On the transition from non-life to life A replicating lifeform inside another lifeform will kill it, cold.
— MikeL
Well it was nice knowing you then. Goodbye to you and the 100 trillion bacteria living mostly symbiotically in your gut. And the vast variety of retroviruses hijacking a ride on your DNA. — apokrisis
Well there's inside the body alongside our cells and there's inside the cell itself. The bacterial flora of our gut are not inside our cells, unlike the mitochondria. And if any of those retroviruses hitching a ride decide they might just pop out and see what's happening, guess what?
That was a very smart decision. When did it come to this decision? Before or after it killed the host?
— MikeL
Did you miss the key point? The host was a handy supply of its food. While it was a handy source of energy for its host. So the situation was SYMBIOTIC. :) — apokrisis
I agree that the host was a very good supply of food that the host cell had intended to use for itself. The mitochondria also provided energy for the cell, however, I think that some tweaking may have been needed here before they got it right. In the meantime you have a replicating cell that has invaded another replicating cell and is consuming it's resources. Not so symbiotic. Not yet.
They went together so exactly that they created a whole new evolutionary era. All their fellow microbes were left in the dust. In 4 billion years, the other guys have shown no essential structural change. — apokrisis
Wow, you've skipped right to the end of the story.
But it floats in a gene pool - a metagenome - of 18,000 genes that it can pick up as it needs as food sources change and a different kind of digestion might be needed, or whatever the environmental challenge happens to be. — apokrisis
The megagenome is interesting and you might have me there. I'll have to check it out.
In the meantime you have one cell membrane bound organism inside another cell membrane bound organism - What happened here? Did the mitochondria extrude its genome through its own cell membrane, (essentially throwing it away) have it get entangled with the host genome, somehow re-capture it's genome (lucky it hadn't floated off in the ocean)? And then in this seemingly lucky (for recapturing the genome it flushed out of its body) event suddenly find out that it was not so good after all, for in the recapturing of it's own genome processes it failed captured any of the host genome while also unfortunately losing the genes most critical for its own survival.
But not to worry because then the DNA of the host cell begins producing the promoters and transcription factors required for the mitochondria to survive (before the mitochondria does actually die of course - so within one generation unless it is assault of a mitochondrial army against the archaeon which could be feasible [ramping up the probability index for you there]).
So the happy ending for this chaotic disaster is the perfect regulation of the health of the mitochondria and the division of the mitochondria by the host cell, in exchange for energy it learnt to use. Not bad. Chalk one up for nature.
Could they? How did they come to that arrangement? Enterprise bargaining? The blind mitochondria said to the blind cell, "I don't know what the hell you are or where the hell I am but here comes some genes. Catch."
— MikeL
This is a bit of smart alec reply given the realities of bacterial and archaeon sex. — apokrisis
You're right, it was a bit tongue in cheek. I was just playing with you. Great to get your ideas, they always make me think.