The Evolution of Molecules and the Origin of Life

Last time, I promised that I would say something about the evolution of molecules as Step 1 in the origin of life. The creationist organization Answers in Genesis says it’s impossible for molecules to evolve, much less to evolve into life:

Natural selection cannot be the mechanism that caused life to form from matter as it can only work on a complete living organism.

Is that true? Can natural selection only operate on complete living organisms?

This post is part of a series on creationist arguments that I encountered while studying the creation/evolution issue. I wanted to learn the truth, and creationists did not help their cause as they asserted so many obvious falsehoods. Answers in Genesis’ statement above is a case in point.

Think about it from the perspective of common sense. Wherever you have reproduction with variation, you will have natural selection: the variants that reproduce better than other variants will tend to predominate. How could it be otherwise? It’s almost tautological.

“Complete living organisms” aren’t the only things that reproduce. Molecules can reproduce, too, and researchers are closing in on what the first self-replicating molecules might have been.

RNA, the likely precursor of DNA, probably figured into the mix. The flu virus with which we’re all familiar has an RNA genome. Although viruses are in a grey area between life and non-life (not a “complete living organism”), the flu undergoes mutation and natural selection at such a rate that new vaccines must be developed every year.

The flu needs a living cell in which to reproduce, but in 2002, an RNA molecule was discovered that could replicate itself with no living thing in sight. Within a decade, experimenters had evolved it to the point where it could double in population every 5 minutes. That’s a 10100 increase every 36 hours. (See the end of this article, which contains a wealth of other information and is well worth reading.)

A bare RNA molecule is surely not a “complete living organism” yet has been observed to reproduce, mutate, and evolve with extremely successful results. What’s more, RNA just happens to be suited to carrying genetic information. Hmmm….

The formation of the first RNA molecules is still an area of active research, but intriguing progress has been made. In 2009, researchers synthesized the components of RNA, called ribonucleotides, from molecules that are known to exist in interstellar dust clouds and meteorites.

They mixed the molecules in water, heated the solution, then allowed it to evaporate, leaving behind a residue of hybrid, half-sugar, half-nucleobase molecules. To this residue they again added water, heated it, allowed it evaporate, and then irradiated it.

At each stage of the cycle, the resulting molecules were more complex. At the final stage, Sutherland’s team added phosphate. “Remarkably, it transformed into the ribonucleotide!” said Sutherland.

According to Sutherland, these laboratory conditions resembled those of the life-originating “warm little pond” hypothesized by Charles Darwin if the pond “evaporated, got heated, and then it rained and the sun shone.”

To me, that’s quite plausible. The dots are steadily being connected, folks.

4 responses to “The Evolution of Molecules and the Origin of Life

  1. Quite plausible indeed. First, while I am a creationist, I am not arguing this article from that stance. My rebut comes from the heart of your post that (to quote the original jurassic park) “life will find a way”.
    I think it’s great that scientific studies continue to cultivate and explore. I love that they make massive discoveries that drive our ability to thrive forward. I am indebted to to works of antibiotics and anesthesia (and much more).
    But the argument here is that the dots are being connected because: in a controlled environment adding controlled elements at controlled rates produced something (even something amazing). But is the water the same consistency as 10 billion years ago? Is the nitrogen level the same in the lab as prehistoric times? What about the puddles – is there any reason to believe they were warm and not hot (or vice versa). Those answers are still “we don’t know”. More importantly, those answers are (quite frankly) not plausible.
    The dots that you see connecting, are not the same dots that need connected. Great insight but irrelevant to the question of origin and the likelihood that a blind process would ever produce something as beautiful as we see today.

    • You’re right, Roger: the “warm pond” in the research I cited was a controlled environment, and favorably controlled at that. You’re also right that we don’t know everything about Earth’s early environment. But we do know that it was warm (or hot, if you wish); that there was water on it; that is was irradiated by the Sun and radioactive elements; and that it most likely contained molecules which are found elsewhere in the solar system. And now we know that such a situation can produce increasingly complex, organic molecules that are the building blocks of RNA. Don’t you find that intriguing?

      The dot-connections that this post covered were a plausible (admittedly not proven) connection from material found loose in the solar system to ribonucleotides, and the connection from one form of RNA to a more evolved form, as one example of molecular evolution. Dot-connections not covered here include ribonucleotides spontaneously joining to form RNA; bubbles of material spontaneously enclosing RNA; and such bubbles dividing by primitive means (mechanically, not by mitosis). All of these have been observed in the lab. They are not conjecture in themselves, although their role in the origin of life is speculative at this point.

      What I most want to emphasize is that something a top-notch creationist organization flatly said “cannot” happen — natural selection in something other than “complete living organisms” — has indeed happened. And they should know better than to say otherwise.

      • That’s a great point. Thank you for sharing. The only way any worldview is going to grow is by acknowledging the evidence and working with it not against it. Ultimately we may never know the original cause (even if we know different possibilities) but we should at least stay professional. Thanks again

  2. Pingback: More from Frankfurt’s “On Bullshit” | Path of the Beagle

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