The Nylon Bug

The Nylon Bug

Comments by Lee Spetner, November 19, 2002

It's interesting, first of all, that the URL you pointed to picked the "nylon bug" as an example of a random mutation yielding a gain of information. (The short answer is, the mutation does yield an increase of information, but was it random?) It's interesting because the "nylon bug" is exactly what I used in my letter #7 to Jim Crow (of which you got a copy) as a possible example of a nonrandom mutation triggered by the environment. To respond to your query, I shall have to elaborate on this more than I did in that letter, which was not polemical.

Let me point out two important facts that the URL ignores. First, there are two altered enzymes, not just one. Both these enzymes are needed to metabolize the 6-aminohexanoic-acid-cyclic-dimer (6-AHA CD) found in the waste water of the nylon factory. Neither of these enzymes alone is effective. Both are needed. The first enzyme, which I shall call enzyme 1, is 6-aminohexanoic-acid-cyclic-dimer hydrolase (6-AHA CDH) and catalyzes the conversion of 6-AHA CD to 6-aminohexanoic-acid-oligomer (6-AHA LO). The second enzyme, which I shall call enzyme 2, is (6-aminohexanoic-acid-oligomer hydrolase (6-AHA LOH) and catalyzes the conversion of 6-AHA LO to 6-amino-hexanoic acid [Kinoshita et al. 1981]. Only enzyme 2 is the product of a frame shift. Enzyme 1, whose DNA sequence I have not seen, is probably the product of only point mutations. [Okada et al. 1983, Ohno 1984]

Second, enzyme 2 is not just the product of a frame shift, it is also the product of 140 point mutations. Many of these mutations are silent, but many are not. 47 amino acids out of 392 of the enzyme have been changed.

It seems to me that many of these altered amino acids are essential to the catalytic effect of the enzyme. How many, I don't know. In my above cited letter to Jim, I calculated the probability of getting multiple random mutations in the 30 years it took to evolve these enzymes. If the evolution of this enzyme had to rely on random point mutations, it could have never evolved. Thus, if only 6 of these 47 mutations were essential for the evolution, the probability of achieving it in 30 years is about 3 x 1035. So, if the evolution could not be random, then it would have to be nonrandom, and as I have suggested in my book, they would be triggered by the environment. That is, the capability is built into the bacterium and the environment triggers the mutations.

I have ignored the evolution of enzyme 1, and the random evolution of that enzyme makes for an even less probable event.

Now, why should there be a built-in capability to metabolize nylon, which did not exist until 1937 or so? The answer is there shouldn't be. But there could have been a built-in capability to metabolize some other substrate. Kinoshita et al. (1981) tested enzyme 2 against 50 possible substrates and found no activity, but that does not mean that it doesn't have activity on some substrate not tested. The activity of enzyme 2 was small, but enabled the bacteria to metabolize the nylon waste.

References

Kinoshita, S., T. Terada, T. Taniguchi, Y. Takene, S. Masuda, N. Matsunaga, & H. Okada (1981)) Purification and characterization of 6-aminohexanoic-acid-oligomer hydrolase of flavobacterium sp. K172. Eur. J. Biochem. 116: 547-551

Ohno, Susumu. (1984). Birth of a unique enzyme from an alternative reading frame of the pre-existed, internally repetitious coding sequence Proceedings National Academy of Sciences, USA 81: 2421-2425

Okada, H., S. Negoro, H. Kimura, & S. Nakamura, (1983) Evolutionary adaptation of plasmid-encoded enzymes for degrading nylon oligomers. Nature 306: 203-206.

