An early release of this week's journal Science is reporting that a Ph.D. student at Scripps Institute has created RNA enzymes that are capable of self-replicating and, when placed into tubes with other, though dissimilar RNA enzymes, the enzymes were able to borrow functional elements from other enzymes and, in doing so, evolve. The process in the experiment continued until the most fit replicators dominated the population. Here is the story from Fox http://www.foxnews.com/story/0,2933,479777,00.html Podcast: http://www.npr.org/templates/player...ion=1&t=1&islist=false&id=99132608&m=99135715 The journal article (subscription required): http://www.sciencemag.org/cgi/content/short/323/5911/198
There is a popular idea among molecular biologists that RNA predated DNA. If that is the case, then there would have had to be ribozymes capable of catalyzing their own synthesis. This experiment has show that this hypothesis is possible. This is big in the field of evolutionary and molecular biology.
Kind of makes you think that this stuff, has to be spread all around our Galaxy as well as the rest of the Universe...specially when the Universe is an estimated 14 Billion years old...
Speculate about what? That the molecules are "alive"? If you haven't heard the podcast, I recommend that you do. The student's major professor's comments may surprise you.
I think there may be misunderstanding Celt, my contention is it is a wholly fabricated experiment, in a lab, with a design, what I'd like to see is more exploration around the deep sea volcanic vents for the most basic life forms studied. The article plainly states this experiment did not produce "life", we both can agree on that one.
I agree with that thought brother but I think this is a very valuable experiment because it shows that it is possible to have self-replicating ribozymes and that is important to support at least the idea of a RNA first world. It is also interesting to note that the researchers had no expectation that the molecules would replicate or, even less so, that they would evolve. That was a surprise to the student and the PI. This is really no different than early experiments that answered the question about whether adaptation was driven or random. Before you can bark up the proverbial tree, it is always easier if you know which tree was amicable to barking.
The problem with a whole cloth experiment is the conditions are controlled as much as possible, to me that sort of ruins the impact of the knowledge gained. Here is an example of what I mean: http://www.physorg.com/news145602862.html A scientist once explained to me the problem with using a data point, then extrapolating out results, one "fact" does not mean the rest follow. Alas though Bro Celt, I'm not a Chemist, not even so much as a the most basic organic chemistry involving activated tin foil and ma huang..
I have too much other stuff that I need to read tonight so I won't have time to read the journalistic article you posted but I will try to read it this weekend. When you are considering a difficult question such as "How do microbes evolve?". You consider all the possible ways. Two prominent ones that come to mind are 1) organisms evolve because the environment forces a choice between evolving to overcome the environmental stress or extinction or 2) the adaptation happens independent of the environmental change and is therefore random. Given those hypothesis, it would not be sound to propose a grant without first having some preliminary data to act as a guide. You can't go to NIH or NSF and ask them for millions of dollars to fully explore both possibilities. Agreed? In the case I mentioned, bacteria growing on agar plates were replica plated onto agar plates that has been supplemented with low inhibitory concentrations of an antibiotic known to kill E. coli. Low and behold, some of the colonies transfered to the antibiotic plate survived and their clones also survived when grown on antibiotic plates. Did the bacteria survive because some colonies were able to rapidly adapt to the lower concentrations of the antibiotic? It turned out that when the researchers went back to the original plate and flooded that plate with high concentrations of the same antibiotic, the same colonies that survived on the replica plate also survived on the original plate. That experiment pointed towards one of the two hypothesis being more credible and now the researchers were to go forward to request grants to answer questions about random gene mutations. You have to propose an idea and show that what you propose is reasonable. I am sure that your scientist friend would not disagree with that. In order to continue to explore the question of RNA first, the researchers had to show that they could make the precursors using the same building blocks and energy that was available in the primitive atmosphere and environs. It was only luck or providence that the molecules that resulted were able to self - replicate.
