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Author | Topic: Explaining the pro-Evolution position | |||||||||||||||||||||||
jar Member (Idle past 415 days) Posts: 34026 From: Texas!! Joined: |
AZPaul3 writes: Any pigeon will give you that. As well as scales and feathers too.
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Dr Adequate Member (Idle past 306 days) Posts: 16113 Joined: |
Ok, any mutation that is detrimental causes the loss or reduced fitness of that member. Right, why do you mention it?
Ok, but you must also assume the mice have adequate food, adequate water, no disease, no thermal stress... No, just that before the introduction of the predators they maintained their population at the level that it was in fact at in the face of these pressures.
I don't agree with your terminology or concept. Increasing food sources reduces selection pressures on populations ... Not if (as I explicitly said) "each [...] requires a different adaptation to exploit effectively". Then they impose selection pressures.
There is no such thing as pressures of opportunity. Wrong. See my example.
The phenotypes of populations can be altered markedly by recombination. Consider the variants seen in the canine family in just a few thousand years of selective breeding. However, the creation of new alleles by rmns is an extremely slow process, even under ideal circumstances with the correct selection pressures. And if you have multiple directional selection pressures acting simultaneously, the process only slows further. Wrong (in general). See my math.
Take a closer look at the Lenski starvtion selection pressure experiment, he maintains his populations at e7-e8. Yet is still takes over a thousand generations per beneficial mutation. Do you think that rmns will work more quickly if he subjects his populations to thermal stress as well as starvation stress concurrently? Yes if this involves soft selection, no if the selection is too hard, i.e. if the additional stress reduces the population to such a level that this outweighs the effect of concurrent evolution. Edited by Dr Adequate, : No reason given.
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Kleinman Member (Idle past 356 days) Posts: 2142 From: United States Joined: |
quote:I had a link to a paper which is now dead given to me by Edward Max. In that link, they studied the genomes of reptiles and the genomes of birds and looked at which genes would have to be transformed to transform scales to feathers. They identified at least 8 genes which would have to be transformed. They didn't say how many mutations in each gene. quote:Last I checked, nobody has sequenced the dinosaur genome except in Jurrasic Park. quote:The equations I derived are general equations applicable to any example of rmns. They are applicable to all real, measurable and repeatable examples of rmns. If you use combination selection pressures on birds, they will not be able to evolve by rmns any differently than any other replicator. quote:Certainly, but if you are going to take a life form that can not fly and try to give that life form the alleles necessary to fly by rmns, those life forms are already the honored guests at dinner. quote:Thanks, you are correct. My point is, most real, measurable and repeatable examples of rmns are cases where there are targeted selection pressures. For example, antimicrobial resistance, herbicide resistance and so on. Have you ever seen a case where a microbe evolves resistance to iodine? It doesn't happen because iodine reacts with too many biological molecules, too many genetic loci targeted. Starvation and thermal stress target too many genetic loci simultaneously for replicators to evolve efficiently to these kinds of selection pressures. The Lenski experiments are examples of this. And when these pressures are combined, the ability to evolve to these pressures becomes multiplicatively more difficult to evolve to by rmns. quote:Fair enough, it's the directional selection pressures which I am talking about which drive rmns. quote:Again, fair enough, but I think you now recognize that single drug treatment is useless, two drug therapy works better, three drug therapy handles the vast majority of cases, four drug therapy... My paper on the evolution of drug resistance to multiple simultaneous selection pressures addresses this. There's a pattern which emerges as you add selection pressures. You are forcing lineages to do several orders of magnitude more replications for each additional selection pressure for each beneficial mutation required for adaptation. This is easy for the lineages to accomplish the amplification required when the selection pressures are applied sequentially. However, when done simultaneously, the amplification process is suppressed by the various selection pressures. quote:Fixation is a common notion taught in evolutionary biology but it is based on an incorrect understanding of the physics. Fixation is based on the notion that natural selection is a conservative phenomenon. Haldane in his substitution model is based on the assumption that the increase in one variant must be accompanied by a decrease in another variant (hence substitution). Kimura in his diffusion fixation model uses the same basic concept. In order for a variant to be fixed, the other variants must disappear. But that is not what happens with rmns. First, the probabilities of a beneficial mutation occurring are not dependent on the relative frequency of the variant but the actual number of members replicating who would benefit from the particular mutation. Second, rmns can occur with multiple different variants, each taking their own particular evolutionary trajectory to improved fitness and it doesn't matter what the other lineages are doing as long as they are not competing for the resources of the environment. None of the variants need to be fixed in order for this process to happen. Here's a video demonstrating this: Scientists create video of bacteria evolving drug resistance. I've sent an email to the people doing this experiment to try the experiment with 2 and then 3 drugs instead of the single drug experiment. Fixation is not the key variable for evolution by rmns, it is amplification to improve the probability of the next beneficial mutation.
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Kleinman Member (Idle past 356 days) Posts: 2142 From: United States Joined: |
quote:Doesn't matter, if the alleles don't exist in the lineage, they have to come from someplace. Modern reptiles don't have the alleles to produce feathers, where did "ancient" reptiles get the alleles?
