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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
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Author | Topic: Evolution Requires Reduction in Genetic Diversity | |||||||||||||||||||||||||||||||||||||||||||||||
Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
trochiloides is the ancestral species. Now imagine there are 10 mutations between trochiloides and ludlowi - not enough to cause infertility. There is also 10 mutations between trochiloides and obscuratus so they are able to hybridize freely as well. Also 10 mutations between ludlowi and viridanus and between obscuratus and plumbeitarsus, all able to freely hybridize. However, between viridanus and plumbeitarsus there are 40 total accumulated mutations. So, now the species on the extremes of the ring have significant differences and no longer can interbreed.
COULD happen that way, OK, I'll give you that. But you're making a hypothetical case you can't prove. We do need to have some kind of experiment to prove this one way or the other, and it would have to involve DNA reading. I wish I could lay out how the mere processes of repeated migration, isolation and inbreeding lead to "speciation" but I'm not able to juggle the genetic possibilities well enough. But how about the cheetah for an example. I know you'll object that it was the result of a bottleneck, but their main genetic characteristic is their many fixed loci, which is also what I expect to see at the end of a series of migrations, isolations and inbreedings. I haven't heard anything about mutations being the cause of their inability to interbreed with other cats, but simply the effect of the bottleneck on their genome, which changed it sufficiently for it to be a mismatch with other cats. I'm sure there must be plenty of examples of what I have in mind out there but I'm not very good at finding stuff. Edited by Faith, : No reason given.
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NoNukes Inactive Member
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It would be an extremely rare population split that did not. It would be an extremely rare population split that did not. You aren't thinking. Population splits bring about changed gene frequencies Even assuming that this is correct, you are describing a change that occurs after the populations split. Accordingly the change is not the cause of such splits. So what is the cause? How about all of the stuff discussed in that article that you claim is wrong? How about the list of examples I gave in my last post? Further, lots of things cause frequencies to drift even without a split. How about changes in the environment or genetic drift. Clearly you are not describing a cause and effect relationship. At least it is clear that you are not providing the sole cause for changes in frequency. And you still are not addressing the point. Your claim is that a remix of gene frequencies can cause populations to become incapable of inter breeding. I have pointed out that you cannot produce any mechanism for such, and your response was that mutations produced the same thing as a reshuffling. Presumably you ducked answering the question directly because you did not have a mechanism. After I gave you reasons why mutations don't simply provide a new allele for a gene, and thus differ from simply remixing you haven't made a single effort to respond to the hole in your argument that I pointed out. Nothing you say here does any such thing except change the subject, refuse to respond, and then claim that I am the problem. I suspect that the problem is that you have no argument. You seem to want to talk about everything else except the petard you are hoisted upon. Well just stay up there, with your feet dangling. Edited by NoNukes, : No reason given.Je Suis Charlie Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846) If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams
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NoNukes Inactive Member |
I'll argue it if you like but it ought to be obvious that migration is a form of RANDOM selection, not purposeful selection like natural selection, because it randomly creates a new set of alleles that comes to form a new subpopulation Explain how this is not hogwash. Where do the new set of alleles come from if there is no mutation? Total nonsense.Je Suis Charlie Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846) If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams
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herebedragons Member (Idle past 887 days) Posts: 1517 From: Michigan Joined:
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I'll argue it if you like but it ought to be obvious that migration is a form of RANDOM selection I suppose if you want to create your own definitions. Migration is the movement of individuals between populations. Migration is gene flow, it does not select anything, it moves genes between populations. It is not just movement of genes out of a population to form subpopulations but it also involves migration INTO populations.
Genetic drift is also random selection and isolation of a subset of alleles, not purposeful. Genetic drift is more like "random selection" as you call it. It works by eliminating individuals in a population regardless of their genotypes or fitness.
"Fitness" is one of those tenets of the ToE that really doesn't mean anything: it's rarely the cause of a genetic change. It most certainly does mean something, but no, fitness doesn't cause genetic change, selection acting on fitness causes genetic change. It can and has been demonstrated in the lab and in field experiments.
but I'm arguing that most microevolutionary changes are the result of random reshufflings of alleles as in migration. But where is the evidence of this? These definitions have come about because of work done by biologists studying these processes. You are making up new definitions to accommodate your view; you can't define yourself into being right.