At http://www.nmsr.org/nylon.htm Dave Thomas claims that the "nylon bug" is an example of random mutation leading to an increase of information. I asked Dr Lee Spetner for his opinion on this. Update, October 27, 2004: In my experience, Darwinists reply to Michael Behe's irreducible complexity criticism by postulating that there exists a large library* of dormant genetic material that can be checked out and expressed as needed. If this were true, it would demolish all Dave Thomas's nylon bug arguments, and all similar claims that examples have shown that random mutations plus selection, etc., have actually added information to organisms. *e.g., Finding Darwin's God", by Kenneth R. Miller (Cliff St. Books, 1999). p. 157: the current blood clotting system..."evolved from genes and proteins that originally served different purposes." *Darwinism Defended by Michael Ruse (Reading: Addison-Wesley, 1982), p.94: "there are usually masses of variation held in any natural population, and that selection can get to work whenever the case arises. It is not necessary to wait for the appropriate new mutation."	Arthur S. Lodge \| home The Nylon Bug \| Nylon Bug 2. Thomas on Spetner \| Nylon Bug 3. Spetner on Thomas Evolution Industrial Melanism Darwinism's Debit Sheet: 23 items
	The Nylon Bug Comments by Lee Spetner, November 19, 2002 It's interesting, first of all, that the URL you pointed to picked the "nylon bug" as an example of a random mutation yielding a gain of information. (The short answer is, the mutation does yield an increase of information, but was it random?) It's interesting because the "nylon bug" is exactly what I used in my letter #7 to Jim Crow (of which you got a copy) as a possible example of a nonrandom mutation triggered by the environment. To respond to your query, I shall have to elaborate on this more than I did in that letter, which was not polemical. Let me point out two important facts that the URL ignores. First, there are two altered enzymes, not just one. Both these enzymes are needed to metabolize the 6-aminohexanoic-acid-cyclic-dimer (6-AHA CD) found in the waste water of the nylon factory. Neither of these enzymes alone is effective. Both are needed. The first enzyme, which I shall call enzyme 1, is 6-aminohexanoic-acid-cyclic-dimer hydrolase (6-AHA CDH) and catalyzes the conversion of 6-AHA CD to 6-aminohexanoic-acid-oligomer (6-AHA LO). The second enzyme, which I shall call enzyme 2, is (6-aminohexanoic-acid-oligomer hydrolase (6-AHA LOH) and catalyzes the conversion of 6-AHA LO to 6-amino-hexanoic acid [Kinoshita et al. 1981]. Only enzyme 2 is the product of a frame shift. Enzyme 1, whose DNA sequence I have not seen, is probably the product of only point mutations. [Okada et al. 1983, Ohno 1984] Second, enzyme 2 is not just the product of a frame shift, it is also the product of 140 point mutations. Many of these mutations are silent, but many are not. 47 amino acids out of 392 of the enzyme have been changed. It seems to me that many of these altered amino acids are essential to the catalytic effect of the enzyme. How many, I don't know. In my above cited letter to Jim, I calculated the probability of getting multiple random mutations in the 30 years it took to evolve these enzymes. If the evolution of this enzyme had to rely on random point mutations, it could have never evolved. Thus, if only 6 of these 47 mutations were essential for the evolution, the probability of achieving it in 30 years is about 3 x 1035. So, if the evolution could not be random, then it would have to be nonrandom, and as I have suggested in my book, they would be triggered by the environment. That is, the capability is built into the bacterium and the environment triggers the mutations. I have ignored the evolution of enzyme 1, and the random evolution of that enzyme makes for an even less probable event. Now, why should there be a built-in capability to metabolize nylon, which did not exist until 1937 or so? The answer is there shouldn't be. But there could have been a built-in capability to metabolize some other substrate. Kinoshita et al. (1981) tested enzyme 2 against 50 possible substrates and found no activity, but that does not mean that it doesn't have activity on some substrate not tested. The activity of enzyme 2 was small, but enabled the bacteria to metabolize the nylon waste. References Kinoshita, S., T. Terada, T. Taniguchi, Y. Takene, S. Masuda, N. Matsunaga, & H. Okada (1981)) Purification and characterization of 6-aminohexanoic-acid-oligomer hydrolase of flavobacterium sp. K172. Eur. J. Biochem. 116: 547-551 Ohno, Susumu. (1984). Birth of a unique enzyme from an alternative reading frame of the pre-existed, internally repetitious coding sequence Proceedings National Academy of Sciences, USA 81: 2421-2425 Okada, H., S. Negoro, H. Kimura, & S. Nakamura, (1983) Evolutionary adaptation of plasmid-encoded enzymes for degrading nylon oligomers. Nature 306: 203-206.