Protein discovered inside a meteorite(phys.org) |
Protein discovered inside a meteorite(phys.org) |
there is a mismatch between the title of that article and the level of confidence these researchers were expressing.
the preprint is here:
[0] For example, from the conclusion: "The average molecular deuterium excess above terrestrial is (25,700 ± 3,500)%, or a D/H ratio of (4.1 ± 0.5) x10^-3, comparable to cometary levels, interstellar levels and also equal to the highest prior report in micro-meteorites."
At some level, these researchers seem to be doing basic chemistry. Maybe they're not characterizing the implications correctly or maybe they haven't controlled contamination, but if proper research discovered extraterrestrial protein it would probably generate papers that looked like these.
[0] https://scholar.google.com/scholar?cites=8914643017753968792...
the origin of the elements composing the organic compounds is very likely non terrestrial as indicated by isotopic ratios.
the time and nature of the assembly of these compounds is not apparent.
assembly may have been primordial involving cometary CN and production of polyglycine.
assembly may have been metallo-organic catalysis, at any time from formation of the parent "rock" chondrite, upto the time circa. discovery
a biological process may have been involved with assembly, after impact of the meteoric subject with earth.
the suitability of this material for exploitation by chemolithotrophic organisms in the past should not be overlooked
what it looks like to me is that a couple just received a good research grant set up a laboratory in started putting it to good use. we need to find these polymers on samples that are still off world, or we need to be able to demonstrate such polymerization in an environment mimmicking conditions off planet.
> but once the findings are confirmed...
which should be "but if the findings are confirmed"
I believe they successfully avoid contamination, but I have no idea how.
[edit] This is the full pdf below, if you look at page 2, you will see how they generated prepared and analyzed the sample
https://arxiv.org/pdf/2002.11688 [PDF]
and this is the meteoritic report for the subject:
https://www.lpi.usra.edu/meteor/metbull.php?code=95
the thing with structured peer review is that noone knows it all , and a team of specialists [review commitee] are much more powerful than a team of generalists, to the end of revealing any artefacts of procedure, or hair splitting levels of knowledge regarding metalo-organic chemistry that could explain abiotic process that would produce amino acid polymerization.
If my memory serves it was as if molecules fit together like a lock and key except this molecule's key/lock combo was inverted.
Apologies if I'm bungling it up but it felt as though it was significant. As if the molecule found was unlike any molecule on earth due to its lock/key orientation.
https://en.wikipedia.org/wiki/Chirality_(chemistry)#In_bioch...
"The origin of this homochirality in biology is the subject of much debate.[12] Most scientists believe that Earth life's "choice" of chirality was purely random, and that if carbon-based life forms exist elsewhere in the universe, their chemistry could theoretically have opposite chirality. However, there is some suggestion that early amino acids could have formed in comet dust. In this case, circularly polarised radiation (which makes up 17% of stellar radiation) could have caused the selective destruction of one chirality of amino acids, leading to a selection bias which ultimately resulted in all life on Earth being homochiral."
So you'd expect to see both at a 50/50 ratio in a meteorite, if you see any at all. That's just chemistry.
The third author of the referenced paper does have a page at Harvard, here: http://www.people.fas.harvard.edu/~mcgeoch/index.html where she says she is at the "Department of Molecular and Cellular Biology, Harvard University" but she's not listed as faculty in that department here: https://www.mcb.harvard.edu/faculty/faculty-profiles/
Could be a student... but do a search for Malcolm. W. McGeoch, Sergei Dikler, Julie E. M. McGeoch from Plex Corporation, Bruker Scientific LLC and Harvard University
and you will start to wonder if these people even know their names have been used in this article. Shame on phys.org for not calling the author for a quote or doing any other legwork to convince me this is anything other than a UFO hoax or the output of a paper-writing AI. It could be, but ...journalist please.
https://www.directory.harvard.edu/
Associate of the Department of Molecular and Cellular Biology.
Previous papers on arxiv (just click the author name on the abstract page):
https://arxiv.org/search/astro-ph?searchtype=author&query=Mc...
I am all for healthy skepticism, but insinuating a hoax based on an ad hominem without even spending a few seconds to do a quick check is not.
It's a bit of a stretch to call this a "protein" TBH. The protein part is composed of only glycine, so there's really no information (e.g. DNA) required to synthesize it, just glycine and a chemical environment that would cause it to polymerize. The caps at either end are not protein components at all, as the article mentions, and protein backbones on Earth are never cyclic afaik.
But, it's still a very complex organic molecule ofc, which is very significant on its own, and its similarity to protein is evidence that protein-based life could be more common.
I have always found the idea of panspermia to be a bit of a cop-out as it totally sidesteps the problem of abiogenesis: it’s all fine and well to say “life came from space” but you still need to explain how life arose in space to begin with.
Life arose very quickly on Earth, almost as soon as it was capable of surviving, so it raises the interesting question: were we just lucky, or is it easy to spawn life, or did it come from elsewhere? The answer creates very different pictures for what Earth-like planets elsewhere in the galaxy actually look like.
https://en.wikipedia.org/wiki/Chirality_(chemistry)#In_bioch...
And there's a general idea that a purpose of life may be to "spread" through the universe — like, why die here on this planet instead of settling the universe... given the actual choice, there's no solution but to leave eventually, when your star dies (if only locally to "fix" it by adding more fuel in it, e.g. hydrogen).
So this, if true, is really just one more reason on top of an already high pile as I see it.
Under this assumption I'd most like to estimate the number of discrete seeders in our vicinity and their interconnectedness.
It could show that life travelled here on meteorites etc. But it also could mean: life arises elsewhere, life commonly arises in the universe and may have also arisen here (and many places) independently.
How so? "We" could predate this protein.
I don't mean to be glib, but space is very large and time before our planet was formed is very long.
I assume that if it was easy here in those first few hundred million years, it had already been even easier in many elsewhere places. Any one, or multiples of which could have seeded us with as yet locally unavailable precursors and possibly even life.
So when somebody can say "It has been peer reviewed", it at least helps get past the crank filter. And conversely, "It hasn't been peer reviewed" can be a shortcut for "I'm not going to put a lot of effort into this without better reason than I've heard so far."
It's not so much an argument as a way of shortcutting an argument. Though note that doesn't really apply to a top-level comment on HN, where nobody has really advanced an argument yet and simply ignoring it might be a more useful strategy.
there has to be independently reproducable results from independent research over time until the variation of outcomes is known, for some sciences this can be a very long process for very unscientific reasons.
one thing not addressed is that the isotopic elements of the meteoric fragment may have been incorporated by a terrestrial biological or chemical process
for example PCR has a lot of credit, the central dogma of molecular genetics has a lot of credit, but there are exceptions being found in very niche cases such as reverse transcriptase and the HIV virus.
those experimental protocols that have been reviewed and found to be non deficient at the time of review are often repeated in principle as they are used for a common tool.