Are Fitness Valleys Too Deep?

_{June 30, 2011

Intelligent Design}

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Over at PhysOrg.com, there’s a new news item about a computer program that was run simulating evolutionary characteristics. What’s interesting about it are two things: (1) who the people are that are running this program, and (2) one of the results—which is being downplayed, it would seem.

First, one of the people associated with this new program is Christoph Adami, who, with others, gave us the touted “Avida” evolutionary algorithm. So, this isn’t just anybody doing this simulation.

Second, here’s what the lead author had to say:
“These fitness landscapes simply could not be traversed with mutations that did not interact.”

This wasn’t a ‘main conclusion’ of the study; however, I don’t know about you, but this sounds to me like any ‘single’ mutation cannot get you across any fitness valley, and, therefore, seems to rule out having a single mutation ‘sweep’ across a population to fixation.

IOW, without epistatic effects, evolution cannot move forward. This is unexpected. It makes simple neo-Darwinian evolution that more complex with more hurdles to get over. And, it is another nail in the coffin of neo-Darwinism. That is: “Another day, another bad day for Darwinism.”

Comments

Elizabeth, I hope comment #41 explains it already. In case it does not, basically, by the resources I mean time and the initial pool of genes (initial diversity, initial information). By the chasms I mean chaos. In biology chaos essentially means death or deleterious mutations. I can refer you to Stuart Kauffman "Antichaos and Adaptation", Sci. American, 1991, pp.78-84. The paper is available online (you can find a link to it on Wikipedia). I am not a biologist, I have an engineering background which allows me to doubt the plausibility of macroevolution, esp. in light of the works of Behe, Axe (esp. the one where he showed tight limits on the number of deleterios mutations possible in bacteria), Gauger and others in biology and information theoretic work of Dembski. My thoughts laid out in detail can be found here: http://orthodoxchristian-blogger.blogspot.com/2011_03_01_archive.html I am citing all the mentioned works there.Eugene S_{July 1, 2011
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junkdnaforlife @35: That is all fine with the exception of practical bounds on time and other resources available at time 0. In my opinion, this reasoning fits only microevolution. In other words, I am happy with the random mutation + natural selection scenario starting off in an initial state with some already existing forms. It could have been plausible on a greater scale (to allow for new species or higher taxinomic ranks), if it had been practically possible. Practical research shows insurmountable difficulties for macroevolution.Eugene S_{July 1, 2011
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Eugene S:
Fintess is understood as the degree of adaptation to the environment. I do not see any problem with this.
Excellent :)
One of the inherent problems of Darwinism in my opinion is not here but in the curse of dimensionality: the probabilistic resources of the world seemingly are not enough to explain the diversity of life.
What does that have to do with "dimensionality"? We know that there are countless dimensions along which populations can evolve (size, camouflage, predictive ability, toxicity, energy efficiency, as well as feedback loops that involve evolution along such odd dimensions as "a more spectacular tail"). What resources do you consider limit these dimensions?
Stuart Kauffman talks about coevolving landscapes, i.e. he hypothesises that as time progresses the landscapes change,
Yes indeed. Sexual dimorphism is a good example of this.
but that is too much to accept at such a grand scale.
Why?
Microevolution is observed and consequently I can accept Kauffman’s theory of antichaos, but only to the extent of microevolution (microadaptations of available forms). You cannot get over the chasms of chaos and preserve life.
Why not? Are you sure? Which chasms are you thinking of?
There are other practical limits to macroevolution such as the number of mutations of paralogous genes.
Why is there a practical limit to the number of mutations of paralogous genes?Elizabeth Liddle_{July 1, 2011
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Joseph @2: Fintess is understood as the degree of adaptation to the environment. I do not see any problem with this. One of the inherent problems of Darwinism in my opinion is not here but in the curse of dimensionality: the probabilistic resources of the world seemingly are not enough to explain the diversity of life. Stuart Kauffman talks about coevolving landscapes, i.e. he hypothesises that as time progresses the landscapes change, but that is too much to accept at such a grand scale. Microevolution is observed and consequently I can accept Kauffman's theory of antichaos, but only to the extent of microevolution (microadaptations of available forms). You cannot get over the chasms of chaos and preserve life. There are other practical limits to macroevolution such as the number of mutations of paralogous genes.Eugene S_{July 1, 2011
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You mean explain what polymorphisms are? Or explain how they arise? I'll assume the latter and get back to you later. There are lots of known mechanisms.Elizabeth Liddle_{July 1, 2011
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Elizabeth Liddle:
Certainly some alleles do become fixed. But many (most?) genes have polymorphisms.
