To me, these are clearly not independent paths, but rather the branching of proto-life into two of the great kingdoms of life. It’s a stretch to call this two origins rather than a branching.
Then a couple billion years later, one of em ate the other, and rather than destroy it, they both started a symbiotic relationship, and we were off to the eukaryotic race. This is all the same web of life. Not two independent streams.
Probably this. How would we know what such 'proto-life' (perhaps even just some self-replicating soup of chemicals, no cell wall) would look like? Where to find it? How rare its occurence? Etc etc.
Scientists might not even recognise it if happened right in front of them.
I'd put my money on coming up with a more general definition of "life", and then looking for short(est) pathways from "soup of random chemicals" to "something in there that replicates (parts of) itself".
Doesn't need to look like life as we know it, as long as some elements of "self-organising structures, something being replicated" are there.
It's possible OoL requires some exponentially unlikely step. We wouldn't realize that because of observer selection: had the step not occurred, we wouldn't be here to be thinking about it. There's a huge complexity gap between the stuff produced in OoL experiments and the simplest known life.
It's also possible OoL requires conditions that no longer exist on Earth, or that only existed in the early Earth (or wherever life got started in the Solar System). For example, if it depended on the existence of short lived radioactive isotopes or free ammonia.
The fact that it doesn't is a pretty simple solution to the Fermi Paradox.
* https://en.wikipedia.org/wiki/Great_Oxidation_Event
one of my absolute favorite PBS Space Time on the subject
> “When we react phosphite, a form of phosphorus that naturally occurs in hydrothermal vents, with organic compounds, we get metabolic phosphorylation reactions overnight in water. Phosphite and palladium replace ATP and enzymes; it’s amazing, and it makes early evolution a lot easier to grasp” says Schlikker.
As far as I know, there are no palladium enzymes ... checks ... ok, no _natural_ ones (that we know of). Which is interesting, as other enzymes in metabolism that use metals seem to have 'adopted' the metal(s) as a cofactor - like nickel, iron, molybdenum, even vanadium in at least one case.
Anyway, it does provide a nice reason that bacterial and archaeal cell membranes are different.
Should be "Life left mineral substrate at least twice" or some such. The research is interesting, but they're playing word games in the telling of it by saying the most recent common ancestor of all life wasn't alive (because it was dependent on a mineral surface), but two of it's children gave rise to lineages that were.
I assume that the difference here, is that it went completely to zero, before restarting. The other times, there was a bit clinging on, that seeded the restart.
The reality we will never be able to replicate creation of life nor find life on other planets (except via contamination). it's why we've never gotten any closer. and i'm not even religious
* https://en.wikipedia.org/wiki/Formation_and_evolution_of_the...
But high level life was likely a series of complex accidents that is not reproducible or would be radically different than us
One of my absolute favorite PBS Space Time on the subject
What is the basis for this assertion?
As I see it life was clearly designed by God.
Theistic Evolution is wide-enough belief, especially with Protestants.
Or is that the joke and I'm missing it?
Which one? There are so many to choose from...
And what created that God? I know it's turtles all the way down but still want to know.
Personally, I don't believe in any religions. They were all developed before we had a much clearer idea of how our world works and there's just too much folklore mixed in with actual, yet primitive, philosophical discussions to abide by any of it. But like with the simulation theory, we have no way to know what exists outside our time and space so you shouldn't worry. If there is some bored extra dimensional teenager simulating our universe on their GPU, it ultimately doesn't matter because we'll never know.