- yeahitslikethat 10 days ago
Why can't it be that new organisms are bubbling up from the thermal vents or bubbling hot springs all the time?
Why do they say every thing came from a single origin cell?
Seems like I'd it happened once, it can happen again!
- jonmc12 10 days ago
"It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present. But if (and oh what a big if) we could conceive in some warm little pond with all sorts of ammonia & phosphoric salts, light, heat, electricity, etc present, that a protein compound was chemically formed, ready to undergo still more complex changes, at the present day such matter would be instantly devoured, or absorbed, which would not have been the case before living creatures were formed"
~Charles Darwin, in a letter to Joseph Hooker (1871)
I heard researcher Bruce Damer explain how Darwin was likely correct in this letter. As we understand it today, enzymes and oxygen would prevent a second biological genesis. Also, there is less "feed stock" of star dust falling on our present warm little ponds. https://www.mindpodnetwork.com/future-fossils-109/
- acqq 9 days ago
A truly very impressive quote, given what was available to Darwin in 1871. At that time many scientists didn't want to accept that atoms exist:
Adolf Wilhelm Hermann Kolbe "(1818-1884), a German organic chemist described as one of the greatest of that time" denied that molecules as we know them today existed. "The French chemist Pierre-Eugéne Marcellin Berthelot (1827-1907)" "exerted his considerable power as a government official to prohibit the teaching of atomic theory." "Austrian physicist Ernst Mach (1838-1916), and German physical chemist Friedrich Wilhelm Ostwald (1853-1932)" "preferred the consideration of perceived data to that of hypothetical atoms."
Only much later "in 1908 Ostwald became convinced that experiments had finally given proofs of the discrete or particulate nature of matter. In 1912 Poincaré declared that "[A]toms are no longer a useful fiction … The atom of the chemist is now a reality.""
- pgt 9 days ago
I had not considered that initial life, which created enzymes and oxygen would inhibit subsequent biological genesis. This seems to contribute to the Fermi Paradox.
- YUMad 10 days ago
Prolly not, they'd have to outcompete 3.5 billion years of evolution to survive.
If you're interested in stuff like that, google 'rna world'. It is likely that dna-based life evolved out of rna-based life and outcompeted it.
- BurningFrog 10 days ago
So if DNA based life once outcompeted the pre-existing RNA based life, that implies that the first mover advantage in Life isn't that great after all.
- YUMad 10 days ago
> So if DNA based life once outcompeted the pre-existing RNA based life, that implies that the first mover advantage in Life isn't that great after all.
Dna life evolved out of rna life.
- folli 9 days ago
DNA based life is essentially build on the basis of RNA based life with the extra twist of long-term storage
- visarga 10 days ago
It is, for genes, though.
- dzdt 10 days ago
Lots of scientists have looked for evidence of multiple origins of life, but so far no evidence has turned up. Every organism found so far fits on a tree of life using a common set of genetic molecules.
It would be an amazing discovery to find a second tree of life though!
- TheSpiceIsLife 10 days ago
What if the solution-space is so constrained we can't tell the difference between new emergence and common genetic molecules.
- lovemenot 10 days ago
Isn't chirality (twist direction) of DNA thought to be purely arbitrary, yet 100% consistent in all observed species?
Why is opposite chirality DNA not a thing?
- ibeckermayer 10 days ago
I’ve independently had the same question. There are a lot of assumptions in our contemporary cannon that are unchecked (afaik, but open to being told I don’t know what I’m talking about since this is by no means my area of expertise).
It may even be the case that this isn’t possible to know, at least given the evidence at hand. Theories should simply take note of this ambiguity, by qualifying with “if X is the case, that means theory Y is true”
- not_kurt_godel 10 days ago
Psst, I think you meant "canon" :)
- ibeckermayer 9 days ago
Na I meant the thing on pirate ships (you're right, thanks)
- shitberg 10 days ago
I'd hazard an alternative hypothesis that other forms of life are so radically different at a chemical level, that we don't even recognize them as alive.
- mevile 10 days ago
Such a thing would be outmatched in the competition for resources. It's probably much harder for new life to form when there's already existing life around to take whatever materials are required for life to exist.
If life coming to be is already rare enough that we don't see any evidence of it elsewhere in the universe, how much more rare should one expect for it to be under these circumstances?
- ibeckermayer 10 days ago
You don’t know that such a thing would be outcompeted for resources. For example, life may have evolved independently on opposite sides of the earth in quick succession — there would be no competition for resources
- changoplatanero 10 days ago
If some new life form emerged from scratch it would be pretty easy to detect right?
- acqq 10 days ago
It's science, not a "debate club." It's simply about trying to reconstruct something based on the samples which are still incomplete (and will remain very hard to improve):
"Specific sediment horizons, previously shown to contain high abundances of novel archaeal lineages were subjected to metagenomic analysis. Due to the low density of cells in the sediment, the resulting genetic sequence does not come from an isolated cell, as would be the case in conventional analysis, but is rather a combination of genetic fragments. The result was a 92% complete, 1.4 fold-redundant composite genome named Lokiarchaeum.
The metagenomic analysis determined the presence of an organism's genome in the sample. However, the organism itself has not been cultured."
Now knowing that, the end of the article is what is the point:
"But analyses of the Asgard archaea, including the Lokis, remain limited. “What people are really waiting for is the isolation of a member of these lineages,” says evolutionary microbiologist Simonetta Gribaldo at the Pasteur Institute."
The other point is:
"Other scientists are reserving judgement: “Trees change,” is a common refrain."
It seems some editors or the article writers think that when they cover something as a "debate" there's a "win" somewhere for them (1). "Mysterious" too. But it's confusing the causal readers who then miss to understand how amazing is what we already know and how fine these details are that still aren't known.
1) It's also worth noting that there are some rich entities which pay a lot of money to "promote doubt" in the successes of natural sciences. Maybe even the non-biased editors "pick the signal" generated by the public addressed by such groups and then think that they just "reached more readers" with such titles or approaches in the articles. I would have expected from "Nature" not to, however.
- Angostura 9 days ago
> It seems some editors or the article writers think that when they cover something as a "debate" there's a "win" somewhere for them
Except that, in this particular area of uncertainity there has been debate, heated opinion and entrenched positions. Nature is reflecting the messy, human business of the process of advancing science.
- acqq 9 days ago
It is messy but as I’ve quoted, the majority of scientist had the following view:
“Other scientists are reserving judgement: “Trees change,” is a common refrain."
Which is a correct approach to the topic: it’s easy to blow something up out of proportions when the scale is ignored.
- tathougies 9 days ago
> It's science, not a "debate club."
To be clear... the scientific method is literally a debate club.
- acqq 9 days ago
> To be clear... the scientific method is literally a debate club.
To be clear... it's literally like a game of chess, only without the two dices:
Worth reading how the science already looked like in 1683. Please don't try to dumb it down.