Ah. Thanks for reminding me. You've mentioned polymorphisms a number of times. Each time I've asked how you explain them.Mung_{June 30, 2011
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Elizabeth Liddle:
Yes, eventually some mutations do become fixed (as, interestingly, do some neutral mutations as well as slightly deleterious ones, but beneficial ones are more likely to go to fixation).
So, in addition to "beneficial" mutations sweeping through the population I should have said that "deleterious" and "neutral" mutations sweep through the population (but at lesser rates)? So, per this logic, Darwinian evolution depends on neutral (no selective value) and deleterious (negative selection factor) mutations. How does this help? Here's what the lead author wrote per William Roache: The process of acquiring beneficial mutations, many of which will add up in effect to cause a population of organisms to evolve, depends on a second factor – the process of natural selection.
A better mental picture of the neo-Darwinist (if I must use that term! Not sure I like it because I’m not anti-Margulis for instance) is of lots of nearly-neutral mutations occurring all the time i.e. new alleles appearing all the time, some of which result in a slightly fitter genotype, some a slightly less fit genotype, but, as I tried to convey in my response to Joseph above, the concept of fitness is always in relation to a single generation, and what is slightly beneficial in one generation may be slightly deleterious in another.
I suspected you would come up with Kimura's "Neutral Theory". But, Lizzie, the neutral theory is not Darwinian. Kimura invented the neutral theory because of the radical inadequacy of Darwinian (Modern Synthesis) theory to explain newly discovered rates of polymorphism, rates which were staggeringly higher than 'theory' predicted.
So the kind of “sweep” that occurs is not that a single mutation “sweeps” through the population, but that there are lots of different alleles, and that the frequency distribution of each allele changes from generation to generation, the ones that tended to be associated with more progeny increasing in frequency, and the ones that tended to be associated with fewer, reducing. And so the mean fitness of the population tends to optimise with the alleles that contribute to the most successful gene cocktails (aka genotypes) in that environment, at that time, becoming the most frequently. Over time, the least successful alleles may drop out of the gene pool altogether, and, if they are ever needed again, will have to mutate ab initio (which occasionally happens). But that isn’t “speciation” – that’s simply adaptation. Speciation happens when a population diverges for some reason, into two populations that don’t, or rarely interbreed, for example if they become separated by a mountain range, or a stretch of water. When that happens, adaptation continues, but the environmental history of the two populations will change – one side of the mountain may be drier than the other, or there may be different predators. And, because the two populations are now adapting independently to environmental changes, they will not only tend to differ from their ancestral populations, but also from each other, to the point where they could not interbreed even if the barrier between them was removed. And it is this divergent adaptation that we call “speciation”. Adaptation is what happens down a single lineage; speciation is the process by which one population lineage diverges into two.
