tag:blogger.com,1999:blog-37148773.post5742263139911020249..comments2024-03-19T00:24:23.577-04:00Comments on <center>Sandwalk</center>: Flunking the Behe challenge!Larry Moranhttp://www.blogger.com/profile/05756598746605455848noreply@blogger.comBlogger109125tag:blogger.com,1999:blog-37148773.post-68030975021190191542015-07-15T10:12:33.943-04:002015-07-15T10:12:33.943-04:00Why is it important to discuss biology with someon...Why is it important to discuss biology with someone that thinks alchemy is a hot topic for a chemistry class?<br /><br />I think the real Behe challenge would be to prevent Mssr Behe's contribution to history from being a funny story teachers tell their students in the near future.<br /><br />Still its immortality of sorts I suppose...Anonymoushttps://www.blogger.com/profile/06845012149335070036noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-34989176552039470242014-08-27T13:32:02.621-04:002014-08-27T13:32:02.621-04:00Allan:
Heh. I didn't think you would be. But ...Allan:<br /><br /><i>Heh. I didn't think you would be. But you haven't even addressed them. You might as well just stick your tongue out!</i><br /><br />Funny, Allan, from my perspective it looks like all you've done is stick your fingers into your ears.Lino Di Ischiahttps://www.blogger.com/profile/00904662370561530557noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-11654901214871584712014-08-27T13:30:19.829-04:002014-08-27T13:30:19.829-04:00Diogenes:
Hilariously, Lino invokes the "Why...Diogenes:<br /><br /><i>Hilariously, Lino invokes the "Why don't chimps give birth to humans?" argument, one of the dumbest in all the arsenal of creationism:</i><br /><br />You've completely missed the point I was making. You have things backwards.Lino Di Ischiahttps://www.blogger.com/profile/00904662370561530557noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-4645246974351795682014-08-19T19:13:21.342-04:002014-08-19T19:13:21.342-04:00Not sure about the spy thriller, at some level you...Not sure about the spy thriller, at some level you have to be able to sympathize with the protagonist and that would be quite a stretch with Wells.steve oberskihttps://www.blogger.com/profile/14067724166134333068noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-46005256217377971142014-08-19T16:55:33.753-04:002014-08-19T16:55:33.753-04:00(continuing)
Of those many beneficial double muta...(continuing) <br />Of those many beneficial double mutations that have happened in human history, most got lost. We have to take population genetics into account. When we do that, we don't want to frame this in terms of a double-mutation, as if we have to wait for two mutations to happen in one individual. Actually, a mutation could happen in an individual, and the second in the individual's grand-child, even if the first mutation is deleterious (because low-fitness individuals have children and grand-children, just not quite as many as high-fitness ones). If we extend out this line of thinking, the probabilities start to add up, and we discover an important population-genetic phenomenon of "stochastic tunneling", where we can get from 0 --> 1 --> 2, even when 1 is deleterious and never takes over the population. <br /><br />And I know this because population geneticists have already looked at this question in some ways, and it is interesting. It is reasonable to ask how adaptations that require multiple mutations can emerge in evolution, and whether we can calculate any limits to that. I think the most general work is Lynch's paper, which cites Behe (http://mbe.oxfordjournals.org/content/27/6/1404.full.pdf+html ). <br /><br />So, we want to reframe this problem in terms of what Lynch calls "complex adaptations," i.e., adaptations that depend on multiple mutations, without restricting it to waiting for a double mutation. Complex adaptations are going to be more likely with more time, and less obviously, with larger population sizes (see Lynch). Humans are at a disadvantage relative to mosquitos and fruitflies and E. coli. At the end of the day, there are going to be some kinds of complex adaptations that are likely in fruitflies but negligible in humans. <br /><br />And basic models of this are available in Lynch's paper. This covers the case where the mutations are beneficial together and deleterious (or neutral) separately, and it also considers mutator alleles, and > 2 mutations. Arlinhttps://www.blogger.com/profile/03243864308260498878noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-84802356161631096992014-08-19T16:42:26.886-04:002014-08-19T16:42:26.886-04:00Much of this discussion doesn't focus on what&...Much of this discussion doesn't focus on what's important. Yes, there are a lot of mistakes in Behe's argument, but the general direction of it is interesting. We can grant Behe that a mutation might occur with a rate of 1E-10, even if he estimates this in the wrong way. Yes, Behe's implicit assumption that there is only one way to generate resistance is illegitimate, but we can still use this as an example. <br /><br />Behe’s calculation includes a number of mistakes, but we can ignore all but two of them. <br /><br />The larger of the two problems is that Behe makes an estimate for the rate of evolution of 1 complex adaptation in mosquito, and jumps from that to a conclusion