Biochemistry, it turns out, is not a creationist’s friend


Oh, look. Biochemists have found a recipe that spontaneously produces all four nucleotides used in RNA.

Carell’s story starts with only six molecular building blocks—oxygen, nitrogen, methane, ammonia, water, and hydrogen cyanide, all of which would have been present on early Earth. Other research groups had shown that these molecules could react to form somewhat more complex compounds than the ones Carell used.

To make the pyrimidines, Carell started with compounds called cyanoacetylene and hydroxylamine, which react to form compounds called amino-isoxazoles. These, in turn, react with another simple molecule, urea, to form compounds that then react with a sugar called ribose to make one last set of intermediate compounds.

Finally, in the presence of sulfur-containing compounds called thiols and trace amounts of iron or nickel salts, these intermediates transform into the pyrimidines cytosine and uracil. As a bonus, this last reaction is triggered when the metals in the salts harbor extra positive charges, which is precisely what occurs in the final step in a similar molecular cascade that produces the purines, adenine and guanine. Even better, the step that leads to all four nucleotides works in one pot, Carell says, offering for the first time a plausible explanation of how all of RNA’s building blocks could have arisen side by side.

Comments

  1. Rich Woods says

    I haven’t a clue what happened here in actual reality, but I’d be much more convinced by a report which didn’t start by claiming that something started with six molecules and then jumped to a starting point which wasn’t a subset of those six.

  2. DanDare says

    Yeah I would also like to see the paper. The article seems to be a bit confused and missed important details. Time to search based on names since no citation given.

  3. keinsignal says

    This seems closer to what the article is talking about: https://www.nature.com/articles/s41467-017-02639-1
    However, that’s from January. The article references a talk Carell gave, not a paper, so it’s unclear to me if the talk was referencing this paper, or if he’s discussing as-yet unpublished results.

    In any case it’s worth pointing out that there’s no actual problem leaping from the “building blocks” to cyanoacetylene & hydroxylamine; both are fairly simple molecules (C3HN and NH2OH respectively), appear to have been produced by the Miller-Urey experiment (according to a 2008 study that went back and looked at the original vials with better equipment) and the former even appears in comets, stellar gas clouds, etc. The main hurdle to overcome is that both are reactive and unstable, so you need some way to produce them continually, but at the same time not create an environment in which the RNA bases would have been attacked and dissolved/deformed before they could do anything useful. That’s what the paper I just linked seems to be addressing, anyway.

  4. Tualha says

    Hmmm …

    First. Oxygen, not water or carbon dioxide but O₂, on early earth? Really? That seems to be what the quoted article is saying. Does not jibe with my understanding of conditions on prebiotic earth. Oh sure, maybe a little now and then when lightning or UV cracks some oxygen-containing molecules, but it wouldn’t last long in a reducing atmosphere. Maybe that’s what is meant? Little bits of short-lived O₂?

    Second. Origins of Life Workshop. A conference held by the Foundation for Applied Molecular Evolution. Supported by a grant from the John Templeton Foundation. Well, we know what they’re all about, don’t we.

    Third. Reviewing the workshop page, I see some rather badly written text laying out what seems like some rather questionable science:

    1. All compounds normally proposed as necessary for the prebiotic synthesis of RNA require a reducing atmosphere to form. However, early Earth did not seem to have a reducing atmosphere. Therefore, life could not have emerged on Earth via an RNA-first model.

    2. Even if the prebiotic precursors for RNA did manage to be formed on early Earth, they (like all organic matter given energy) would have devolved to asphalt; theory as deep as the second law precludes Darwinism having emerged from asphalt. Therefore, life could not have emerged on Earth via an RNA-first model.

    Etc.

    Seems like a few red flags to me, but I’m not a scientist, just someone who’s read a lot about science. Perhaps some actual practitioners of biology or biochemistry would like to have a look and give us your thoughts?

  5. gijoel says

    Ah but Dog’s invisible noodely appendages made those chemicals form. I explain it all in detail in my new book, “Stupid face scientists don’t know shit.” Available for $99.99.

    /s

  6. Owlmirror says

    Oxygen, not water or carbon dioxide but O₂, on early earth? Really? That seems to be what the quoted article is saying.

    I get your complaint, but I think it’s just that the article is confusingly worded. The papers by Carell reference the typical simple molecules of the early atmosphere. There isn’t even a hint that his ideas imply that free oxygen molecules existed in the early atmosphere, or are required for the chemical pathways described.

    That having been said, I agree with you about the red flags. I note the last paragraph on this page:

    http://templetonorigins.ffame.org/OriginsConfSchedule2018.aspx

    We would like very much to walk out of this workshop with, if not a solution to the prebiotic synthesis of oligomeric RNA, then at least a clear understanding of where the remaining problems are and how we should approach solving them. Or, of course, that they cannot be solved at all, because life emerged in a different way.

    Uh . . . huh.

  7. =8)-DX says

    “These, in turn, react with another simple molecule, urea.”

    So it wasn’t a mud-puddle or a primal ooze. It was an underwater piss-pot. I am honoured to have such distinguished ancestry.
    =8)-DX

  8. wzrd1 says

    @6, actually, it’d just be O, for an energetically cleaved oxygen. There, you have a radical looking to become a cause. ;)
    Which is rather like what happens in actual cellular life, free radicals being reacted in controlled processes within a cell. With uncontrolled processes being utilized by specific immune cells, which is why once they produce superoxides, they self-destruct. But, with controlled processes, continues without cellular damage.
    Think of a hydrogen pump, not dihydrogen, but a proton pump. An ion being used as a process component. It’s ubiquitous in life. And in nature, outside of cellular life, in a rather random and disorganized fashion.
    https://phys.org/news/2017-10-evidence-life-earth-meteorites-splashed.html

  9. mnb0 says

    Biochemistry totally proves creacrap. Those biochemists intelligently designed the recipe. QED.

  10. mountainbob says

    Took a couple clicks through various links, but the Carell location is an institute within the University of Munich. Guess my favorite young biology professor thought everyone would know that. The publication is near the top of their list of pubs. Here’s a link: https://www.carellgroup.de/

  11. DanDare says

    Looks like everyone in poopy heads echo chamber disagree that the information presented is of sound quality. What kind of weird group think is this? Aren’t we all supposed to agree thoughtlessly to whatever is presented?

    It gives me hope that this site has people who are reasonable and not ‘post truth’.

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