So, based on this argument, FIRST,there are no differences between adaptation and speciation. SECOND, it is purely qualitative and, so, speculative. And, THIRD, where is Natural Selection mentioned in any of this?PaV_{June 30, 2011
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When the strawman tactics of Bjorn Ostman are striken, his argument settles back down to earth, to something actually debatable, that many find demonstrably lacking in certain aspects. Notice that the strawmen are loaded into the top, and bottom of the post, nicely insulating the actual argument. Quaintly tucking it away so that by the time you get to it, many of the laymen will have already concluded the he is the man of reason and his opponents are ignorant fanatics. Strawmen Strucketh: When creationists continue to reiterate that evolution is not happening, they are perpetuating some serious misunderstandings of the science involved. Either they honestly do not understand how these things work, or they are knowingly misrepresenting them for the laymen, and I don’t know which is worse. The arguments against evolution – obviously based on the faith that Genesis must be true, lest the Bible loses all relevance – are foolish inasmuch as they have been stated many times, but have all been countered by scientists. Some people of faith purposely elect to disregard these arguments, but hopefully other people are more willing to hear what the true workings of evolution are, as much as we know them at this time. ~~Among the most foolish ones is the argument that~~ biological complexity cannot increase by way of random changes in DNA. This is completely false, which is quite easily seen, ~~and yet the argument is continually cited in creationist literature (do a google news search for ‘evolution’).~~ This argument is made leaving out a crucial factor, namely natural selection. The argument goes that random changes (mutations in the genome/DNA) are most likely to have a deleterious effect on the organism, which will therefore die as a result, and no change in the genome will be perpetuated. For every beneficial mutation, there are many deleterious ones, and overall the effect of beneficial mutations will drown in the adverse effects of deleterious mutations. As a consequence, no new variation can evolve. Or so they say. But this is false, and there are no two ways about it. The process of acquiring beneficial mutations, many of which will add up in effect to cause a population of organisms to evolve, depends on a second factor – the process of natural selection. Not all the organisms are hit by deleterious mutations. Some are lucky enough to have beneficial mutations – random changes that happen to make them slightly better suited for reproduction. And exactly because they reproduce a little more than average, there will be a higher fraction of organism in the population with that particular change in their genome in the following generations. This is natural selection, and it precisely explains how complexity can increase by the process of random change. Natural selection transforms the random process of mutation into a deterministic process. The problem in this debate is of course that science claims as its domain anything that the scientific method can be applied to. This means there is an overlap with a literal reading of the Bible (specifically Genesis 1 and 2). Those who have the faith (i.e. a strong belief in God, which can be overcome by no amount of rationality) will of course not let this happen, and only because of this technicality do the creationists object in the first place. Not because they were doing science, which happened to show that evolution does not occur. They got the conclusion first, and have secondly gathered their so-called scientific evidence to arrive at this predetermined conclusion in numerous books and papers, and recently in a creationist museum. This debate so tedious, there is no denying that. But it will go as with Galileo and the heliocentric system: eventually everybody in their right mind will come around, and this will no longer be something sane people will spend any time debating any more. junkdnaforlife_{June 30, 2011
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Kairosfocus, actually a 'couple of galaxies away' is far too generous for it only takes into consideration a single protein fold,, whereas: The Case Against a Darwinian Origin of Protein Folds - Douglas Axe - 2010 Excerpt Pg. 11: "Based on analysis of the genomes of 447 bacterial species, the projected number of different domain structures per species averages 991. Comparing this to the number of pathways by which metabolic processes are carried out, which is around 263 for E. coli, provides a rough figure of three or four new domain folds being needed, on average, for every new metabolic pathway. In order to accomplish this successfully, an evolutionary search would need to be capable of locating sequences that amount to anything from one in 10^159 to one in 10^308 possibilities, something the neo-Darwinian model falls short of by a very wide margin." http://bio-complexity.org/ojs/index.php/main/article/view/BIO-C.2010.1 ,,, Kairos, the closest comparison I could find for putting any meaning to the number 1 in 10^159 is this; The Case for Jesus the Messiah — Incredible Prophecies that Prove God Exists By Dr. John Ankerberg, Dr. John Weldon, and Dr. Walter Kaiser, Jr. Excerpt: But, of course, there are many more than eight prophecies. In another calculation Stoner used 48 prophecies (even though he could have used 456) and arrived at the extremely conservative estimate that the probability of 48 prophecies being fulfilled in one person is one in 10^157. How large is the number 10^157? 