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Long Story Short Debunks Another Tall Tale of Self-Replication

Image source: Discovery Institute.

As I pointed out last week, the latest episode of Long Story Short reviews popular YouTube videos on the origin of life. These videos promote the materialist view, encouraging millions, including students, to believe that life started through purely natural processes (abiogenesis). However, as Long Story explains, these videos subordinate science to ideology. Actual science clearly contradicts their teaching. Now, let’s review the popular video “What Is the RNA World Hypothesis?” by Jon Perry and the YouTube channel Stated Clearly, which claims to be “in line with NGSS standards [Next Generation Science Standards] for use in classrooms” and boasts the authority of NASA, the National Science Foundation, and the Center for Chemical Evolution. 

The video, as you’ll know if you have watched the new Long Story episode, provides an animated depiction of self-replication of RNA, with the following narration (at 2:29):

Researchers have found that with a little bit of assistance, base pairing allows chains of RNA to replicate and evolve. Here’s how it works: When a long chain of RNA is suspended in cool water with high concentrations of free nucleotides, the chain can act as a template for its own replication. Nucleotides automatically base pair with their partners on the existing chain. If their backbone atoms form chemical bonds with each other — and, by the way, this is the part that currently requires assistance from researchers, we’re not yet sure how this would have happened in the wild — a complementary RNA strand is born. One with the exact inverse sequence of the original. If the water is then heated, paired bases lose their grip, allowing both chains to act as templates when the cycle repeats.

Many Contradictions to Science

The narration and animation provide a lengthy list of contradictions to well-established science.

The first statement — “When a long chain of RNA is suspended in cool water with high concentrations of free nucleotides” — is accompanied by animation that shows a straight, long strand of RNA. However, for RNA to function as a ribozyme (a catalyst to encourage useful reactions) it must be folded — bonded to itself in ways that produce useful shapes. A straight strand of RNA has no function, so replicating it serves no purpose in advancing toward life. The video should therefore have depicted a folded RNA. But it can’t depict a folded RNA, because an RNA must be unfolded to be replicated. It is possible for a folded RNA to become unfolded at higher temperatures, but the video explicitly says, “in cool water.”

A Challenge on the Early Earth

The next statement, “with high concentrations of free nucleotides,” would be quite a challenge on a prebiotic Earth. If a prebiotic Earth could have produced nucleotides through purely natural processes, we know that it would also have produced millions of other interfering or toxic molecules, in a hopelessly inseparable mixture of “tar.”1 The problem is compounded by the challenge of homochirality: each RNA nucleotide has 16 possible chiral forms, but only one is useful in life. How were the other 15 excluded in prebiotic conditions? Also, the video does not mention the required activation of the nucleotides (i.e., providing them in a high energy, triphosphate form), nor their required maintenance, because activated nucleotides naturally decay. Science makes it clear that a high concentration of activated, homochiral free nucleotides can only occur in a contrived laboratory setting.

It then says: “Nucleotides automatically base pair with their partners on the existing chain.” The animation shows individual nucleotides matching up perfectly with the existing chain. This depiction overlooks two challenges. First, it does not show a primer — a matching segment of about 12 nucleotides of RNA that bonds to the template and helps start the process. Experimental approaches to replicating an RNA template make use of a primer, but how would a convenient primer segment of RNA be produced in a prebiotic world? And second, the convenient matching of individual base pairs “in cool water” is not realistic because aqueous solutions inhibit the formation of Watson-Crick bonds between individual nucleotides.2

“A Little Bit of Assistance” 

After the individual nucleotides match to the template, they must be chemically bonded to each other to form a complementary strand — and each bond must be at a consistent location between two nucleotides (i.e., a 3’ 5’ phosphodiester bond). Existing life performs this task with complex ligase enzymes, but such a process has no known prebiotic solution. Stated Clearly admits that this requires some assistance, specifically: “this is the part that currently requires assistance from researchers, we’re not yet sure how this would have happened in the wild.” However, admitting this limitation, and seemingly implying that it is the only remaining limitation, provides the false impression that they are candidly disclosing all limitations, thus deceptively winning the trust of the viewer. 

Next, “a complementary RNA strand is born. One with the exact inverse sequence of the original.” This suggests that the natural process has very high fidelity. In reality, all experiments to date have demonstrated insufficient fidelity to avoid “error catastrophe” — the complete loss of information over a series of generations.3 As origin-of-life researcher Gerald Joyce has concluded: “the fidelity of RNA polymerization should be considered a major impediment to the construction of a self-sustained, RNA-based evolving system.”4

According to the final statement: “If the water is then heated, paired bases lose their grip, allowing both chains to act as templates when the cycle repeats.” This also contradicts known science: “A second major problem with the chemical replication of RNA is that RNA duplexes > 20-30 nucleotides in length are difficult or impossible to denature thermally under template-copying conditions.”5 Although the animation depicts a shorter segment of RNA, specific function can only be achieved with RNAs longer than 20-30 nucleotides. Even if very high temperatures were successful in separating the two chains, they would likely recombine before any copying could occur, and the high temperatures would rapidly degrade the RNA.

Posing as Education

While posing as an educational video with scientific authority, this offering from Stated Clearly actually presents a tall tale while conveniently sweeping well-established science under the rug. Thus far, it has misled more than 720,000 viewers, in classrooms and elsewhere.

Coming up, I’ll examine another video from Jon Perry and Stated Clearly, “Can Science Explain the Origin of Life?

Notes

  1. The Murchison meteorite contained “tens of thousands of different molecular compositions, and likely millions of diverse structures,” which “suggests that the extraterrestrial chemodiversity is high compared to terrestrial relevant biological- and biogeochemical-driven chemical space.” Schmitt-Kopplin, P., et al., High molecular diversity of extraterrestrial organic matter in Murchison meteorite revealed forty years after its fall. Proc Natl Acad Sci USA. 2010; 107: 2763–2768. Also, see A. Wotos el al., Synthetic connectivity, emergence, and self-regeneration in the network of prebiotic chemistry. Science 2020; 369: 1584.
  2. “Even the impressive fidelity of the three hydrogen bonds in a single Watson-Crick GC nucleobase pair is insufficient to pay the cost of assembly and hydrogen bonds between individual nucleotides or nucleobases are not observed in aqueous solution until higher order oligomers are used (n ≥ 4).” Sawada T, Fujita M. A single Watson-Crick GC base pair in water: Aqueous hydrogen bonds in hydrophobic cavities. JACS 2010; 132: 7194-7201.
  3. Eigen, M. Self-organization of matter and evolution of biological macromolecules. Naturwissenschaften, 1971; 58: 465–523.
  4. Tjhung KF, Shokhirev MN, Horning DP, Joyce. An RNA polymerase ribozyme that synthesizes its own ancestor. PNAS 2020; 117: 2906-2913.
  5. Engelhart AE, Powner MW, Szostak JW. Functional RNAs exhibit tolerance for non-heritable 2′–5′ versus 3′–5′ backbone heterogeneity. Nature chemistry 2013; 5: 390-394.