A few weeks ago, I linked to a very interesting paper on how life may have evolved. In response to some comments here, the abstract has been revised. Here is the note to me in email:

The abstract was revised to (hopefully) eliminate ambiguity and make it clearer that Sylvain’s proposed chemical steps are not just a partial solution, but rather, go from the first reaction all the way to all the biomolecules necessary to “usher in the RNA world.” The full-picture illustration was also added on the home page to help readers grasp the scope of what is being offered.

To me, one of the compelling aspects of this is that all the relevant biomolecules form in one location through ‘room temperature’ chemical steps that do not require anything exotic.

Topics relevant to the Origin of Life that are addressed in this paper:

1. Why the relevant amino acids are all left-handed

2. Why there are 20 standard amino acids, and why those 20
3. Why the relevant amino acids are all “alpha-amino”
4. Why the relevant sugars are right-handed
5. The origin and preservation of homochirality
6. The origin of nucleobases A, G, C, U
7. The origin of RNA

8. The origin of the lipids

To put this into perspective, each one of these topics is a major big deal. That this model shows them as possibly being parts of interrelated cascading chemical steps is stunning. It is interesting to note that these chemical steps take place, not in a “primordial soup,” but in a sheltered microenvironment of a mineral host structure. Since these proposed reactions do not work in water, the concept of life originating in a “primordial soup” may have mislead Origin of Life chemists for many decades.

We’ll see where it goes. If it can actually tackle abiogenesis, it is a big deal.

…and scientific paradigm shifts, from A Jacksonian.

[Via Joe Katzman]

An interesting new theory, for those well versed in organic chemistry.

[Update in the afternoon]

This seems related:

Not content with achieving one hallmark of life in the lab, Joyce and Lincoln sought to evolve their molecule by natural selection. They did this by mutating sequences of the RNA building blocks, so that 288 possible ribozymes could be built by mixing and matching different pairs of shorter RNAs.

What came out bore an eerie resemblance to Darwin’s theory of natural selection: a few sequences proved winners, most losers. The victors emerged because they could replicate fastest while surrounded by competition, Joyce says.

“I wouldn’t call these molecules alive,” he cautions. For one, the molecules can evolve only to replicate better. Reproduction may be the strongest – perhaps only – biological urge, yet even simple organisms go about this by more complex means than breakneck division. Bacteria and humans have both evolved the ability to digest lactose, or milk sugar, to ensure their survival, for instance.

Joyce says his team has endowed its molecule with another function, although he will not say what that might be before his findings are published.

More fundamentally, to mimic biology, a molecule must gain new functions on the fly, without laboratory tinkering. Joyce says he has no idea how to clear this hurdle with his team’s RNA molecule. “It doesn’t have open-ended capacity for Darwinian evolution.”

Not yet.