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Author | Topic: Y.E.C. Model: Was there rapid evolution and speciation post flood? | |||||||||||||||||||||||||||||||||||||||
Faith  Suspended Member (Idle past 1465 days) Posts: 35298 From: Nevada, USA Joined: |
The interesting thing is, on most genes, as individuals, we shouldn't be varying from Adam and Eve's original 4, especially with the Noah bottleneck, because 300 generations of mutations shouldn't give a hit on an average sized gene per. person. So, if it's very easy to find a lot more than 4 alleles in a small sample of the population, our YEC model looks to be in trouble. Not if they are all neutral or deleterious mutations.
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bluegenes Member (Idle past 2498 days) Posts: 3119 From: U.K. Joined: |
Faith writes: bluegenes writes: There's a problem inherent with the model of building up the variation from a recent 4,500 yr old bottleneck. Not if you assume much greater genetic diversity among those on the Ark, especially much higher heterozygosity for more genes than we see today. I'm assuming the maximum heterozygosity for Adam and Eve, but the point is that for Noah + family, and even for us, the original 4 alleles would predominate at all loci. You cannot get the effect of easily finding lots at one locus. There wouldn't have been enough mutations to get the effect we see in the immune system.
Faith writes: More genes too. This is where I keep coming back to the idea that junk DNA is dead genes that used to be functional and contributed greatly to the greater genetic diversity, from which all the different species we see could easily have evolved since the Ark. We can look at stone age genomes, and they're just like ours, so that probably wouldn't be a good suggestion for our model (it would be too easily falsified).
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bluegenes Member (Idle past 2498 days) Posts: 3119 From: U.K. Joined: |
Faith writes: Not if they are all neutral or deleterious mutations. Over 300 generations, we would have a mutation of some kind on about 1 to 2% of our coding genes. The rest would be identical to those of Adam and Eve. So how come we can easily find hundreds of alleles on some of them without searching a great number of people?
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PaulK Member Posts: 17825 Joined: Member Rating: 2.2
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quote: I have to say that that is a bizarre answer. Neutral and deleterious mutations only spread by drift, and deleterious mutations have selection working against them. So they should not be any easier to find. Did you mean "not if they are all strongly beneficial mutations" ?
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Percy Member Posts: 22480 From: New Hampshire Joined: Member Rating: 4.8 |
Faith writes: Well, if I'm getting what you are saying, I think it's really only one that each person would contribute to the next generation. Each parent contributes only one allele to each baby, but many parents have more than one baby. For a given gene of Adam with alleles X and x, Adam could have contributed allele X to Cain and allele x to Abel.
(I got blue eyes from a combination of my parents' alleles: a b from my mother's Bb and a b from my father's bb; my sister got her brown eyes from our mother's B and of course our father's b) Eye color is determined by multiple genes, at least six, and there are more colors than just brown and blue
Again, we all get a gene made up of two alleles from our parents, NO MATTER how many there might be in the whole human population. Is this correct? Yes, of course.
And then seeing that only two genes for skin color with two alleles each is all it takes to produce 16 different skin colors... Skin color is also determined by multiple genes, at least ten.
