Are mutations truly random or are they guided?

Except that the requisite cellular processes don't exist. How could they? These processes would have, in effect, to be able to think. The mechanisms in a bacterium, for example, would have to be able to look at the chemical structure of a novel antibiotic, look at the metabolism of the bacterium, and figure out what changes needed to be made to its genetic code to make its metabolism invulnerable to the antibiotic --- a question so difficult that no human geneticist would undertake to figure it out a priori. I would not completely rule out a scenario in which an organism had a mechanism for performing some specific act of genetic engineering on itself in response to long-standing fluctuations in the environment. But it is beyond belief that the cell could have a general mechanism for making appropriate changes to its genome.One point which has already been made is that most mutations are not particularly useful. Now you might suggest that only one cell in a million has the intelligence to figure out what the right mutation is, but it seems simpler to imagine that they all mutate at random and one cell in a million is lucky enough to get it right.(By analogy, the fact that some people win the lottery does not particularly persuade me that people have psychic powers allowing the winners to divine the correct numbers --- since dumb luck will in fact explain the frequency with which people win.) I would draw your attention to the existence of genetic algorithms and genetic programming. We know that these processes work, and we know exactly how these processes work, and there is not a chance that the random number generator of a computer somehow knows how to solve every problem that computer scientists throw at it. In this case we can be utterly certain that there's no intelligence in the mechanisms --- but the random variation is indeed sufficient.

Because it's a footnote. That's obviously not how most evolution works. But when we investigate such mechanisms they don't involve organisms doing genetic engineering on their germ cells. When I'm exposed to the sun, I tan, I don't change the DNA in my sperm to ensure that I have black children. Would it be too much to ask that an argument from incredulity directed against a quantitative proposition should involve some actual math?It turns out that the rate of mutation does account for the rate of evolution. I can show you some figures if you like. The fact that a cell is a fairly complex thing doesn't imply that it can perform intelligent acts of genetic engineering any more than it implies that it can write operettas. We know, after all, what the various bits of the cell do. They don't do that.

Amen.Now, if you don't mind, some of us are trying to discuss biology. We are aware of your halfwitted religious dogma, and if we were ever in danger of forgetting it, we could ask you to remind us of it.In the meantime could I point out that in the real world it is not a deficiency of a theory that it incorporates processes that are known for certain to happen.

All those that have in fact produced new systems or organs. Unless you think they were produced by magic ... oh, but wait, you do.Well, if you're going to hide from reality behind magical explanations, I don't see what one could say that will make you face the facts. Go play with your imaginary friend.

I think that "guided" is too strong a word. The effect discussed in the paper still doesn't allow the mechanism to "know" which mutations would be beneficial, just which genes might benefit from a mutation. (Of course, since we know from creationist dogma that their are No Beneficial Mutations, Amen, this is in fact a mechanism for royally screwing organisms up in the very locations where they are most vulnerable, as devised by a God who was either retarded or perversely vindictive.)Edited by Dr Adequate, : No reason given.

Yes, but if those processes existed they wouldn't be magical, would they?

But somehow can be proclaimed "deleterious" even though their effect is unmeasurable.

Firstly, slightly beneficial mutations are also near-neutral; secondly, neutral mutations are actually neutral. Slightly deleterious mutations are a proper subset of those which have little or no effect.Also, please bear in mind that Kimura doesn't rely on the mutations being near neutral rather than completely neutral. Rather, Kimura's theory can cope with near-neutral mutations. The closer they are to neutral, the more their long-term fate will be decided by drift rather than selection, so for sufficiently near-neutral mutations, selection can be overlooked for the sake of doing the math.(By analogy, I think you said you do physics. Remember how for the sake of the math, when analyzing the motion of a pendulum, you can take sin x ≈ x when x is small? It's like that.) But are there significantly more slightly deleterious mutations than slightly beneficial ones? I don't see how this estimate (unsupported, I note, by facts) is generous. Surely after all this time we must be very close to the equilibrium point at which the fixation of deleterious mutations by drift is balanced by the fixation of beneficial mutations by drift and selection?Edited by Dr Adequate, : No reason given.

There is a good explanation of why creationists manage to swindle dupes like you into thinking that they're good debaters, which is that none of their statements are constrained by reality. If you find it boring to have your biological illiteracy pointed out, then there are two solutions, both in your own hands. One is to acquire a little basic biological literacy, the other is to stop talking about biology. We can show you lots of random mutations, like all of them.Can you show me one instance of God poofing organisms out of nothing by magic? First, please tell us how we can determine a beneficial mutation which is a "starting point" from one which isn't. Thank you. Speak for yourself. I for one am not older than Young Earth Creationists are prepared to admit that the Earth is, and if I was I wouldn't have spent my whole life looking at bacteria. But this is not actually true. See Barry Hall's experiments, for example. Show your working. Oh, wait, you haven't done any, have you? You've just made stuff up.Which brings me back to my first point in this post. Creationists have lots of debating points which would be excellent if only they had any connection to reality or logic or math or the facts. The reason creationists can swindle people is that they address their balderdash to an audience too pig-ignorant of biology to notice that they base their case securely on stuff that they've made up in their heads.

Perhaps so, but it was one I didn't make.Still, it would do you no harm to familiarize yourself with the basics. No time at all, since it was not what I actually wrote. You could have saved yourself some time by just typing: "I am angered by my own inability to formulate a rational response". That's not witty, that's just true. Well, next time you say something, perhaps you should try to work out in advance what it means. That is indeed biological naivety on a scale that surpasses the dreams of lesser creationists.You might as well think that since I believe that some babies grow up to be brain surgeons, I should know what such a baby looks like. Well, in a sense, I do --- small, baldish, wrinkled, goes waaah! a lot. Just like all the others. Yes. Pretty much all of them. Just as I could name lots of babies that COULD grow up to be brain surgeons.In reurn, could you point out one thing poofing into existence by magic which COULD be the result of divine fiat? The idea that you might one day learn something about biology seems to particularly distress you. Yes, it would put a crimp into your ability to be wrong. But as I can tell you from personal experience, being right has its pleasures too.Edited by Dr Adequate, : No reason given.

Yes, let's.I'll run over the major points. Point #1 : the mechanisms that you envisage do not exist. Yes, the cell is complicated, but scientists have given us a fairly good idea of what each bit of it does. We know what the ribosome does, we know what tRNA does, we know what aminoacyl tRNA synthetase does. Yes, the biological mechanisms are complicated, but biologists understand them. There is no mysterious mechanism left over which might do the thing that you envisage some cellular mechanism doing. Point #2 : the mechanisms that you envisage do not operate. If, for example, you expose bacteria to an antibiotic, then maybe one bacterium in a million will evolve resistance to that antibiotic. Now, if there was some smart mechanism for evolution hidden in the complexity of the cell, then they'd all do this. But they don't. It's a matter of dumb luck. Point #3 : The mechanisms that you envisage are unnecessary. Random variation plus selection does work. I referred you in my previous post to the success of genetic algorithms. I read recently that the boffins at Oak Ridge are using evolutionary methods to produce new designs of nuclear power plants. Are they crazy? No. It works. Random variation plus selection does solve problems. If you threw in your imaginary Lamarckist mechanisms, it might work faster. But boring old Darwinism works anyway. It's slow, but it gets there in the end. We don't need to postulate anything else to explain evolution --- it works just fine already.

"Hand waving", eh?Choose your words with more care. You wish to jump from the proposition that cells are complex to the existence of a cellular mechanism for which there is absolutely no evidence. That is hand-waving.Yes, cells are complicated. But that's no reason to suppose that they are capable of performing any particular complex task that you happen to dream up.