Hi RAZD and CTD

RAZD said, correctly, that we can watch, count and measure mutations. There are obviously limits to how closely we can watch but we can indeed watch these changes. Those bacterial experiments I explained earlier are a prime example where only one DNA strand was present at the initiation of the experiments yet we can now count mutations (as any variation from that original DNA pattern is a mutation) and we can observe their effects. We can even go so far in these experiments as to track the protein changes and the metabolic pathways created in great detail to know that evolution in these organisms is indeed inventive and produces beneficial changes in these organisms as we watch.

From this one set of experiments we can see deleterious mutations that lead some colonies to extinction, we can see beneficial mutations that lead some colonies to increased fitness and we see many changes that have no detectable effect on the organisms. We also know, due to the nature of Codon encryption, that many changes are silent as they don’t change the protein which the gene codes for in any way. Outside coding regions this is less certain as some non coding DNA sequences have been shown to have a regulatory effect on genes around them.

I didn’t see anywhere where RAZD said that we could count every single mutation. That is not true as we would have to sequence every single individuals DNA and even then we’d miss the mutations that occur during the lifetime of the individual to non germ line cells. Wild studies that track the genetics of every single member of a population are being done in a number of in the wild studies today but I’m not aware of any results coming in yet. Such a venture is very expensive and time consuming though the results should be facinating.

This seems to be a big deal for you CTD so lets ask what would be the effect on evolution if it were true that there was no such thing as a neutral mutation. Would that destroy ToE? Not at all. All that this discovery would do, much as the vestigial organs arguments do, is to refine our understanding of how the process works. For evolution to work there has to be some beneficial mutations, that’s it. If you could show that there were no beneficial mutations, ever, you would have disproven ToE.

Vestigial organs are very interesting and much misunderstood by creationists in particular and many others in general. A vestigial organ in evolutionary terms is not an organ with no current function, if it had no function today it would probably have disappeared altogether or would at least be in the process of doing so. The correct definition of a vestigial organ is one that has lost its primary function. The appendix is an organ used for cellulose fermentation in the vast majority of creatures who possess one and, in creatures who actually use it, it contains a high concentration of cellulose digesting bacteria. It is in effect a bacterial nursery. In humans it has lost this previously primary function. Like most organs the appendix housed more than one function but in humans at least its primary function is no longer necessary and the organ has shrunk significantly as a result. That is the definition today of vestigial.

R2 omits to mention that DNA can be read more than once. It is sometimes read forwards, then again backwards and/or skipping every so many letters.

I omitted to mention many things that may in time come to be relevant to this discussion. I’m not writing a text book on the subject here. When such things are relevant I’ll discuss them. How is any of that relevant to what I said? Does it change the understanding I have presented in any way?

And the only way for a typo to fail to degrade a text is if an optional letter or a placeholder is involved. For example, potatoe can lose the e on the end and still be potato. Both spellings are correct. Also, a partially degraded text can be read sometimes, but further deterioration will make it useless.

Yes I understood already CTD that you don’t know how DNA works so let’s look at how it actually works. It’s not a language like English so your analogy fails. If you wanted to write Leucine (a protein base) in DNA you could write UUA or UUG or CUU or CUC or CUA or CUG for instance. Now obviously any mutation that changes one of those codes say corrupting UUA to UUG would be silent and so Neutral as they both spell Leucine. There are some exceptions in which DNA is read frame shifted but as transcription always begins at a start Codon AUG in diploid species this is not normally the case at least for humans and other animals. There are a very few exceptions in non diploid species in which transcription may start at other locations without mutations. These do make true silent mutations rarer for some organisms but, as I said, that doesn’t apply to humans, it doesn’t apply to any diploid species that I am aware of.

And the fact remains: not all functions of any given stretch of DNA code are known.

That’s true, for non coding DNA, DNA that does not contain start/stop codons and so does not get transcribed into mRNA. Some such DNA stretches have been shown to have regulatory functions so it’s not easy to determine if a given stretch of DNA has no function though much of it does not appear to. Knockout experiments have shown that perfectly healthy organisms can be created with some large stretches of ‘silent’ DNA removed so that’s at least suggestive that it lacks function.

In Reason

Russell