Since we know today through genetic analysis that some genes of the human population have more than four alleles true that there have been mutations in those genes, or that there were originally more than two people, or both that there have been mutations and there were originally more than two people. Yes, and I'd been assuming that all those different alleles were proof of functioning mutations, but when it occurred to me they may not actually change anything in what the gene does I figured they aren't really functioning alleles but neutral mutations. I understand you're trying to argue that mutations cause minimal changes, but I'm making a simpler point, and it seems that you accept it. Repeating the point, any gene in the human population today that has more than four alleles (the maximum number of alleles per gene in the original human population consisting of just Adam and Eve) must have experienced mutations. Genes with many alleles must have experienced many mutations. The CFTR gene (responsible for cystic fibrosis) has over a hundred different alleles (see Alleles of CFTR; also, at the bottom of the figure is a table of mutations). --Percy
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Percy Member Posts: 22480 From: New Hampshire Joined: Member Rating: 4.8 |
Faith writes: Gary Parker showed it in a chart in "What is Creation Science?" -- the 16 different shades that result from only two genes with two alleles each. He also suggested there may be three genes for skin color but his calculation was based on two. There are many genes that contribute to skin color, see Genetics of skin color variation over at Wikipedia. More genes being involved works out better for you because of permutations. If you have just one gene A with four alleles a1, a2, a3, a4, then the number of possible permutations with two copies of the gene is 16. (a1/a1, a1/a2, a1/a3, etc...) But if you have two genes A and B, and gene A has alleles a1, a2, a3, a4 while gene B has alleles b1, b2, b3, b4, then the number of combinations is 256 (a1/a1-b1/b1, a1/a2-b1/b1, etc...). So if skin color is determined by, say, ten genes and each gene has four alleles, that's a tremendous number of possible combinations, no mutations needed for your scenario. The Wikipedia article implies that each gene for skin color has only a couple or perhaps a few alleles. --Percy Edited by Percy, : Remove incorrect paragraph. Edited by Percy, : Fix calculations.
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Percy Member Posts: 22480 From: New Hampshire Joined: Member Rating: 4.8 |
Faith writes: ...and that the original was two alleles per gene and that is enough for a great deal of variability. I think you meant to say "the original was *four* alleles per gene," two alleles from each of two original people. --Percy
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Taq Member Posts: 10038 Joined: Member Rating: 5.3
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Faith writes: The problem has always been how to explain all the variation we see without a lot of alleles in the population, and if there are all those alleles, as there are in some cases, where did they come from since Adam and Eve could have had a maximum of four. Your first hurdle would be the fact that for many genes there are more than four alleles for a given gene. If your model requires just four alleles then it is a non-starter since it is falsified by reality.
And that made me start thinking down the line of how the extra alleles have to be mutations, most of which probably don't change what the gene does. The fact that single base sequence differences are responsible for the functional differences between alleles is a serious problem for your model. You have argued that genetic diversity can only go in one direction, from high diversity to low diversity. In your model we could start with many skin colors, and then through natural selection end up with a single allele for a single skin color which is a loss in genetic diversity. However, if all it takes is a difference at one base in a specific gene then it is a certainty that a mutation will produce an individual with a different skin color in that population. There is nothing to stop this from occurring. Therefore, natural selection can reduce genetic diversity, but mutations are always increasing genetic diversity.
Well, you are one of the guys who studies genetics, and apparently what all the extra alleles do is not known by you either. Then how can you say that there are only two functional alleles per gene?
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Faith  Suspended Member (Idle past 1465 days) Posts: 35298 From: Nevada, USA Joined: |
Your first hurdle would be the fact that for many genes there are more than four alleles for a given gene. If your model requires just four alleles then it is a non-starter since it is falsified by reality. To be clear, the conclusion I've come to is that just TWO alleles per gene is all it takes to produce all the diversity we see, not four, especially where there is more than one gene per trait, and even more especially where there were a lot more living genes, that are now junk DNA. I was trying to account for all those extra alleles until I realized they aren't needed for diversity. Although bluegenes has shown a few -- or just two? -- examples where they do actually produce a new phenotype, the odds are good that most of them are just mutations, neutral mutations, that do nothing at all for the organism except manage not to screw it all up so far.
