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ringobob t1_j8hwmin wrote

Reply to comment by ChemicalRain5513 in Is it possible that abiogenesis is still happening right now on earth? by dolekanteel

Hard to imagine how that might work in the overall landscape of evolution. Let's assume there were two successful evolutionary lineages that began from two separate abiogenesis events. Do you expect both lines to produce their own, say, bacteria? Plants? Animals? I think what you would expect, hypothetically, is that one line produced its own kingdoms of life, and the other produced its own kingdoms of life, and they'd be unrelated.

So, like, you'd have fungus over here and plants over there, but they'd be entirely unrelated. And that's not what we see. They are related.

The other alternative is that these simple forms of life can intermix. In which case, it makes less sense to think of it as happening multiple times, and more sense to say they were so undifferentiated as to be the same thing. This is sort of a chicken and egg problem. If the conditions necessary to spawn life essentially produced a population, rather than an individual, then I don't know that we'd be able to tell the difference without seeing it in action. And the result would be that we're descendents of all of that life, rather than a single moment of abiogenesis.

Intuitively, it would be surprising for two separate abiogenesis events to produce two forms of life that are that compatible, but perhaps such life is so simple that there's not enough complexity to actually differentiate them.

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JohnOliverismysexgod t1_j8hzmjk wrote

When I was a kid, I learned that any instances after the one that took would not survive because such instance would be the perfect food, so it would be gobbled up by the life already here.

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Ok-Dog-7149 t1_j8iukfx wrote

This would seem to make some assumptions about relative proximity between the two.

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Geobits t1_j8izxui wrote

If they were close in time, sure. It's hard to imagine a biogenesis event now, for example, because existing life is so ubiquitous that it'd have a hard time competing against everything.

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Anarchaeologist t1_j8izjp5 wrote

Do you have an area in mind that this might happen? Every environment on Earth that's suitable for organic life's survival seems to already be swarming with microbes

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cesarmac t1_j8i79xk wrote

Well i think he's asking about the possibility that ancestral biological structures might have been very similar. Like say ancient vacuoles maybe existing on their own and using RNA as a means of building other vacuoles. The RNA strands might have been extremely simplistic by today's biological standards.

Then you have other extremely simplistic structures that originated somewhere else, using RNA as means of doing extremely simple and menial tasks. Then these proliferate and eventually come into contact with each other and by coincidence form more complex relationships as single structures over time, kind of how the mitochondria is theorized to have become a part of the cell millions of years later.

When they combine maybe it would be difficult to determine that they were two distinct lines of life because they used the same means of relaying genetic information.

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ChemicalRain5513 t1_j8izxli wrote

Clearly all the dna of eukaryotes is so related that it cannot be due to chance. But could it be that archae and bacteria formed from separate abiogenesis events?

Or could eukaryotes have formed multiple times? We know that encapsulation of bacteria to form organelles has occurred at least twice, namely for mitochondria and for chloroplasts. Could it be that different eukaryotic kingdoms have mitochondria that are not related?

>If the conditions necessary to spawn life essentially produced a population, rather than an individual, then I don't know that we'd be able to tell the difference without seeing it in action.

Yes this is essentially what I meant, the question whether all life comes from one single cell, of if at some point the conditions were such that many cells formed that were very similar, maybe even with similar dna that was being copied, floating around.

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