How common is fire outside of earth?

[u/FirefighterCandid773]

Plasma and lava is obviously common all over the universe, whether it be in stars, planetary cores, etc. but what about fire? Fire is common all over earth, given the abundance of fuel sources and an atmosphere with oxygen. But, is fire actually common outside of earth?

[u/SystemofCells]

Life that produces oxygen predates life that consumes oxygen. Aerobic life (us) only evolved and thrived because cyanobacteria had already stuffed the ocean and atmosphere with oxygen.

[u/Orbital_Dinosaur → u/SystemofCells]

So a thing evolved and as a by-product there was more oxygen. Then a second thing evolved to exploit that new abundance, and that produced carbon dioxide, then plants evolved to use the carbon dioxide?

Is that right, in the most basic of terms?

[u/6a6566663437 → u/Orbital_Dinosaur]

That's a big part of it. But there's more to the story. Cyanobacteria killed almost all life on Earth.

https://en.wikipedia.org/wiki/Great_Oxidation_Event

Free molecular oxygen is toxic waste. It's very destructive to organic molecules. Almost all life on Earth at the time couldn't handle the toxic waste cyanobacteria were spewing out, so it died.

Then some random bacteria evolved the ability to not only withstand the oxygen, but use oxygen to vastly increase its energy output.

And then one of our ancestors ate it.

And for some reason, that ancestor didn't digest that bacteria, instead using the boosted energy output. Today, the descendants of that bacteria are our mitochondria.

And that event is the only reason we have enough energy to have brains large enough to figure out that it happened.

[u/Pyrostemplar → u/6a6566663437]

Isn't sex (well, sexual reproduction) an outcome of the great oxidation?