I also object to that breakdown of the supposed different routes to Speciation on the Wikipedia page of that title. All those routes are basically the same route with the same genetic and phenothypic outcome, the distinctions are artificial and ultimately meaningless. Modes of speciation are fairly controversial in evolutionary biology. The major distinction is the amount of gene flow present between the main population and the subpopulation. Allopatric speciation has no gene flow because of a physical barrier. Peripatric has isolation of a subpopulation but no physical barrier so there is still potential for gene flow. In Parapatric the subpopulation is not isolated and there can still be gene flow between the main population and subpopulation. For Sympatric the subpopulation forms within the main population so there is potential for significant gene flow. So potential for gene flow is the key distinction between the modes of speciation. ABE: The question for the these different modes of speciation then becomes - how do you prevent or minimize migration (ie. gene flow) between the main population and the newly formed subpopulation? Allopatric makes sense - the physical barrier prevents migration, but for the others the answer is not so clear cut. HBD Edited by herebedragons, : No reason given.Whoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca "Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem. Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.
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herebedragons Member (Idle past 887 days) Posts: 1517 From: Michigan Joined:
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COULD happen that way, OK, I'll give you that. But you're making a hypothetical case you can't prove. Hypothetical, yes - for simplicity sake. Can't prove? well...
Speciation by distance in a ring species Abstract: quote: Look this paper over and give me your critique. Of particular interest is Fig 2. Keep in mind this paper is a bit older and they seem to lean toward the sympatric or parapatric modes of speciation. More recent work has suggested that there probably was isolating barriers between populations at one time in their evolutionary history. HBDWhoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca "Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem. Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.
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NoNukes Inactive Member
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MY point was you don't know if the mutations have occurred or have anything to do with the effect. I rather suspect the low frequency of such mutations precludes them having much effect anyway. But sure they COULD have if they DO occur The above statement makes no sense. Calling something rare is an acknowledgement that it does occur. And of course none of that explains how reshuffling of alleles that already existed in a population creates a mating incompatibility. You've acknowledged that mutations could have the effect, but that does nothing to answer the question. Edited by NoNukes, : No reason given.Je Suis Charlie Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846) If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams
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NoNukes Inactive Member |
It most certainly does mean something, but no, fitness doesn't cause genetic change, selection acting on fitness causes genetic change. It can and has been demonstrated in the lab and in field experiments. Statements like this can seem Lamarkian to people who are looking for that in the theory of evolution. Fitness just measures the ability of a phenotype and its supporting genetic variety to survive. Disappearing genotypes change the genetic make up of the population because of their absence. But fitness is not a means for introducing genetic variety. Why in the world the role of fitness would be a point of attack for the theory of evolution is quite bizarre. Unlike some of the other issues, the process of natural selection is easily observed. I suppose any port in a storm... Edited by NoNukes, : No reason given.Je Suis Charlie Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846) If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams
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Denisova Member (Idle past 3246 days) Posts: 96 From: The Earth Clod.... Joined:
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Well, here are they AGAIN.
It is quite annoying I must say. Here are the major assumptions of your position:
No. 1 cannot be empirically backup up by you. That is, until now I’ve seen nothing yet. There are several ancient genomes sequenced as I pointed out to you: Denisova, Neanderthal, Heidelbergensis, ancient Homo Sapiens. These genomes are also mutually compared by geneticists. All those genomes are genetically very close. As a matter of fact, Svante Pbo and his teams (and others as well) found that at least Denisova, Neanderthal and Sapiens have interbred. But, anyhow, we HAVE the genomes sequenced of very old hominids. And these show you ARE WRONG. Because when Denisova, Neanderthal, ancient Sapiens genomes turn out to be very similar to extant human ones, the apparently weren't many genes silenced and turned into junk DNA. Moreover, John Sanford tried to prove empirically for a decline in genetic diversity in genomes. He utterly failed. Even cheating on the work of others couldn’t help him. Now, I already provided this stuff 4 or 5 times, if not more. May I FINALLY have you elaborations on this? No. 2 is directly refuted by the Lenski experiment, along with an abundance of similar experiments on both bacteria and sexually reproducing eukaryotes like beetles, fruit flies and yeast. I even spelled out the results of Lenski’s experiment in post Message 431. Percy had to remind you to provide an answer too. As these experiments refute your assumption, may I have your elaboration on these? Now I already asked this 4 or 5 times. When do we get the answers? But there are more questions unanswered by you:
And of course this very old point, form the very beginning when I joined the debate here:
Now, in post Message 461 I already remarked:
Denisova writes: And my arguments on it HAVE NOT BEEN ADDRESSED until now.And I am awaiting for 8,9 posts by now. You may also go back to my post Message 462. Or Message 474. Or Message 479. In the latter I wrote:
denisova writes: Let's see what I have provided until now:E. coli experiment demonstrating genetic innovation by mutations in conjunction with selection is occurring and adding to phenotype diversity other experiments on prokaryotes showing the same Dachshunds and the like have short legs due to genetic mutations, empirical studies showed the fossil record (without even having dated it) shows a constant emergence of new life forms with completely new and different genomes and phenotypes several empirical studies on eukaryotes (fruit flies, yeast, beetles), demonstrating genetic innovation by mutations in conjunction with selection is occurring in sexually reproducing animals as well. "No evidence provided" you did say? RIGHT. Or maybe you try post Message 522. Or Message 555? You are also found to be profoundly wrong on the effects of population bottlenecks.