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Dr Adequate Member (Idle past 306 days) Posts: 16113 Joined: |
Last I checked, nobody has sequenced the dinosaur genome except in Jurrasic Park. I didn't say doing the calculation would would be easy or indeed possible. I merely say that you have not in fact done it.
The equations I derived are general equations applicable to any example of rmns. And what do they say? Because if all they say is that simultaneous beneficial mutations are unlikely, then this is true but does not do what you want it to, i.e. cast doubt on bird evolution.
Certainly, but if you are going to take a life form that can not fly and try to give that life form the alleles necessary to fly by rmns, those life forms are already the honored guests at dinner. Well, you know, non-flying dinosaurs also managed to survive for about 160 million years.
Starvation and thermal stress target too many genetic loci simultaneously for replicators to evolve efficiently to these kinds of selection pressures. The Lenski experiments are examples of this. Except that the bacteria in that experiment did evolve effectively; they are demonstrably fitter than their ancestors. According to WP: "By 20,000 generations the populations grew approximately 70% faster than the ancestral strain."
Again, fair enough, but I think you now recognize that single drug treatment is useless, two drug therapy works better, three drug therapy handles the vast majority of cases, four drug therapy... My paper on the evolution of drug resistance to multiple simultaneous selection pressures addresses this. There's a pattern which emerges as you add selection pressures. I know, I did the math. And the pattern is different depending on how hard the selection pressures are.
Fixation is based on the notion that natural selection is a conservative phenomenon. No.
Second, rmns can occur with multiple different variants, each taking their own particular evolutionary trajectory to improved fitness and it doesn't matter what the other lineages are doing as long as they are not competing for the resources of the environment. But eventually they certainly will be. --- Again, I would point out that the traits that make birds birds and not dinosaurs are fixed in birds, so it would be perfectly reasonable to measure the speed of dinosaur-to-bird evolution in terms of the rate at which the genes were fixed.
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Kleinman Member (Idle past 356 days) Posts: 2142 From: United States Joined: |
quote:No Doc, what I am saying is that rmns works the same for all replicators. rmns works in a cycle of beneficial mutation followed by amplification of that mutation to improve the probability of another beneficial mutation occurring on that lineage. quote:I have done the math and I understand that it's behind a paywall but it's there. Here's the first step in doing the math, it is determining the possible outcomes for a mutation. P(−∞ < X < +∞) = P(Ad) + P(Cy) + P(Gu) + P(Th) + P(iAd) + P(iCy) + P(iGu) + P(iTh) + P(del)+ = 1 Where the i term denotes insertion, del denotes deletion, ... denotes any other possible mutation you can think of.
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Kleinman Member (Idle past 356 days) Posts: 2142 From: United States Joined: |
quote:Why don't you bear us some empirical examples of your bad news?
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Coyote Member (Idle past 2127 days) Posts: 6117 Joined: |
You're fond of mathematical models, you do the homework and stop trolling us.
You said you got five minutes into that on-line lecture. Try the whole thing. It shows the stuff you're peddling us is invalid. Of course, I can see why you don't want to watch it...Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge. Belief gets in the way of learning--Robert A. Heinlein In the name of diversity, college student demands to be kept in ignorance of the culture that made diversity a value--StultisTheFool It's not what we don't know that hurts, it's what we know that ain't so--Will Rogers If I am entitled to something, someone else is obliged to pay--Jerry Pournelle If a religion's teachings are true, then it should have nothing to fear from science...--dwise1 "Multiculturalism" demands that the US be tolerant of everything except its own past, culture, traditions, and identity.
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Dr Adequate Member (Idle past 306 days) Posts: 16113 Joined: |
No Doc, what I am saying is that rmns works the same for all replicators. rmns works in a cycle of beneficial mutation followed by amplification of that mutation to improve the probability of another beneficial mutation occurring on that lineage. Amplification? You mean, as in this? And this, you say, improves the probability of another beneficial mutation? How? And why would it stop birds from evolving?
Here's the first step in doing the math ... Could we move forward to the steps that involve birds and dinosaurs?
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Kleinman Member (Idle past 356 days) Posts: 2142 From: United States Joined: |
The following is a response to post 182, 185
quote:Just trying to make sure I understand your scenario. quote:I guess so, ok so go on. quote:So some variant can us one food source, other variants use the second food source, and a third variant can us the remaining source? quote:You can reduce the selection pressures on a population which will allow for increasing diversity, so if you want to call that an opportunity, I guess so. quote:I've seen your math and you need to learn something about the concept of fixation, it has no bearing on rmns. quote:Is that like killing me softly with his song? You need to suggest to Lenski to run his experiment with both thermal stress and starvation stress so he doesn't have to wait a thousand generations per beneficial mutation. quote:The calculations for rmns are actually quite simple. quote:My calculations also say that if amplification doesn't occur, the probability of another beneficial mutation occurring on that lineage remains low. quote:Apparently they didn't have to escape from their predators by flying away. quote:Not bad for 20,000 generations and about 20 beneficial mutations. But considering that 30 generations of doubling should have given about e12 members with a given beneficial mutation, you have very slow amplification. Remember the uproar over Haldanes dilemma, 300 generations per evolutionary step? But Haldane's model is physically incorrect. quote:Do you think that the evolutionary trajectory is dependent on the intensity of selection? quote:You are wrong on this one Doc. Do a careful study of Haldane's and Kimura's work. It's based on the concept that an increase in one variant is linked with a decrease in the other variants. In fact Haldane's substitution model is analogus to a conservation of energy problem. Here's a link to a paper which describes this: Just a moment... Kimura's work is directly based on a diffusion equation which is also a conservative phenomenon. quote:They will be what? quote:You are wrong on this Doc. Fixation of an allele is neither necessary nor sufficient for rmns to occur. If you are so sure you are correct, explain why one variant must decrease in order for another variant to increase.