about ANY complex adaptation in humans. This is like assuming that over the past million years, the only possible way for humans to adapt by a double mutation would be a specific pair of mutations like the ones in chloroquine resistance. <br /><br />That's not the right way to do it. Once we know how many possible mutations there are, we'll want to take that number and calculate the number of unique pairs, which is X(X-1)/2. Then we'll need to make a wild guess about what fraction are beneficial. I'm going to guess 1 in 1000 (but I'll also calculate assuming 1 in a million). <br /><br />Now, let's work the numbers. <br /><br />In the human genome, there are 2E9 bp, and for each one we could count 7 point mutations (3 substitutions, 1 deletion, 4 insertions-- of which 1/4 are redundant). There are lots of other types of mutations, and the numbers get really huge. The number of sequences of length i is 4^i, thus the number of possible de novo insertions is 4^i * n, where n is the genome size, which is ~ 1E6n for i = 10. A translocation has a point of origin chosen from the length of the genome, it extends up to r bp, and has a point of insertion chosen from the genome, so the count of translocations scales with rn^2! That's insanely large! Maybe we don't want to count these if we think they occur at rates much less than 1E-10 each. But we need to include at least 1.4E10 point mutations. <br /><br />The number of double-mutant combinations is then 1.4E10 * (1.4E10 - 1)/2 ~ 1E20. If we assume that 1 in a thousand combinations is beneficial, then we have to count 1E17 (and if we assume 1 in a million, that's 1E14). <br /><br />Thus, we have 1E17 (or 1E14) *beneficial* combos each with a rate of 1E-20, so the total rate per person generation is 1E-3 or 1E-6. In other words, you might have already met someone with a beneficial double mutation. This may seem counterintuitive, but look at it this way. Humans have a mutation rate such that the total genomic rate is about 1 (1.6 according to Drake, et al 1998). There are 0s, 1s, 2s etc in that distribution. You have some double-mutants in your family already. We just assumed that 1 in 1000 (or 1 in a million) are beneficial, so voila! multiple beneficial double mutants just in NYC.<br /><br />What about all of human evolution? If humans had a population size of a million for the past million years, that is ~1E11 person-generations, as a rough order-of-magnitude estimate. That's surely an over-estimate. With these numbers, humans have experienced many beneficial double mutations. Even if we assume that only 1 in a million doubles are beneficial, we still get about 1E5 of them in the course of human evolution. <br /><br />That solves the biggest problem with Behe's argument. The next problem, still quite significant, is the lack of population genetics. This post is long so I'll address that separately Arlinhttps://www.blogger.com/profile/03243864308260498878noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-39417780163328532712014-08-19T11:27:51.471-04:002014-08-19T11:27:51.471-04:00Can you explain in layman's terms how you can ...Can you explain in layman's terms how you can use Borel's theorem to make any event improbably?Devinhttps://www.blogger.com/profile/12511286189866238296noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-52837609593834808752014-08-18T02:53:26.606-04:002014-08-18T02:53:26.606-04:00It's a good plot for an academic spy thriller:...It's a good plot for an academic spy thriller: "The mole that came out of the hole: The wasted life of Jonathan Wells" Piotr Gąsiorowskihttps://www.blogger.com/profile/06339278493073512102noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-60806659410327416092014-08-17T19:25:44.218-04:002014-08-17T19:25:44.218-04:00Lino, like many creationists, attempts to wear us ...Lino, like many creationists, attempts to wear us down by sheer repetition. Behe said that protein binding sites can never evolve. We have counted numerous examples of protein binding sites evolving-- in Vpu in HIV and Vpr in HIV-2, snake venoms, affinity maturation in the immune system, bovine seminal ribonuclease, etc. etc., we piled them up, so Behe was wrong although IDcreationists change the subject when we list counter-examples. <br /><br />Behe said that malaria CR required two simultaneous mutations and it would take 10^20 parasites to evolve CR, and that this was applicable to all protein binding sites. The first two mutations in CR were sequential, not simultaneous, so Behe was wrong. It does not take anywhere near 10^20 organisms to evolve those two mutations, so Behe was wrong by a factor of about 10^5 according to my calculations which are more detailed than Behe's or Larry's. Behe never gave any reason why all protein binding sites should work like CR, and we know experimentally that many evolved and still evolve more quickly with fewer changes.<br /><br />Behe was proven wrong, experimentally and mathematically, on every every point. The IDcreationist response is to keep repeating and repeating falsehoods in the hopes of exhausting us.Diogeneshttps://www.blogger.com/profile/15551943619872944637noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-52316670308236118232014-08-17T19:04:05.640-04:002014-08-17T19:04:05.640-04:00I'm not persuaded by your arguments.