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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
dup
Edited by Faith, : No reason given.
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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
Explain how this is not hogwash. Where do the new set of alleles come from if there is no mutation? Total nonsense. Have you completely missed the point? The new set of alleles refers to the same alleles in new proportions or frequencies. If you aren't getting that much there's no communication here at all. Edited by Faith, : No reason given.
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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
I'll argue it if you like but it ought to be obvious that migration is a form of RANDOM selection
I suppose if you want to create your own definitions. No change in definitions at all, change in assessment or analysis.
Migration is the movement of individuals between populations. Migration is gene flow, it does not select anything, it moves genes between populations. It is not just movement of genes out of a population to form subpopulations but it also involves migration INTO populations. That's ridiculous, they are two engtirely different things with entirely different results. One is additive, gene flow, the other is selective or subtractive. But if both are described by the same term that's just another case of evolutionist confusion. So shall I call what I'm talking about EMIGRATION perhaps and the other IMMIGRATION? That would make more sense.
Genetic drift is also random selection and isolation of a subset of alleles, not purposeful.
Genetic drift is more like "random selection" as you call it. It works by eliminating individuals in a population regardless of their genotypes or fitness. It eliminates alleles the way all the processes I'm calling selective do, and so does migration/emigration as I've been saying all along. Yes, random selection in both cases.
"Fitness" is one of those tenets of the ToE that really doesn't mean anything: it's rarely the cause of a genetic change.
It most certainly does mean something, but no, fitness doesn't cause genetic change, selection acting on fitness causes genetic change. It can and has been demonstrated in the lab and in field experiments. Oh it isn't that there aren't adaptations but my argument is that this is far from the major cause of change claimed by the ToE. Peppered moths and pocket mice are the only examples I can think of and they don't form permanent new subpopulations, they alternate according to the environment. As I've been arguing, which you may not have noticed, such famous examples of adaptation as Darwin's finches more likely formed through mere migration, or random selection of alleles, than in response to the environment.
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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
but I'm arguing that most microevolutionary changes are the result of random reshufflings of alleles as in migration.
But where is the evidence of this? These definitions have come about because of work done by biologists studying these processes. You are making up new definitions to accommodate your view; you can't define yourself into being right. No, I'm thinking through the realities that the ToE relegates to assumptions. The ToE says natural selection so everybody assumes natural selection whether it's involved or not. And speaking of evidence let me know when you have some for your hypothetical mutations.
I also object to that breakdown of the supposed different routes to Speciation on the Wikipedia page of that title. All those routes are basically the same route with the same genetic and phenothypic outcome, the distinctions are artificial and ultimately meaningless.
Modes of speciation are fairly controversial in evolutionary biology. The major distinction is the amount of gene flow present between the main population and the subpopulation. Allopatric speciation has no gene flow because of a physical barrier. Peripatric has isolation of a subpopulation but no physical barrier so there is still potential for gene flow. In Parapatric the subpopulation is not isolated and there can still be gene flow between the main population and subpopulation. For Sympatric the subpopulation forms within the main population so there is potential for significant gene flow. So potential for gene flow is the key distinction between the modes of speciation. Potential for gene flow is meaningless; either there is gene flow or there is not.
ABE: The question for the these different modes of speciation then becomes - how do you prevent or minimize migration (ie. gene flow) between the main population and the newly formed subpopulation? Why would you try to minimize it? It's a reality, just take note of it and make your focus the ones without gene flow if you want the least complicated view of speciation. But I do not use the word migration the way you are using it, it's confusing. But if I have to now I'll say emigration. As I use it it's a form of selection.