10^157 contains 157 zeros! Let us try to illustrate this number using electrons. Electrons are very small objects. They are smaller than atoms. It would take 2.5 times 10^15 of them, laid side by side, to make one inch. Even if we counted four electrons every second and counted day and night, it would still take us 19 million years just to count a line of electrons one inch long. But how many electrons would it take if we were dealing with 10^157 electrons? Imagine building a solid ball of electrons that would extend in all directions from the earth a length of 6 billion light years. The distance in miles of just one light year is 6.4 trillion miles. That would be a big ball! But not big enough to measure 10^157 electrons. In order to do that, you must take that big ball of electrons reaching the length of 6 billion light years long in all directions and multiply it by 6 x 10^28! How big is that? It’s the length of the space required to store trillions and trillions and trillions of the same gigantic balls and more. In fact, the space required to store all of these balls combined together would just start to “scratch the surface” of the number of electrons we would need to really accurately speak about 10^157. But assuming you have some idea of the number of electrons we are talking about, now imagine marking just one of those electrons in that huge number. Stir them all up. Then appoint one person to travel in a rocket for as long as he wants, anywhere he wants to go. Tell him to stop and segment a part of space, then take a high-powered microscope and find that one marked electron in that segment. What do you think his chances of being successful would be? It would be one in 10^157. Remember, this number represents the chance of only 48 prophecies coming true in one person (there are 456 total prophecies concerning Jesus). http://www.johnankerberg.org/Articles/ATRJ/proof/ATRJ1103PDF/ATRJ1103-3.pdfbornagain77_{June 30, 2011
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El, shoot let's really expand the research and see what evolution can do for the biggest 'worldwide' experiments that can be performed:L "The likelihood of developing two binding sites in a protein complex would be the square of the probability of developing one: a double CCC (chloroquine complexity cluster), 10^20 times 10^20, which is 10^40. There have likely been fewer than 10^40 cells in the entire world in the past 4 billion years, so the odds are against a single event of this variety (just 2 binding sites being generated by accident) in the history of life. It is biologically unreasonable." Michael J. Behe PhD. (from page 146 of his book "Edge of Evolution") Nature Paper,, Finds Darwinian Processes Lacking - Michael Behe - Oct. 2009 Excerpt: Now, thanks to the work of Bridgham et al (2009), even such apparently minor switches in structure and function (of a protein to its supposed ancestral form) are shown to be quite problematic. It seems Darwinian processes can’t manage to do even as much as I had thought. (which was 1 in 10^40 for just 2 binding sites) http://www.evolutionnews.org/2009/10/nature_paper_finally_reaches_t.html The Sheer Lack Of Evidence For Macro Evolution - William Lane Craig - video http://www.metacafe.com/watch/4023134bornagain77_{June 30, 2011
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Mung:
So what then is a beneficial mutation? How do we tell?
Excellent question. The short answer: we can't easily, we can only infer, statistically, that there must be a distribution from very beneficial to very deleterious. But near neutrality you can't tell which is which, and of course most mutations are near neutrality. The only method I know of to do it unambiguously is Lenski's with E-coli, because not only does he have lots of lineages from a single ancestral population, but he can actually thaw out clones from that ancestral population and compare each lineage with its forebears. Other than that, linkage studies are the only way I know.Elizabeth Liddle_{June 30, 2011
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El,, 'No, of course not. However, I would point out (AGAIN!) that a “beneficial” means “in relation to the current environment.' Of course you mean that for you have no evidence of 'beneficial' in regards to actually building functional complexity!!!!bornagain77_{June 30, 2011
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El, 'Yes, eventually some mutations do become fixed (as, interestingly, do some neutral mutations as well as slightly deleterious ones, but beneficial ones are more likely to go to fixation).' and yet in the real world we have,,,: spectacularly) - October 2010 Excerpt: "Despite decades of sustained selection in relatively small, sexually reproducing laboratory populations, selection did not lead to the fixation of newly arising unconditionally advantageous alleles.,,, "This research really upends the dominant paradigm about how species evolve," said ecology and evolutionary biology professor Anthony Long, the primary investigator. http://www.arn.org/blogs/index.php/literature/2010/10/07/experimental_evolution_in_fruit_fliesbornagain77_{June 30, 2011
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Mung:
Elizabeth Liddle:
I would like to know where PaV got the idea that the above was an example of “neo-Darwinist thought”.
I review of your own posts might be informative. Do you dispute that beneficial mutations occur?
No, of course not. However, I would point out (AGAIN!) that a "beneficial" means "in relation to the current environment. Therefore, the same allele may be beneficial in one generation and deleterious in the next. It isn't a property of an allele, but of an allele-within-the-current-environment. Hence the concept of "adaptation".
Do you dispute that those mutations which increase in frequency in future generations of the population are by definition beneficial. (Except when they aren’t.)
