Summations Only

See here.Anything else I can help you with, Alan?

If you wish to say that evolution does not require all beneficial mutations to appear simultaneously, but that rather they can be accumulated by natural selection over many generations, then you could say so.Indeed, you don't really need to say that: we are familiar with the theory of evolution. Perhaps, then, you could simply proceed to whatever point it is you wish to make. Thank you.

Well, in fact it is possible for diseases to evolve resistance to combination therapies. It just takes a while. Here's one of the key papers in the development of combination therapy for HIV. Note that it says: Also, one can hardly take the evolution of resistance to combination therapy as a paradigm for evolution in general. In nature, most species are not being simultaneously assailed by three different poisons carefully designed and selected to fuck them up. If someone were to feed a population of humans on arsenic, cyanide and thallium then the population would not evolve resistance (because of going extinct) but this sheds little light on whether birds evolved from dinosaurs.Edited by Dr Adequate, : No reason given.Edited by Dr Adequate, : No reason given.Edited by Dr Adequate, : No reason given.

That's an interesting assertion. Do you have any evidence for it?

I note that your own paper says: "Recently, it has been seen that combination therapy for the treatment of malaria has failed to prevent the emergence of drug-resistant variants."Similarly, here's a paper on the evolution of resistance to combination therapy in HIV patients.So if you propose that there was some set of natural conditions, without planning and forethought, that somehow prevented dinosaurs from evolving into birds over millions of years --- with greater efficiency that we, with intelligence, forethought, and understanding of the underlying microbiology, can prevent the evolution of drug resistance in pathogens over mere decades ... well, that's not a proposition that anyone's going to swallow without a great deal of evidence for it; it seems intrinsically unlikely.

But to judge by the abstracts of those papers there is nothing in them which relates to the number of loci which must mutate simultaneously to convert a dinosaur into a bird. We would all concede that simultaneous adaptive mutation of loci is unlikely; the question is, can you prove that such a thing would be necessary to dinosaur-bird evolution?Edited by Dr Adequate, : No reason given.

But as you correctly point out in message 76, the evolution of three things doesn't have to be like winning three lotteries; it can be like one person winning a lottery, and then one of his descendants winning a lottery, and then one of his descendants winning a lottery. I think that nature isn't actually designed to thwart evolution, and so is likely to be even less successful at doing so than things which are.To return to dinosaurs and birds, I suppose you could look at it that way and say that there were some dinosaurs that were killed or impeded in replicating for want of being able to fly. That's hardly a reason why they should not have evolved flight, is it?Edited by Dr Adequate, : No reason given.

Is there some reason why the evolution of resistance in this case can't involve two or more sequential mutations? Well, the multiplication rule of probabilities would apply if, as you say, the mutations required for the evolution of birds had to happen simultaneously (or if some large number of them did). But do you have any evidence that this is the case?

It seems to me that you have only half an argument. On the one hand, you have seen the force of what Darwin said 150 years ago, that natura non facit saltus --- nature does not take leaps. So far we are in agreement. We can also agree why this is the case: because a simultaneous coordinated set of beneficial mutations is extraordinarily unlikely on statistical grounds. So far, so good.But then you add the proposition that the evolution of birds must have required such a leap. And this premise appears simply to have been plucked out of thin air.

But as we can see from the example of HIV and malaria, applying targeted selection pressures simultaneously also leads to the evolution of resistance. I mean simply that the combination therapies were designed, by us, to mess with the pathogens and indeed in particular to make it harder for them to evolve resistance. (And yet they still manage it!) Nature was, surely, not designed with the aim of thwarting evolution. No part of it is the result of a vast endeavor by teams of brilliant scientists determined to prevent dinosaurs from evolving flight. There are too many for them all to be transformed simultaneously, we can agree on that. If you wish to maintain that there are too many for them to have changed sequentially, over the course of millions of years, then please show your working.

Is that a no? I presumed that by "the multiplication rule" you meant that P(A & B) = P(A) * P(B) if the events are independent. Hence for example we can use this rule to calculate the probability of me throwing six on two dice. If instead I keep rolling one die until I get a six, and then keep rolling a second die until I get a six, that's a whole different question, and the probability of me getting two sixes is in fact 1. I arrived at that result without using the multiplication rule, and indeed without using multiplication. Well, it seems to me that you also said something about birds, and I wondered if you had any evidence for it.Edited by Dr Adequate, : No reason given.

Yes, many pressures are always acting on a population. Which, of course, weakens your point. A strain of bacteria evolving resistance to just one antibiotic does so in the teeth of a thousand selection pressures. Adding the antibiotic makes it a thousand and one.And still they evolve. Well, I was already aware of that stuff. What I am unaware of is any reason why this gives us a compelling argument against the evolution of birds. I don't have a description of the sequence of mutations which produced birds, which I why I have never claimed that I did and then gone on to adduce this as a proof of the evolution of birds. You, however, seemed to be claiming that you had a proof that no such pathway exists. If you don't, then this thread is about done.

Show your working? So, we'd need to know the number of beneficial mutations, the number of generations, and also, and this would be the really awkward bit, we'd need enough data to avoid the Sharpshooter Fallacy: what we need to know is not the probability of evolving the exact birds we have, but the probability that w'd be having this sort of conversation. But very little about birds. Well, if you have mathematical certainty, you must have some actual math. Perhaps you could demonstrate it using dinosaurs and birds as an example. To which the answer would be, "one locus at a time, over a long period".Let's have a look again at how fast HIV adapts to combination therapy, shall we? That's fast. It doesn't tell us much about dinosaurs, though, since on the one hand HIV has a higher mutation rate and population, and on the other hand the HIV is evolving to selection pressures specially designed and selected to be hard to adapt to. Still, this at least makes it look plausible that dinosaurs could evolve much more slowly than that and still produce feathers etc, since they do have an awfully long time to do it in.Edited by Dr Adequate, : No reason given.

Well, they are, as I pointed out; it's just that most of these are conservative. As would of course be the case with dinosaurs.But to even start applying this to dinosaurs we'd need to know how many beneficial mutations get your from dinosaurs to birds and how long it took. But examples of something else. In order to do the working in the dinosaur-to-bird case, we'd need to know these things about dinosaurs and birds. How many beneficial mutations? How many generations? What mutation rate? What is the strength of the selection pressures? Which operated concurrently and which consecutively? How many other evolutionary pathways would have struck us as equally remarkable? Right, but in order to do the math we need the actual data.By analogy, the formula area = width height works the same for all rectangles, but in order to apply it to any particular rectangle we would need to know the particular width and height.If we were to assume that birds evolved as fast as HIV does, then you, Kleinman, wouldn't have a leg to stand on. But we know that they don't. So in order for us to figure out how much water your argument holds, it's kind of important to have some actual data about birds. Well, everything that's different about the two cases makes a difference. Though I seem to remember that HIV is diploid and undergoes recombination. Once again --- I don't go about telling people that I've found such an evolutionary pathway. You, on the other hand, claim to have a proof that there is no such pathway. That's for you to demonstrate.(What on earth you mean by "targeted" in this context I cannot begin to imagine, perhaps you could explain?) And yet as I have pointed out, everything is subject to multiple simultaneous selection pressures, yet and many things do in fact evolve efficiently. This empirical observation beats your "mathematical lesson" (which does not appear to involve any mathematics).Edited by Dr Adequate, : No reason given.Edited by Dr Adequate, : No reason given.Edited by Dr Adequate, : No reason given.

Yes. If you could manage to prove that the Earth isn't old, that would be a much more effective answer to evolution than anything you've shown us so far. You would need to start a new thread so as not to annoy the moderators.