Heh. I d...<i>I'm not persuaded by your arguments.</i><br /><br />Heh. I didn't think you would be. But you haven't even addressed them. You might as well just stick your tongue out!<br /><br /><i>I think what Behe has pointed out is critical, and should be accepted as the starting point for a new understanding of life's diversity.</i><br /><br />Accepted by whom? It's full of holes, as several have tried to explain, and biologists will not accept it as a starting point for anything until those holes are addressed, not simply wafted aside. There is, as yet, no sound reason to suppose that a single example of a double mutation in an organism with a particular (and somewhat unrepresentative) life cycle can give us any guidance as to the capacity of evolution to explain organic diversity without the import of a Mysterious Tinkerer. AllanMillerhttps://www.blogger.com/profile/05955231828424156641noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-67249770546787679982014-08-17T12:36:12.257-04:002014-08-17T12:36:12.257-04:00Exactly. One can, after the fact, 'calculate&...Exactly. One can, after the fact, 'calculate' nearly any event into the realm of impossibility (by the common application - incorrect application, as I have been told - of Borel's theorem), as I easily did for a creationist's very existence a few years ago. He dismissed my calculations, but could not explain why Behe's or any similar anti-evolution probability calculations merit.nmanninghttps://www.blogger.com/profile/14767343547942014627noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-70600305161018875412014-08-17T12:15:16.955-04:002014-08-17T12:15:16.955-04:00Allan:
I'm not persuaded by your arguments. ...Allan:<br /><br />I'm not persuaded by your arguments. I think what Behe has pointed out is critical, and should be accepted as the starting point for a new understanding of life's diversity. It would be a shame if, with a outpouring of language, the really essential is made blind to the scientific eye.Lino Di Ischiahttps://www.blogger.com/profile/00904662370561530557noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-10768289941366450832014-08-17T11:37:44.323-04:002014-08-17T11:37:44.323-04:00Case in point:
Wells said that "destroying D...Case in point:<br /><br /><i>Wells said that "destroying Darwinism" was his motive for studying Christian theology at Yale and going on to seek his second PhD at Berkeley, studying biology and in particular embryology:<br /><br /><br /> <b>Father's [Rev. Moon's] words, my studies, and my prayers convinced me that I should devote my life to destroying Darwinism, just as many of my fellow Unificationists had already devoted their lives to destroying Marxism. When Father chose me (along with about a dozen other seminary graduates) to enter a Ph.D. program in 1978, I welcomed the opportunity to prepare myself for battle.</b></i><br />steve oberskihttps://www.blogger.com/profile/14067724166134333068noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-84729647481921652042014-08-17T10:12:19.257-04:002014-08-17T10:12:19.257-04:00Lino
But the entire discussion here is one where ...Lino<br /><br /><i>But the entire discussion here is one where I assume that the Darwinists want to "limit" the possibilities of the parasite so as to better explain the very limited extent of its final adaptation.</i><br /><br />The 'Darwinists' should, I hope, wish to be scrupulous about including ALL the factors involved. <br /><br />If recombination makes chloroquine resistance more likely, and yet it's still rare, this doesn't invalidate the other points made - the stochastic nature of occurrence, the inevitable excess of occurrence over detection, the possibility of unknown selective effects on the single mutants. The OP was about the many difficulties in making the calculation. But the discussion also brings out the difficulty of extrapolating from a single case to the whole of evolution. It certainly makes no sense to extrapolate from a model that ignores recombination to infer limits on sexual species. <br /><br />My ulterior reason for bringing in recombination is its impact on the dimensionality of the <i>genome-wide</i> probing of genetic space. No organism is subject to a single threat at a time. Recombination brings together combinations involving just about every gene in the population. If you focus on a single pairing - say CR's double mutation - you may puzzle as to why it hasn't arisen, given that its likelihood is only increased by recombination. But there are thousands of genes in the genome, and novel pairings arise all the time. While you're sitting staring at CR and wondering why it is so rare, thousands of gene combinations are occurring and being subject to the environmental experiment of Natural Selection. Once again, the 'birthday paradox' rears its head. The chance of NO advantageous combinations is exponentially