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To: gobucks
Read the article and found it silly. Some bacteria can digest nylon, which is synthetic so there are 3 possible explanations for this and scientists "prefer" the third one (that a nylon eating gene recently evolved) for some very unconvincing reasons. The other argument against intelligent design was (I kid you not) that it is "boring" because it would answer everything.

The above is not science. It is the religion of science.

Even if bacteria can evolve a gene to digest nylon, that does not disprove intelligent design. Such a capability is an intelligent design, but scientists have no idea that such a gene evolved. They admit they just "prefer" that explanation. It seems to me that ID is the "why" behind everything that scientists usually say is none of their business.

14 posted on 09/28/2005 6:44:58 AM PDT by Williams
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To: Williams

After I finished reading the article, I totally shared your reaction ... esp about the nylon part.

The fact that the I.D. efforts (assuming that it is pure nonsense, which I don't) can provoke this kind of inanity at the very minimum indicates just how weak the position of Darwinism is...


17 posted on 09/28/2005 6:50:12 AM PDT by gobucks (http://oncampus.richmond.edu/academics/classics/students/Ribeiro/Laocoon.htm)
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To: Williams

Here is William Dembski's response regarding the so called "Nylon Bug" as evidence of Random Mutation plus Natural Selection creating complexity :

http://www.uncommondescent.com/index.php/archives/348#more-348




The problem with this argument is that Miller fails to show that the construction/evolution of nylonase from its precursor actually requires CSI at all. As I develop the concept, CSI requires a certain threshold of complexity to be achieved (500 bits, as I argue in my book No Free Lunch). It’s not at all clear that this threshold is achieved here (certainly Miller doesn’t compute the relevant numbers). Nor is it clear that in the evolution of nylonase that anything like pure neo-Darwinism was operating. Instead, we see something much more like what James Shapiro describes as “natural genetic engineering” (go here). And how do systems that do their own genetic engineering arise? According to Shapiro, Darwinism (whether neo or otherwise) offers no insight here.

Let’s look at nylonase a bit more closely. Nylonase appears to have arisen from a frame-shift in another protein. Even so, it seems to be special in certain ways. For example, the DNA sequence that got frame-shifted is a very repetitive sequence. Yet the number of bases repeated is not a multiple of 3 (in this case, 10 bases are probably the repeating unit).

What this means is that the original protein consisted of repeats of these 10 bases, and since it is not a multiple of 3, it means that these 10 bases were translated in all three possible reading frames (the second repeat was one base offset for translation relative to the first repeat, and the next was offset one more base, etc). Moreover, none of those reading frames gave rise to stop codons. Since the 10-base repeat was translatable in any reading frame without causing any stop codons, the sequence was able to undergo an insertion which could alter the reading frame without prematurely terminating the protein.

Actually, the mutation did cause a stop codon; but the stop codon was due not to frame shift but to the sequence introduced by the inserted nucleotide. Simultaneously, the mutation introduced a start codon in a different reading frame, which now encoded an entirely new sequence of amino acids. This is the key aspect of the sequence. It had this special property that it could tolerate any frame shift due to the repetitive nature of the original DNA sequence. Normally in biology, a frame shift causes a stop codon and either truncation of the protein (due to the premature stop codon) or destruction of the abberant mRNA by the nonsense-mediated decay pathway. Nonetheless, the nylonase enzyme, once it arose, had no stop codons so it was able to make a novel, functional protein.

Most proteins cannot do this. For instance, most genes in the nematode have stop codons if they are frame-shifted. This special repetitive nature of protein-coding DNA sequences seems really rare; one biologist with whom I’ve discussed the matter has never seen another example like it. Maybe it’s more common in bacteria. Thus, contrary to Miller, the nylonase enzyme seems “pre-designed” in the sense that the original DNA sequence was preadapted for frame-shift mutations to occur without destroying the protein-coding potential of the original gene. Indeed, this protein sequence seems designed to be specifically adaptable to novel functions.

There is something very special about the nylonase host gene that isn’t true of most genes in general and gives it much greater evolvability. As an aside, the function of the original gene (before it mutated into a nylonase) appears unknown (I’d be grateful for any insight here). The original paper suggested that the host gene was unlikely to encode a functional enzyme on account of lacking the amino acids normally found in active enzymes, so maybe it played some structural role that was not critical for the cell (no mention was made whether the host gene was a duplicate).

Here is a reference to the original paper: “Birth of a unique enzyme from an alternative reading frame of the
pre-existed, internally repetitious coding sequence”, Susumu Ohno, Proc. Natl. Acad. Sci. USA, Vol. 81, pp. 2421-2425, April 1984.

OHNO ON-LINE:
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=345072

COMPLETE PDF:
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=345072&action=stream&blobtype=pdf


51 posted on 09/28/2005 7:22:21 AM PDT by SirLinksalot
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To: Williams
Read the article and found it silly. Some bacteria can digest nylon, which is synthetic so there are 3 possible explanations for this and scientists "prefer" the third one (that a nylon eating gene recently evolved) for some very unconvincing reasons. The other argument against intelligent design was (I kid you not) that it is "boring" because it would answer everything.

Seems to me that there is a missing possibility. The "nylonase" gene could exist because it served another purpose -- maybe to break down something that was similar to nylon.

101 posted on 09/28/2005 9:03:49 AM PDT by Celtjew Libertarian (Shake Hands with the Serpent: Poetry by Charles Lipsig aka Celtjew http://books.lulu.com/lipsig)
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To: Williams
Read the article and found it silly. Some bacteria can digest nylon, which is synthetic so there are 3 possible explanations for this and scientists "prefer" the third one (that a nylon eating gene recently evolved) for some very unconvincing reasons.

But for the Creationist, all evidence and reason that would tend to support evolution will be "very unconvincing," right? Why are the non-evolutionary explanations to be considered plausible? If the nylonase gene was in the bacteria all along, why is it not expressed in proteins? And if the DNA coding the nylonase was created by an Intelligent Designer, either at the Time Of Creation or in the very recent past, why is the nylonase enzyme only 2% as efficient as the original

An explanation from natural selection is that the mutated DNA producing nylonase has not had time to undergo the additional mutation and selection pressure to achieve a more affect nylon degrading enzyme.

A good discussion by Dave Thomas at New Mexicans for Science and Reason:

My favorite example of a mutation producing new information involves a Japanese bacterium that suffered a frame shift mutation that just happened to allow it to metabolize nylon waste. The new enzymes are very inefficient (having only 2% of the efficiency of the regular enzymes), but do afford the bacteria a whole new ecological niche. They don't work at all on the bacterium's original food - carbohydrates. And this type of mutation has even happened more than once!

246 posted on 09/28/2005 9:27:51 PM PDT by MRMEAN (Suppose you were an idiot, and suppose you were a member of congress;but I repeat myself. Mark Twain)
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