Yes, I do dispute that. You said "generations" plural. Beneficial only refers to the change in frequency between two generations. So your parenthesis is irrelevant. Some alleles may oscillate between beneficial and deleterious by the generation (read The Beak of the Finch if you haven't already). You are seeing inconsistencies in my posts not because they are inconsistent but because you consistently misread them :)
Do you dispute that according to population genetics models these mutations will increase in the population to the point where they become fixed?
No, but that is because many population genetics models make gross simplifying assumptions (like setting a selection coefficient as a fixed property of an allele, rather than as a variable that may itself be modulated by allele frequency. Certainly some alleles do become fixed. But many (most?) genes have polymorphisms. What is far more important is the other end - that some alleles drop right out of the gene pool.
Do you dispute that this is the process by which one species is changed into another species?
Yes. One species is never "changed into another species". You are confusing speciation with adaptation. Populations speciate when they diverge (and, usually, adapt as well). Populations adapt when their allele frequencies adjust to optimise survival in a changing environment. You can have adaptation over time without speciation; you can have speciation where one lineage undergoes conservative evolution (i.e. remains very similar to the ancestral population) while the other adapts to become very different. But that doesn't mean that "one species changed into another". It means, simply, that the population split and adapted independently.
Do you dispute that all the above is neo-darwinian theory?
Most of it. But, as my then-eight-year-old once said about his teacher who knew less about zoology than he did, "fortunately I was able to put her right". Now, I'm happy to defend any of the above against challenges to its likelihood, but I hope that at least we have put to rest the straw man of evolution that I'm supposed to have espoused :)
Give us break Elizabeth, really.
Glad to have been able to help :)Elizabeth Liddle_{June 30, 2011
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And DrREC, in your 'unbiased' neo-Darwinian world-view, exactly how are we to take these results??? Mutations : when benefits level off - June 2011 Excerpt: After having identified the first five beneficial mutations combined successively and spontaneously in the bacterial population, the scientists generated, from the ancestral bacterial strain, 32 mutant strains exhibiting all of the possible combinations of each of these five mutations. They then noted that the benefit linked to the simultaneous presence of five mutations was less than the sum of the individual benefits conferred by each mutation individually. http://www2.cnrs.fr/en/1867.htm?theme1=7 ,,,so DrREC, in your 'unbiased' neo-Darwinian world-view, these 5 mutations, which were gathered after 50,000 generations (equivalent to 1,000,000 years of proposed human evolution) when combined, producing 'less' of a benefit, is not a problem at all??? Does the fact that they were not truly 'beneficial' in terms of building functional molecular complexity matter to you at all??? Michael Behe's Quarterly Review of Biology Paper Critiques Richard Lenski's E. Coli Evolution Experiments - December 2010 Excerpt: After reviewing the results of Lenski's research, Behe concludes that the observed adaptive mutations all entail either loss or modification--but not gain--of Functional Coding ElemenTs (FCTs) http://www.evolutionnews.org/2010/12/michael_behes_quarterly_review041221.html Lenski's e-coli - Analysis of Genetic Entropy Excerpt: Mutants of E. coli obtained after 20,000 generations at 37°C were less “fit” than the wild-type strain when cultivated at either 20°C or 42°C. Other E. coli mutants obtained after 20,000 generations in medium where glucose was their sole catabolite tended to lose the ability to catabolize other carbohydrates. Such a reduction can be beneficially selected only as long as the organism remains in that constant environment. Ultimately, the genetic effect of these mutations is a loss of a function useful for one type of environment as a trade-off for adaptation to a different environment. http://www.answersingenesis.org/articles/aid/v4/n1/beneficial-mutations-in-bacteria Moreover DrREC, for those of us not predisposed to look at the world through Darwinian glasses, this negative return on 'benefit' is to be expected because of the poly-constraint to evolvability brought on by the poly-functionality of the classical information encoded onto DNA; Poly-Functional Complexity equals Poly-Constrained Complexity http://docs.google.com/Doc?docid=0AYmaSrBPNEmGZGM4ejY3d3pfMjdoZmd2emZncQ DNA - Evolution Vs. Polyfuctionality - video http://www.metacafe.com/watch/4614519bornagain77_{June 30, 2011
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arg, i just read that over. It makes it look like Elizabeth was answering yes to a question I was asking. That is not the case. Sorry about that.Mung_{June 30, 2011
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Yet another note on the incoherence of modern evolutionary theory ME: Do you dispute that those mutations which increase in frequency in future generations of the population are by definition beneficial. (Except when they aren’t.) Elizabeth: Yes, eventually some mutations do become fixed (as, interestingly, do some neutral mutations as well as slightly deleterious ones, but beneficial ones are more likely to go to fixation). Now since it is clear that both neutral and deleterious mutations can become fixed, one cannot simply look at the frequency of a mutation and whether it is increasing to determine that a mutation is beneficial. One cannot simply assume from the presence of a fixed mutation that it was fixed because it was beneficial. So what then is a beneficial mutation? How do we tell?Mung_{June 30, 2011
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Elizabeth Liddle:
I would like to know where PaV got the idea that the above was an example of “neo-Darwinist thought”.