The fact that single base sequence differences are responsible for the functional differences between alleles is a serious problem for your model. You have argued that genetic diversity can only go in one direction, from high diversity to low diversity. In your model we could start with many skin colors, and then through natural selection end up with a single allele for a single skin color which is a loss in genetic diversity. That's possible under extreme conditions, yes, but it would take something like wiping out the earth with a nice collection of nuclear bombs and in that case a lot more than varieties of skin color would be lost. Perhaps a single small group of Inuit near the North Pole might survive? Which wouldn't be the best outcome because they are already subject to a lot of genetic disease but anyway. As I do keep arguing, the way genetic diversity is lost is by isolation of a group from the rest of the population. This produces new phenotypes -- this is in fact what evolution really is, the production of new phenotypes through the loss of genetic diversity, that's why "evolution defeats evolution." You'll get a new race by this process, new races of animals, new varieties of plants, but in every case by losing genetic diversity. Natural selection does this, as does domestic/artificial selection, but the most common way it happens in the wild is probably migration and geographic isolation of a new population. {ABE: This happens where evolution is actively occurring, remember, where some smallish number of individuals have become isolated from the rest of the population, but the genetic diversity that is lost in that evolving population is not necessarily lost to the rest of the population. It's where evolution is actively occurring that it is lost. Hybridization restores it, the reuniting of formerly separated populations will restore it. It won't increase it but it will restore it. And there can be many evolving popualtions at the same time, each producing a new species or phenotype while losing the alleles that don't support that phenotype. /ABE} As long as different races keep mixing together the genetic diversity is kept high. It's reproductive isolation that brings about the loss of genetic diversity. And while this is a bad thing in our fallen world I think it must be the normal method of variation that was originally built into every living thing, which would have been fine if death had never come to the world.
However, if all it takes is a difference at one base in a specific gene then it is a certainty that a mutation will produce an individual with a different skin color in that population. There is nothing to stop this from occurring. OK, but how often does this happen? Mutations are accidents of replication, right? I gather that some sequences are more prone to them than others, but most mutations are not a good thing, in most cases "neutral," or at least not changing the function of the allele, but a truly beneficial change? How often? Not often enough to save the cheetah that's for sure. So why would it be often enough to save the human race? Or even a skin color? And if you do get such a beneficial change, say you get a different skin color in the population OK, but it won't be a novel skin color. Seems to me the best that could happen is that a formerly lost allele would be accidentally reproduced by mutation and bring back a lost skin color. But new colors? You'd have to show this has ever happened.
Therefore, natural selection can reduce genetic diversity, but mutations are always increasing genetic diversity. This is an article of faith more than a reality though. You'd have to show that all those alleles bluegenes says exist in the immune system actually do something to protect the immune system in different ways, but as bluegenes talks about it it appears to be wishfully assumed but not demonstrated. On the other hand, natural selection and other events that reduce genetic diversity take their toll very rapidly, in a matter of a few generations. But even with the known proliferation of mutations how often is even one beneficial mutation demonstrable? What if they really are accidents that do far far more harm than they could ever do the slightest good?
Well, you are one of the guys who studies genetics, and apparently what all the extra alleles do is not known by you either. Then how can you say that there are only two functional alleles per gene? I'm hypothesizing. I just recently changed my mind from the multiple-allele position to the two-allele position based on the fact that the eye color gene has two, and that you can get the whole range of skin colors with two genes with two alleles each, and that mutations at best don't change the function of an allele so even having hundreds of them isn't beneficial. Edited by Faith, : No reason given. Edited by Faith, : No reason given.
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Taq Member Posts: 10038 Joined: Member Rating: 5.3
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To be clear, the conclusion I've come to is that just TWO alleles per gene is all it takes to produce all the diversity we see, not four, especially where there is more than one gene per trait, and even more especially where there were a lot more living genes, that are now junk DNA. That would be a hypothesis, not a conclusion.
I was trying to account for all those extra alleles until I realized they aren't needed for diversity. What evidence led you to that realization? What combination of human alleles will produce a cat, or a chimp?
As I do keep arguing, the way genetic diversity is lost is by isolation of a group from the rest of the population. This produces new phenotypes -- this is in fact what evolution really is, the production of new phenotypes through the loss of genetic diversity, that's why "evolution defeats evolution." You'll get a new race by this process, new races of animals, new varieties of plants, but in every case by losing genetic diversity. Natural selection does this, as does domestic/artificial selection, but the most common way it happens in the wild is probably migration and geographic isolation of a new population. That doesn't change the fact that mutations can produce new phenotypes.
OK, but how often does this happen? Mutations are accidents of replication, right? Each person is born with 50 mutations. With a 3 billion base haploid genome and 3 possible changes at each base that is 9 billion possible substitution mutations. 9 billion mutations divided by 50 is 180 million. So it takes 180 million births to get every possible substitution mutation in the human genome. If the mutation involves a mutation at the 3rd base in a codon and there is 3rd base wobble then it would take even fewer mutations to produce the same mutation in the protein sequence. With the current human population, this mutation should be occurring nearly every year.
