Random mutations

I think part of the problem is that the article is somewhat misleading. This has to be an over generalisation. The mechanism of many induced and spontaneous mutations is already well established and there is no reason to assume that mutations which arise by these means need any specific 'evolved' mutational systems, for instance de-amination converting methyl-cytosine to thymine. No reason why it should. There are a number of proteins whose job it is to maintain accurate copies of genetic material since the processes of DNA replication are inherently proen to error. Why pre-suppose some ancestral perfect system of replication, especially since such a system would, as you note, effectively preclude evolution from occurring.It would only be true if mutation had to evolve, if mutation is a natural process mediated both by environmental factors and the mechanisms of genetic replication, then there is no problem with a continuously present rate of background mutation.That fact that evolving a mutator phenotype is good for bacteria doesn't mean that all mutation is due to evolved systems.TTFN,WK

But errors in replication are the fundamental tool needed to evolve. As long as you have a system which imperfectly replicates with heritable traits you should see some form of natural selection working to favour those traits which improve replication frequency.There is obviously a trade off between levels of mutation high enough to facilitate the occurrence of mutations with potentially beneficial phenotypes and levels so high that they destroy beneficial phenotypes. The fact that there are cellular systems for both error cheching and for inducing mutation show that evolution has acted to fine tune this balance to an acceptable level while still maintaining the potential for increased mutation in stressful environments.In pre-cellular life the most beneficial trait is simply going to be that of increasing the rate of , at least relatively true, replication.Simply by virtue of the way selection works those traits which allow both lots of replication and the maintenance of traits promoting replication are bound to be favoured. Many of those mechanisms are there as they are based on inherent chemical properties of genetic material. Certain mechanisms, such as the mutator system in that paper, will not be there, but mutation will still occur.TTFN,WK

Yes, it would have to have its origin from chemical reactions among components we would not consider to be alive. DNA and RNA can be chemically synthesised, but the processes as we use them are unlikely to bear much relation to their evolutionary origins. No, I don't neccessarily mean DNA. DNA is what most of the life we are familiar with happens to use at the present time, but there are compelling reasons to think that it was not the original form of replicating genetic information. Self-replicating RNAs would be another example or alternatively PNAs (Nelson, et al., 2000). The mechanisms would in many case already be there as they are simply chemical reactions affecting genetic material, they would be distinct from the mechanisms which initially synthesis that genetic material however in many cases. In the case of errors inherent in the replication of the genetic material they obviously would not have operated before self replicating material was available. So there is a plausible route for the synthesis of PNAs from pre-biotic chemicals. There is also considerable evidence that peptides and related forms, such as PNA or peptoids (Ghosh and Chmielewski, 2004). Nowhere really, Miller-Urey was the first proof of principle experiment showing the ability of particular elements important for life as we know it, in that case amino acids, from pre-biotic conditions. Given that the atmosphere used in M-U is no longer considered likely for he primitive Earth it is not directly relevant to the history of life on Earth, but it stil stands as a proof of concept.TTFN,WK

No, you are right. Tool is a bad term. What I usually use is substrate, as in 'Mutation introduces variation which acts as a substrate for natural selection'. Um, no. I would say almost certainly not, but feel free to provide some evidence if you feel that is the case. You mean apart from the many millions of instances of mutation as random as we are able to determine? There are hundreds of studies of point mutations and larger scale changes in bacterial clonal cultures, there are many studies of genetic mutations in children with spontaneous genetic defects.It is arguable that these are not truly random, in that not every mutation is equally likely to happen, but they are random in as much as there are many effectively random variables feeding into the processes of mutation. Because, as Mangy Tiger pointed out to you, the only thing it improves is replication frequency, which is what natural selection does naturally. It is simply a mathematical phenomenon. All else being equal something with a faster reproductive rate will come to predominate in a population. No. No, although many theistic evolutionists may choose to see RM/NS as a mechanism by which god can direct evolution. There is no reason why an omnipotent being couldn't cause a point mutation at just the right spot in the germ line of one organisms in order to establish a variant which will have an advantage in a different environment, something we would never be able to identify amongst the natural background noise of random mutations. That is the thing about being omnipotent you can do anything. That isn't a scenario one could ever disprove, which is why people who study evolution don't take it into consideration in the science they do, even if they happen to believe that is what is really happening.TTFN,WK

Yes. I think this could be very suggestive evidence for ID. The problem is one of defining 'pre-programmed'. Are we looking for something like a zipped file in the DNA? A short piece of sequence which some process will allow to be decompressed into a novel gene? Would you argue that the mechanism we see which act to direct hypermutation to some extent in response to environmental stress are 'pre-programmed'?I think that the first of these would clearly be suggestive, although not neccessarily conclusive, evidence for ID. The second I would argue could easily be brought about by natural selection. I can't think of any, but Ray seems to think there is a connection. It is true that there were some arguments when scientific estimates were first being proposed that some figures, in the hundreds of millions, were too short to allow for evolution to have occurred. However the current techniques for dating have absoloutely nothing to do with evolution and the assumptions behind those early estimates have been shown to be mistaken. No.TTFN,WK

There has in fact been some research already done into compressing DNA.
Compression is very different to decompression in this case however. The algorithms mainly work by reducing the space taken up by repeated sequences, this does not correspond to a way to get functional genomic information out of such simple repeat sequences.TTFN,WK

I thought it might be worthwhile bringing this thread back up. The current Great Debate between Faith and RobinRohan (with backing vocals by Pinksasquatch), 'Proofs of Evolution: A Mediocre Debate (Faith, robinrohan and their invitees) has touched upon non-random mutation, and I know it is a subject that Randman has brought up in passing several times. I thought it might be good to open up the discussion of this topic to the membership in general.TTFN,WKThis message has been edited by Wounded King, 22-Dec-2005 07:45 PM

That's certainly a reasonable philosophical argument, but what holds true as a requirement for evolution of nucleic acids need not hold true for anything else.Certainly perfection would suggest nothing more than stasis would be possible, there being no improvement possible. I believe they only suggest that if the designer is also supposed to be (omni)benevolent. Presumably such a benevolent designer would not produce circumstances in which the perfection he himself creates is going to lead to extinction and death.Such speculation however is not only off topic but entirely unamenable to scientific discussion.TTFN,WK