I review of your own posts might be informative. Do you dispute that beneficial mutations occur? Do you dispute that those mutations which increase in frequency in future generations of the population are by definition beneficial. (Except when they aren't.) Do you dispute that according to population genetics models these mutations will increase in the population to the point where they become fixed? Do you dispute that this is the process by which one species is changed into another species? Do you dispute that all the above is neo-darwinian theory? Give us break Elizabeth, really.Mung_{June 30, 2011
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"As BA77 has shown, we just recently have seen that epistasis is limited in its effects." Wait, is that in reference to the paper "Negative Epistasis Between Beneficial Mutations in an Evolving Bacterial Population," which Tim Cooper himself posted here to correct the misunderstanding of? https://uncommondescent.com/intelligent-design/recent-papers-confirm-that-genetic-entropy-decreases-fitness/#comment-384735 You might want to read the paper, and dialogue with the authors. I say this because I have read the paper, and find this post somewhat puzzling. There are some unjustified leaps in logic. Bjørn Østman blogs here: http://pleion.blogspot.com/2011/06/using-deleterious-mutation-to-cross.htmlDrREC_{June 30, 2011
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PaV:
The reality is that Darwinists don’t have a way of explaining how speciation takes place in any kind of mathematically rigourous fashion. I have found no explanation for how new species arise given neo-Darwinian thinking. Perhaps you can point me in that direction. Give me some sort of resource. Now, there are lots of attempts at explaining how new species arise; but they all end up floundering. So, surprise me!
OK, fair enough! But first let's deal with a couple of straw men: The idea that beneficial mutations sweep through populations in sequential waves until they become "fixed" is simply not a hypothesis I've ever met, and is certainly not supported by any evidence. Yes, eventually some mutations do become fixed (as, interestingly, do some neutral mutations as well as slightly deleterious ones, but beneficial ones are more likely to go to fixation). A better mental picture of the neo-Darwinist (if I must use that term! Not sure I like it because I'm not anti-Margulis for instance) is of lots of nearly-neutral mutations occurring all the time i.e. new alleles appearing all the time, some of which result in a slightly fitter genotype, some a slightly less fit genotype, but, as I tried to convey in my response to Joseph above, the concept of fitness is always in relation to a single generation, and what is slightly beneficial in one generation may be slightly deleterious in another. Not only that, but as the article in your OP illustrates (nice article by the way!) the fitness conferred by a single mutation doesn't just depend on the current external environment, it also depends on the genes it shares an organism with. And while the article referenced in the OP concerns asexually reproducing species (which are a rather special case) things get rather more complicated in sexually reproducing species, because they have the great advantage of being able to "mix and match" genes within genotypes. So what we have, in a given population, is a great many genotypes (i.e. lots of alleles, none of which are, by definition, "fixed") all being swapped around with each new generation, and the ones that tend to promote successful progeny become more common and the ones that don't become less common, although which ones do what will tend to change even from generation to generation, and certainly as the external environment changes. So the kind of "sweep" that occurs is not that a single mutation "sweeps" through the population, but that there are lots of different alleles, and that the frequency distribution of each allele changes from generation to generation, the ones that tended to be associated with more progeny increasing in frequency, and the ones that tended to be associated with fewer, reducing. And so the mean fitness of the population tends to optimise with the alleles that contribute to the most successful gene cocktails (aka genotypes) in that environment, at that time, becoming the most frequently. Over time, the least successful alleles may drop out of the gene pool altogether, and, if they are ever needed again, will have to mutate ab initio (which occasionally happens). But that isn’t “speciation” – that’s simply adaptation. Speciation happens when a population diverges for some reason, into two populations