reduced with each additional candidate. And it's that that Behe is trying to argue for from this single instance - CR is rare, therefore this is the limit on evolution. It's a linear extrapolation. But - to the extent that it is a limit, which isn't very much - it is a limit on the <i>single case</i>. Satisfying yourself that <i>multiple genes in multiple genomes in multiple species</i> are subject to this limit is an error in handling probabilities.AllanMillerhttps://www.blogger.com/profile/05955231828424156641noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-19050058452823905672014-08-17T02:37:58.042-04:002014-08-17T02:37:58.042-04:00Steve, an education in a subject is not the same a...Steve, an education in a subject is not the same as learning about it for the express purpose of attacking it. Jonathan Wells and his writings on junk DNA are the perfect example.Paul McBridehttps://www.blogger.com/profile/09953009288824698018noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-8428963030359782772014-08-16T22:43:53.103-04:002014-08-16T22:43:53.103-04:00Hilariously, Lino invokes the "Why don't ...Hilariously, Lino invokes the "Why don't chimps give birth to humans?" argument, one of the dumbest in all the arsenal of creationism:<br /><br /><i>"if you say that "no" 'two-step' changes need take place, then, given enough time, there is NOTHING preventing a chimp from becoming a gorilla, or a human to start becoming a chimp."</i><br /><br />This bears no resemblance to evolutionary theory. To which I reply: if your God is real, there's nothing to prevent him from turning humans into chimps.<br />Diogeneshttps://www.blogger.com/profile/15551943619872944637noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-29824644008013859362014-08-16T21:46:22.917-04:002014-08-16T21:46:22.917-04:00Hey Steve,
What's next, images of the virgin ...Hey Steve,<br /><br />What's next, images of the virgin mary in <a href="http://carbolicsmoke.com/2010/06/15/bp-miracle-clean-up-workers-report-seeing-numerous-images-of-virgin-mary-other-religious-figures-in-oil-slick/" rel="nofollow">random oil slicks</a> and grilled cheese sandwiches and jesus in <a href="http://www.huffingtonpost.com/2013/06/13/dog-butt-looks-like-jesus-photo_n_3436086.html" rel="nofollow">dog's assholes</a> ?<br />steve oberskihttps://www.blogger.com/profile/14067724166134333068noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-58091318750829725032014-08-16T21:40:44.963-04:002014-08-16T21:40:44.963-04:00Lino says:
"But the entire discussion here is...Lino says:<br />"But the entire discussion here is one where I assume that the Darwinists want to "limit" the possibilities of the parasite so as to better explain the very limited extent of its final adaptation.<br /><br />What am I missing here?"<br /><br />You're missing a lot, aaparently. No one is trying to 'limit the possibilities of the parasite'. Quite the contrary, as I mentioned above, many of the limitations you are talking about undermine Behe's calculation. The 'very limited extent' of malaria's adaptation is an assumption og Behe that has zero evidence to support it.<br /><br />We have been trying to explain it to you in so many different ways here, that you should not be asking us what you are missing. You should be asking yourself.Chris Bhttps://www.blogger.com/profile/04778164246719803780noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-52952959531762025052014-08-16T16:38:22.924-04:002014-08-16T16:38:22.924-04:00Steve: "two powerball wins in two draws sugge...Steve: <i>"two powerball wins in two draws suggests that Powerball was designed with this knowledge in mind"</i><br /><br />Nothing analogous to this has ever happened in the history of evolution.<br /><br /><i>"Evolution required an endless string of Powerball wins. Intelligence makes that happen."</i><br /><br />What a non sequitur! Powerball wins happen once a week, and it's due to sheer randomness. Maybe Steve had something else in mind, but if he's going to blurt analogies he should think up better ones.Diogeneshttps://www.blogger.com/profile/15551943619872944637noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-76159667929975175842014-08-16T16:33:29.658-04:002014-08-16T16:33:29.658-04:00Lino says: And now Summers' paper demonstrates...Lino says: <i>And now Summers' paper demonstrates that CR is NOT POSSIBLE without AT LEAST TWO SPECIFIC MUTATIONS! ...This paper CONFIRMS Behe's surmise that the malarial parasite, because of the difficulty it has in developing CR is required to "find" TWO mutations, not just ONE. This has now been demonstrated.<br /><br />Behe was right. The Darwinists were wrong. Do we hear any apologies?"</i><br /><br />Behe should apologize for being dead wrong about this, and everything else he's ever said. <b>No scientist said CR resistance required one mutation! Absurd.