Message 1 of 52 (547754)
02-22-2010 9:52 AM
I found a fascinating (if shallow) article on "evolution in RNA chemicals" from various places I read RSS feeds from - in short, scientists have observed evolutionary traits in non-living chemicals.
The abstract is from http://www.cosmosmagazine.com/.../life-evolution-a-test-tube
An RNA enzyme that catalyzes the RNA-templated joining of RNA was converted to a format whereby two enzymes catalyze each other's synthesis from a total of four oligonucleotide substrates. These cross-replicating RNA enzymes undergo self-sustained exponential amplification in the absence of proteins or other biological materials. Amplification occurs with a doubling time of about 1 hour and can be continued indefinitely. Populations of various cross-replicating enzymes were constructed and allowed to compete for a common pool of substrates, during which recombinant replicators arose and grew to dominate the population. These replicating RNA enzymes can serve as an experimental model of a genetic system. Many such model systems could be constructed, allowing different selective outcomes to be related to the underlying properties of the genetic system.
so, in short, they had these RNA molecules (which replicate imperfectly, such that random mutation would take place) compete for food (the substrate in the testtube) - those which were "more fit" would become more numerous by "eating" more of the substrate. When the substrate was exhausted, samples were taken and the experiment started again with a new substrate.
From the beginning until the end, the RNA molecules "evolved" through "natural selection" as natural mutations and the pressure to "survive" did pretty much exactly the same as has been theorized by Darwin and many others.
It's not quite abiogenesis and it's definitely not life, but it is showing something that looks a lot like it and is taken as pretty good proof of how it works as well as giving us a glimpse of how things could have been before chemistry became life.
This topic then is two-fold, as I'd like to know what everyone thinks of this article (and the actual paper!) from http://www.cosmosmagazine.com/.../life-evolution-a-test-tube AND what they think of the very first comment:
Hype+Buzz Words != Science
Hmmm... sounds fascinating, but reading between the lines, its not really clear what these scientists observed or accomplished beyond a specific type of chemical reaction.
What was the mechanism that allowed these molecules to grow in complexity? What "problems" are they solving? What is meant by complexity? These words are so incredibly ambiguous and overloaded that without very clear definitions and specifics, I remain skeptical.
Submitted by Visitor on 21 February 2010 - 12:18pm.
because I think the very first comment is a religious nut. Why? Several reasons:
1) the first sentence makes out that the experiment didn't do anything (denial)
2) it talks about "a mechanism" for the chemicals to "grow in complexity" (sounds like "designer" to me)
3) it brings in the word "complexity", and then acts as if it's actually brought in by the article, and because it's "not defined" can be used to further denigrate the work
4) it calls the words "complexity" and "problems" as "ambiguous" and "overloaded" when these words weren't in the original article, yet still attempts to make it stick
5) it's quite obvious the reader didn't actually read the article because the commenter doesn't understand what happened (because point #4 is irrelevant)
All these add up to textbooks ignorant/conniving creationists (now, not all creationists are like this, but some most certainly are).
Am I wrong? why?
Edited by greyseal, : the extra abstract was added in explaining what was done, how and why.
Edited by Adminnemooseus, : Topic title changed from pretty worthless "To catch a creationist..." to "Self-sustained Replication of an RNA Enzyme", which is the title of the paper cited in message 4.