that don’t, or rarely interbreed, for example if they become separated by a mountain range, or a stretch of water. When that happens, adaptation continues, but the environmental history of the two populations will change – one side of the mountain may be drier than the other, or there may be different predators. And, because the two populations are now adapting independently to environmental changes, they will not only tend to differ from their ancestral populations, but also from each other, to the point where they could not interbreed even if the barrier between them was removed. And it is this divergent adaptation that we call “speciation”. Adaptation is what happens down a single lineage; speciation is the process by which one population lineage diverges into two. Again, I’m not trying to convince you that this happens – merely explain what it is that “evolutionists” actually envisage happening :)Elizabeth Liddle_{June 30, 2011
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Sorry Elizabeth, you'll just shrug it off anyway as you always do, so I think I'll go have a bite instead!bornagain77_{June 30, 2011
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EL:
Do you have any source for the position you described? I’d dearly like to know where you got it!
The reality is that Darwinists don't have a way of explaining how speciation takes place in any kind of mathematically rigourous fashion. I have found no explanation for how new species arise given neo-Darwinian thinking. Perhaps you can point me in that direction. Give me some sort of resource. Now, there are lots of attempts at explaining how new species arise; but they all end up floundering. So, surprise me!PaV_{June 30, 2011
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OK, I found it - Dr Sternberg is not saying that
single mutations sweep through populations, and, as these mutations become ‘fixed’, increases in ‘fitness’ until such time that a ‘new species’ arises
. From the sound of it, he isn't even a neo-Darwinist. I would like to know where PaV got the idea that the above was an example of "neo-Darwinist thought". I have never heard anyone propose that, let alone a neo-Darwinist. Dr Sternberg certainly isn't proposing it. So who is?Elizabeth Liddle_{June 30, 2011
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Sorry, ba77, that video won't play for me. Can you link me to Dr Sternberg's written papers?Elizabeth Liddle_{June 30, 2011
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Why Elizabeth, Dr. Sternberg speaks of such right here: Whale Evolution Vs. Population Genetics - Richard Sternberg PhD. in Evolutionary Biology - video http://www.metacafe.com/watch/4165203/bornagain77_{June 30, 2011
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F/N: Co-ordinated mutations to gain a benefit? Isn't that just a tad suspicious?kairosfocus_{June 30, 2011
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BA 77:
“a very rough but conservative result is that if all the sequences that define a particular (protein) structure or fold-set where gathered into an area 1 square meter in area, the next island would be tens of millions of light years away.” Kirk Durston
That's a couple of galaxies over. GEM of TKIkairosfocus_{June 30, 2011
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But PaV, I'm not sure where you're getting that "simplistic neo-Darwinian" thought from! It's nothing like any evolutionary theory I've ever heard of! Do you really think that "Darwinian" (or "neo-Darwinian") theory posits that:
single mutations sweep through populations, and, as these mutations become ‘fixed’, increases in ‘fitness’ until such time that a ‘new species’ arises.
? Because if so, I'm not surprised that you think it's bunk! It is! Do you have any source for the position you described? I'd dearly like to know where you got it!Elizabeth Liddle_{June 30, 2011
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I want to know how, having gone into another dimension, they get back into this one.Mung_{June 30, 2011
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EL:
Now, imagine (which is hard) many many dimensions. Yes there will be valleys, but there are many ways of getting across them by traversing different dimensions.
However, "crossing" any of these "dimensions" cannot be brought about by any single, non-interacting mutation. This runs counter to simplistic neo-Darwinian thought wherein single mutations sweep through populations, and, as these mutations become 'fixed', increases in 'fitness' until such time that a 'new species' arises. This doesn't help the Darwinian model.PaV_{June 30, 2011
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