Allopatric makes sense - the physical barrier prevents migration, but for the others the answer is not so clear cut. it's unimportant. Gene flow may occur or not for many reasons. Edited by Faith, : No reason given. Edited by Faith, : No reason given. Edited by Faith, : No reason given.
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Denisova Member (Idle past 3246 days) Posts: 96 From: The Earth Clod.... Joined:
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MY point was you don't know if the mutations have occurred or have anything to do with the effect. I rather suspect the low frequency of such mutations precludes them having much effect anyway. But sure they COULD have if they DO occur. Of course they DO OCCUR.As demonstrated by me and others here abundantly:
Well, shortly, the dozens of questions and points dodged by you. I am afraid I also have to explain evolution theory to you - again. The low frequency of beneficial mutations is quite irrelevant.The reason for this is natural selection. Beneficial mutations are favoured. The reason for this is BECAUSE they are beneficial. And "beneficial" or "deleterious" are defined in terms of fitness: survival and/or reproduction chances. Deleterious mutations are weeded out. That's why in most species only a rather tiny part of the newborn eventually will make it and reproduce themselves, passing their genes on to the next generation. In frogs the vast majority of the fertilized eggs will survive. In mice likewise. Even in humans fertility research found that only 15% of all conceptions end up in the birth of a living child. Then the selective pressure persists. In all species a considerable percentage of newborns will not manage to survive up to reproduction age. And when that hurdle is taken, sexual selection starts, leaving especially many male animals abiding their lives without ever passing their genes to the next generation. Many studies even revealed that there is a direct correlation between the selective pressures animal species are experiencing within their habitat and the number of offspring: the more fierce the pressure, the more offspring. Beneficial ones though are favoured. they will not be weeded out by natural selection. Let's do some calculations:
You see, in statistics we have the law of great numbers. It tells that, how small the odds for a particular event may be, if the number of trial is large enough, that event MOST LIKELY will occur.
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Denisova Member (Idle past 3246 days) Posts: 96 From: The Earth Clod.... Joined: |
Oh it isn't that there aren't adaptations but my argument is that this is far from the major cause of change claimed by the ToE. Peppered moths and pocket mice are the only examples I can think of and they don't form permanent new subpopulations, they alternate according to the environment. As I've been arguing, which you may not have noticed, such famous examples of adaptation as Darwin's finches more likely formed through mere migration, or random selection of alleles, than in response to the environment. You better start to read Darwin before starting this - I am sorry to put it this way but your attitude is getting terrible annoying here - TATTLING and misrepresenting of the things he wrote. Here you go: http://darwin-online.org.uk/content/frameset?viewtype=tex.... Darwin described very PAINSTAKINGLY and in TERRIBLE detail how the phenotype of the finches responded to the different ENVIRONMENTAL conditions. BECAUSE when populations of animals migrate, they move into ANOTHER ENVIRONMENT with different conditions and selective pressure to cope with. Hence, finches that flew from one island to another were found to adapt to the conditions over there. Other food sources but lacking the ones in their former homeland. And adapting they did. Darwin painstakingly noted how the different forms of beaks perfectly match the different food sources the distinct finch species thrived on. This kind of field observations and even experiments on the effects of natural selection count into the the hundreds of thousands - and I think I do not exaggerate.
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herebedragons Member (Idle past 887 days) Posts: 1517 From: Michigan Joined: |
Statements like this can seem Lamarkian to people who are looking for that in the theory of evolution. I'm not sure how it seems Lamarkian... sort of anthropomorphic maybe, seeming as though these forces are acting purposefully.
Fitness just measures the ability of a phenotype and its supporting genetic variety to survive. Disappearing genotypes change the genetic make up of the population because of their absence. But fitness is not a means for introducing genetic variety. Right, fitness doesn't change genetic make up but selection does - acting upon the relative fitness of individuals. An important point to this discussion is how the various forces affect genetic diversity. Here is a table that helps explain it:
(Adapted from: Conner and Hartl (2004). A primer of ecological genetics. Sinauer Associates) * Selection would most often tend to decrease variation except in cases such as heterozygote advantage were both homozygotes are being selected against in which case would tend to increase variation.
Why in the world the role of fitness would be a point of attack for the theory of evolution is quite bizarre. I think the main point of contention, at least with creationists, is the idea of "survival of the fittest" which seems malevolent to them - especially when applied to humans. I don't particularly like the phrase myself as it misses the nuances of how selection and fitness actually work. HBDWhoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca "Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem. Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.
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