</b> The scientists arguing with Behe said it might require two or three or four-- the actual number is four-- and if single mutants were neutral, or slightly deleterious, they could be sequential. <b>Behe said it was two and they had to be simultaneous</b> which means each single mutant had to be lethal. <br /><br />He said simultaneous. The mutations were sequential. Behe was wrong, again. Behe also said no protein binding sites had ever evolved nor could evolve because functional sites require multiple simultaneous mutations; and he was immediately smacked down by <a href="http://endogenousretrovirus.blogspot.com/2007/08/michael-behe-please-allow-me-to.html" rel="nofollow">ERV who pointed out that Vpu evolved a protein-protein binding site</a>, plus it's a gated cation channel and it evolved a Golgi-binding targeting sequence. Scientists piled up <a href="http://pandasthumb.org/archives/2007/11/an-open-letter-4.html" rel="nofollow">example after example of newly evolved protein binding sites.</a> Then there was <a href="http://pandasthumb.org/archives/2008/04/behe-versus-rib.html" rel="nofollow">bovine seminal ribonuclease evolving a protein binding site</a> by changing a single amino acid, and the examples compiled by Grueninger et al. There was the alanine scanning mutagenesis work of James Wells in the 1990's, and affinity maturation of antibodies in the immune system.<br /><br />Molecular biologists know how easily functional sites evolve, and they have no reaction to Behe's work except to feel douche chills as he face-plants himself over and over.Diogeneshttps://www.blogger.com/profile/15551943619872944637noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-90233414712182502192014-08-16T16:19:34.624-04:002014-08-16T16:19:34.624-04:00I mangled the last sentence in the third paragraph...I mangled the last sentence in the third paragraph. It should read:<br /><br /><i>Per what we see happening in the malarial parasite, any change to the chimp genome that required not 'one' step, but 'two' steps (i.e., two mutations" occurring in one organism in the population at the same time) then not even ONE such change has occurred.</i><br /><br />BTW, if you say that "no" 'two-step' changes need take place, then, given enough time, there is NOTHING preventing a chimp from becoming a gorilla, or a human to start becoming a chimp.<br /><br />I don't know about you, but I don't see anything like that happening.Lino Di Ischiahttps://www.blogger.com/profile/00904662370561530557noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-87877435917153088142014-08-16T16:15:38.710-04:002014-08-16T16:15:38.710-04:00Mikkel Rasmussen:
Yes, you're probably right....Mikkel Rasmussen:<br /><br />Yes, you're probably right. I made a very quick calculation in my head---but the calculation is meant for effect, not to form the basis of some study of mammalian lineages.<br /><br />Why don't we take chimps. Six million years ago, it is thought that the split between chimps and humans took place.<br /><br />Well, let's say that population of chimps world-wide, at the time, was one million. Let's say that population size was maintained for the intervening six million years. That's six trillion replications. Per what we see happening in the malarial parasite, any change to the chimp genome that required not 'one' step, but 'two' steps (mutations" occuring in one organism in the population at the same time, then not even ONE such change has occurred.<br /><br />These kinds of numbers make neo-Darwinism look wholly inadequate.<br /><br />Part of the discussion of Behe's work should include the mathematical model that he and Snoke developed. The model predicted that huge numbers of generations would be needed for even minor changes to the genome.<br /><br />They laughed at his work. But, of course, laughing is not refuting.<br /><br />Nevertheless, Behe then looked for real-life confirmation of the numbers his model had generated. He looked to the malarial parasite because it was so well-known and studied, and, the selective advantage was as favorable as NS could give you.<br /><br />And the numbers show that only mild changes occur. Almost next to nothing. And, of course, think of smaller populations of animals throughout the world. How did these possibly evolve?<br /><br />He was laughed at again. Told he didn't know what he was talking about.<br /><br />And now Summers' paper demonstrates that CR is NOT POSSIBLE without AT LEAST TWO SPECIFIC MUTATIONS! The purpose of the 'caps' is to help you to 'focus like a laser' on the true issue at hand. This paper CONFIRMS Behe's surmise that the malarial parasite, because of the difficulty it has in developing CR is required to "find" TWO mutations, not just ONE. This has now been demonstrated.<br /><br />Behe was right. The Darwinists were wrong. Do we hear any apologies?<br /><br />No.<br /><br />Do we see people changing their views? No.