November 4, 2012 | David F. Coppedge

Two Houdini Escapes in Origin-of-Life Speculations

Serious challenges to naturalistic origin of life theories (OOL) are wiggled out of magically in two pro-evolution articles.

The Challenge of Error Catastrophe

Survival of the Cooperationist:  On New Scientist, Bob Holmes acknowledge the problem of “error catastrophe” (complete genomic breakdown due to inaccurate copying), but then wiggled out of it by speculating that “First life may have survived by cooperating.”  Here’s the challenge:

The earliest life may have been a primordial soup of RNA molecules, but the first crude self-replicating molecules in this “RNA world” would have faced a big problem. They had to grow to store more information, but that made copying errors more likely. Get big enough and these errors become almost certain, destroying the molecule’s information.

The solution, Holmes said, is divide and conquer: “In theory, the first replicators could have avoided this ‘error catastrophe’ by splitting their information between several cooperating molecules,” he continued.  “Then the network could function as long as copies of each molecule survived.”

This seems to be a blatant case of the Personification Fallacy, but Holmes defended it by pointing to an experiment at Portland State where Niles Lehman got 3 molecules together, with A repairing B, B repairing C, and C repairing A.  “When they pitted the cooperative network against a selfish, self-repairing molecule, the cooperators won out,” he said, continuing the personification.  Gerald Joyce commented favorably on the speculation.  Another researcher got higher yield by forcing ribozymes to cooperate in non-biological chemicals that concentrated them.

Holmes did not comment on whether these two experiments were intelligently designed.

The Challenge of Compartmentalization

Grab the chemicals off the shelf:  OK, so one gets impersonal molecules to “cooperate” by division of labor, where they all help repair one another’s mistakes.  But how do you get them in the same space?  They’re not going to cooperate for long if they drift apart.  They need a membrane, a proto-cell, to stay together.  In “Early-Earth cells modeled to show how first life forms might have packaged RNA,” PhysOrg elaborates on the experiment mentioned above where Penn State researchers forced ribozymes into an artifical membrane composed of dextran in polyethylene glycol (PEG).  “These solutions form distinct polymer-rich aqueous compartments, into which molecules like RNA can become locally concentrated,” Christine Keating explained.  Nice.  But how do they get their food?  That question was overlooked.  Instead, Keating gave an imaginary leap back billions of years ago with the power of suggestion:

Keating added that, although the team members do not suggest that PEG and dextran were the specific polymers present on the early Earth, they provide a clue to a plausible route to compartmentalization—phase separation. “Phase separation occurs when different types of polymers are present in solution at relatively high concentrations. Instead of mixing, the sample separates to form two distinct liquids, similar to how oil and water separate.” Keating explained. “The aqueous-phase compartments we manufactured using dextran and PEG can drive biochemical reactions by increasing local reactant concentrations. So, it’s possible that some other sorts of polymers might have been the molecules that drove compartmentalization on the early Earth.”

Sure, anything’s possible.  She didn’t name the candidate polymers, nor explain how the two distinct types of polymers associated.  Maybe they needed a compartment around them, too.  She also didn’t explain how ingredients get in or out.  Passive diffusion is no help; it can’t differentiate between helpful and harmful molecules.  Cells have complex membrane machines that provide active transport, bringing the good stuff in and keeping the nasty stuff out.  Without active transport, a compartment is little more than a death trap (1/17/2002 commentary, 4/11/2006, and Jack Szostak’s creative solution, 1/14/2009).

Let’s get this straight: an improbable membrane forces selfish RNA molecules together, turning them into cooperating networks that help each other avoid error catastrophe.  Problem: the cell can’t divide, because there isn’t any genetic code yet to provide accurate cell division.  So either the cell dies, or inaccurate division occurs: helper A and B split up into another dextran bubble, while helper C is left alone to die.  Result: error catastrophe.  Lehman imagines RNA molecules wanting to help each other correct errors.  How do they know (or care about) the difference between an error and a correction on another molecule?  Remember, they’re selfish!   OOL is cool when you don’t think about it.

There are so many other problems we don’t have time to get into: the challenge of getting left-handed proteins and right-handed nucleotides by chance (see online book), the challenge of migrating from RNA to DNA, the challenge of metabolism, etc. (search the Origin of Life category for many, many more).  Any scenario that glosses over these major difficulties commits the fallacy of glittering generalities.

Anything is possible when speculation is allowed into the science lab (12/22/2003 commentary).  That’s why taking away the magic wand from the Darwin Party is essential to sound science.  We’re not interested in your imagination, Darwinists: PROVE IT.

 

 

(Visited 29 times, 1 visits today)

Comments

  • John_Michael says:

    An article I like over at ICR has the title of,
    Evolution Hopes You Don’t Know Chemistry: The Problem with Chirality
    by Charles McCombs, Ph.D.

    Design, purpose and information.
    It’s the essence of life!

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.