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Kleinman Member (Idle past 356 days) Posts: 2142 From: United States Joined: |
quote:What I mean by amplification is simply increase in number of members of a particular lineage. Replication is the principle random trial for rmns. There are two ways to increase the number of random trials, you can increase the number of members in a lineage and you can increase number generations that lineage is able to replicate. Here's an easy way to think of this. Let's say you want to know the probability of rolling at least a single 1 with the roll of 1 die 10 times or 10 dice once, or 5 dice rolled twice etc. They all give the same set of possible outcomes and probabilities. So if you have a large numbers of members in a given lineage, it doesn't take very many generations of replications to have a reasonable probability of getting that beneficial mutation. But once that beneficial mutation occurs on one of the members, it is the progenitor of a new subpopulation (lineage) which must now amplify in order to improve the probability of another beneficial mutation occuring to advance the rmns process. quote:It's the same math for all replicators.
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Dr Adequate Member (Idle past 306 days) Posts: 16113 Joined: |
So some variant can us one food source, other variants use the second food source, and a third variant can us the remaining source? I said different, not incompatible.
You can reduce the selection pressures on a population which will allow for increasing diversity, so if you want to call that an opportunity, I guess so. But the opportunities increase the selection pressures, because it is now adaptive to be able to take advantage of the opportunities.
I've seen your math and you need to learn something about the concept of fixation, it has no bearing on rmns. See my previous posts.
Is that like killing me softly with his song? No.
You need to suggest to Lenski to run his experiment with both thermal stress and starvation stress so he doesn't have to wait a thousand generations per beneficial mutation. Too late.
You are wrong on this one Doc. Do a careful study of Haldane's and Kimura's work. It's based on the concept that an increase in one variant is linked with a decrease in the other variants. That's not what conservative selection means. And I'm sure both Haldane and Kimura were aware that populations grow sometimes. And, knowing that, they did not find the concept of fixation invalid; and nor do I.
They will be what? They will be competing for the resources of the environment. A population cannot grow indefinitely.
You are wrong on this Doc. Fixation of an allele is neither necessary nor sufficient for rmns to occur. Again, this is a strange way of putting it. "Travelling to another country is neither necessary nor sufficient for air travel to occur". Sure. This does not prove that the concept of travelling to another country is meaningless or fictitious, or that one cannot do it by plane.
If you are so sure you are correct, explain why one variant must decrease in order for another variant to increase. This is not in fact necessarily the case; but it would be the case if the population size is steady, as is often the case in nature.
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Dr Adequate Member (Idle past 306 days) Posts: 16113 Joined: |
But once that beneficial mutation occurs on one of the members, it is the progenitor of a new subpopulation (lineage) which must now amplify in order to improve the probability of another beneficial mutation occuring ... How does this improve the probability of another beneficial mutation occurring? Do you mean just because the population will be larger as a result of the first beneficial mutation, or what?
It's the same math for all replicators. Well, the actual numbers would be different. C'mon, Kleinman. You say that dinosaur-to-bird evolution can't have taken place because it would take too long for birds to evolve from dinosaurs. In order to prove your point, it is necessary for you to calculate how long it would take birds to evolve from dinosaurs, and to show your working. If you can't do that, then while many other aspects of this thread may have been entertaining, you haven't even made a start on proving your point. Edited by Dr Adequate, : No reason given.
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PaulK Member Posts: 17825 Joined: Member Rating: 2.2 |
quote: This is hardly the sort of thing we can expect from someone who really had a scientific disproof of the theory of evolution. Universal common descent is not even a very important part of the theory - and it would be dropped if the evidence went against it, with very little effect on evolutionary theory. It is not even what I would expect from somebody who understands how to apply probability theory to long sequences of events.
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PaulK Member Posts: 17825 Joined: Member Rating: 2.2 |
quote: What a bizarre thing to say! Would you not agree that the alleles to create feathers are fixed in every bird population ? And obviously in at least many other dinosaur populations ? It is rather important to evolution that fixation does occur, and natural selection is one of the mechanisms by which it does occur. And I will add that frequency could be considered a conserved quantity for the simple reason that the sum of the frequencies (of alleles of a gene) must be 1. As you must surely know, through the connection to probability theory at least. Spouting nonsense does not help your case. Edited by PaulK, : No reason given.
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