<br />Do we see people changing their minds? NO.<br /><br />The LHC smashed protons together at such high energies that they could explore particles of very high energy=very high mass. String Theory posits particles of very high mass, so high, in fact, that we hadn't discovered them before the LHC got up to its high energies. But now, even at these high energies, or, equivalently, these high masses, no new particles have been detected.<br /><br />Now, the scientific approach would be to say that theory has been severely undermined. Instead---in the field of physics, not biology---in a field that lends itself to exactitude, excuses are now being offered as to why these particles were not detected. <br /><br />Eventually, the string theorists will have to give up. And so, too, the Darwinists.<br /><br />Behe, per the Darwinian imagination, should not have come up with the numbers and findings that he did. Instead of changing your views, you heap scorn on the "messenger."<br /><br />Alas.<br /><br />No one has said anything here that takes away from the import ofLino Di Ischiahttps://www.blogger.com/profile/00904662370561530557noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-51295861221506961032014-08-16T15:53:39.606-04:002014-08-16T15:53:39.606-04:00It seems to me what you're saying is that the ...It seems to me what you're saying is that the malarial parasite, because of its short period of existence within the mosquito where it can there reproduce sexually, now has an even greater chance to explore the possibilities available to it in finding a way to resist the deadly effects of chloroquine.<br /><br />But the entire discussion here is one where I assume that the Darwinists want to "limit" the possibilities of the parasite so as to better explain the very limited extent of its final adaptation.<br /><br />What am I missing here?Lino Di Ischiahttps://www.blogger.com/profile/00904662370561530557noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-77251105976162741132014-08-16T13:01:01.237-04:002014-08-16T13:01:01.237-04:00I don't understand your dismissal. Yes, of cou...I don't understand your dismissal. Yes, of course recombination increases the chances. My whole point. I gave a numerical example, showing that recombination/syngamy only has to happen infrequently to have a substantial effect on the probabilities - in the example, it was a million times more effective than serial mutation at generating a particular double mutant from the same starting population. You can pick other figures to give lower differentials, but recombination nearly always wins. It is much more powerful, therefore you can't just ignore it when calculating the probability of a particular combination. <br /><br /><i>But if the probabilities are increased---and let's assume slightly---then the numbers we're dealing with only become stronger in pointing out the limited space of possibilities that neo-Darwinian mechanisms can explore.</i><br /><br />How does its contribution to raising the likelihood constitute an even greater <i>limit</i> on 'neo-Darwinian' mechanisms? <i>ad absurdum</i>, if the likelihood was zero, there would be no limit on the capacity of 'neo-Darwinian' mechanisms! Nah. Syngamy and Recombination make evolution happen faster and allow much more broad probing of the space of possibilities than serial mutation alone. That's why Life went a bit wild after 2 billion years of asexual stasis. AllanMillerhttps://www.blogger.com/profile/05955231828424156641noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-89227874650768082262014-08-16T11:49:10.413-04:002014-08-16T11:49:10.413-04:00Allan:
Thanks for the illustration. However, I t...Allan:<br /><br />Thanks for the illustration. However, I think your explanation is simply along the lines I suspected, and that is that the likelihood of arriving at the needed 'combination' of mutations is, if anything, increased by recombination. But if the probabilities are increased---and let's assume slightly---then the numbers we're dealing with only become stronger in pointing out the limited space of possibilities that neo-Darwinian mechanisms can explore.<br /><br />That's what I see you saying here:<i>But there are many intervening asexual generations, taking place in a milieu which, if it includes chloroquine, will give these genome frequencies a significant boost from selection. It is no longer drift alone that causes increase in frequency. And each increase exponentially increases the likelihood of a successful combination.</i><br /><br />And that's what I had in mind when I said, "How does recombination change the results of Summers' paper and the numbers we have from White?" I should have probably said, "How does this <i>appreciably change</i> the results of Summer's paper and the numbers we have from White?"Lino Di Ischiahttps://www.blogger.com/profile/00904662370561530557noreply@blogger.com