexity orders of magnitudes higher than what a prokaryote can produce. Complex life cannot develop from prokaryotes because they simply can't produce enough energy to make it happen. Nor do they need to, they are extremely successful.
- gbrown 6y ago
  > And yet there's nothing stopping that fact from happening again and it hasn't. This doesn't quite ring true, since the environment which a new Eukaryotalike would have to compete in is a lot different now, since there are lots of Eukaryotes around to eat its lunch.
  - cmrdporcupine 6y ago
    Nick Lane has a rebuttal to that, but I don't recall what it is off the top of my head. His books are worth a read.

cmrdporcupine 6y ago

The argument is basically from the fact that it occurred once and never again. Eukaryotes are the result of a symobiosis between archaea and bacteria, and we have yet to find any intermediary steps nor anything else that looks like a similar occurrence in nature. And yet there's nothing stopping that fact from happening again and it hasn't. Though apparently there is one tantalyzing find that may or may not amount to something. And also it seems to have taken 2 billion or more years for it to happen. And bacteria and archaea are pretty much "happy" the way they are. The development of eukaryotes broke an energy and complexity limit because of the symbiosis between mitochondria (which were once free roaming bacteria) and the host cell. It freed up the host cell to create genetic complexity orders of magnitudes higher than what a prokaryote can produce. Complex life cannot develop from prokaryotes because they simply can't produce enough energy to make it happen. Nor do they need to, they are extremely successful.

gbrown 6y ago
> And yet there's nothing stopping that fact from happening again and it hasn't. This doesn't quite ring true, since the environment which a new Eukaryotalike would have to compete in is a lot different now, since there are lots of Eukaryotes around to eat its lunch.
- cmrdporcupine 6y ago
  Nick Lane has a rebuttal to that, but I don't recall what it is off the top of my head. His books are worth a read.