And if you do get such a beneficial change, say you get a different skin color in the population OK, but it won't be a novel skin color. Seems to me the best that could happen is that a formerly lost allele would be accidentally reproduced by mutation and bring back a lost skin color. That would still be an increase in genetic diversity due to mutation.
But even with the known proliferation of mutations how often is even one beneficial mutation demonstrable? They are demonstrated every time we compare the genomes of two different species. The mutations that are beneficial to humans are among those that separate us from chimps. Edited by Taq, : No reason given. Edited by Taq, : No reason given.
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Faith  Suspended Member (Idle past 1465 days) Posts: 35298 From: Nevada, USA Joined: |
To be clear, the conclusion I've come to is that just TWO alleles per gene is all it takes to produce all the diversity we see, not four, especially where there is more than one gene per trait, and even more especially where there were a lot more living genes, that are now junk DNA. That would be a hypothesis, not a conclusion. Fine, but it's a new hypothesis for me, a new conclusion in relation to my former position.
I was trying to account for all those extra alleles until I realized they aren't needed for diversity. What evidence led you to that realization? The evidence is all in the reasoning. The fact that you can get two different eye colors from one gene with two alleles, and eight different skin colors from two genes with two alleles each. Any traits governed by more than one gene would have a lot of variability with only two alleles per gene. And greater heterozygosity (genes with two different alleles) in former times along with a larger number of functioning genes (before they died and became "junk DNA") would produce a LOT of variation down the generations from there. What I realized is that variation is more about having many different possible combinations than it is about specific alleles for specific effects. Three genes for eye color, three for skin color, three for any other traits you want to name, in all their many possible combinations, would produce an enormous range of variation, new races/varieties/species too. (As I've been looking at the pages in that creationist book I mentioned I realize that Gary Parker spelled this out very clearly, the same thing I've been trying to say for years. And he didn't get sidetracked by the idea of many alleles as I did either, he recognized all the way back in 1982 that two alleles per gene plus more than one gene per trait, and migration/isolation is all it takes to produce a great range of diversity in any creature. I don't think he mentions junk DNA but all the rest is there.)
What combination of human alleles will produce a cat, or a chimp? That hits me as a very silly question. Why do you ask it?
As I do keep arguing, the way genetic diversity is lost is by isolation of a group from the rest of the population. This produces new phenotypes -- this is in fact what evolution really is, the production of new phenotypes through the loss of genetic diversity, that's why "evolution defeats evolution." You'll get a new race by this process, new races of animals, new varieties of plants, but in every case by losing genetic diversity. Natural selection does this, as does domestic/artificial selection, but the most common way it happens in the wild is probably migration and geographic isolation of a new population. That doesn't change the fact that mutations can produce new phenotypes. Can. But only as an accident, a fluke, and so rarely as to be of no use to the organism. Besides which, again, this is far more an article of faith than it is a demonstrated reality. And meanwhile mutations are known to have produced thousands of genetic diseases, and in the best scenarios they simply don't change anything.
OK, but how often does this happen? Mutations are accidents of replication, right? Each person is born with 50 mutations. With a 3 billion base haploid genome and 3 possible changes at each base that is 9 billion possible substitution mutations. 9 billion mutations divided by 50 is 180 million. So it takes 180 million births to get every possible substitution mutation in the human genome. If the mutation involves a mutation at the 3rd base in a codon and there is 3rd base wobble then it would take even fewer mutations to produce the same mutation in the protein sequence. With the current human population, this mutation should be occurring nearly every year. You say all that as if it were a good thing. I can't see mutations as a good thing at all. Mostly neutral, secondly deleterious and very very rarely as a fluke maybe beneficial, usually in a way that piggybacks on something else like the sickle cell trade-off. I think all those mutations are bad for us, disease processes that over time will accumulate into actual diseases.
And if you do get such a beneficial change, say you get a different skin color in the population OK, but it won't be a novel skin color. Seems to me the best that could happen is that a formerly lost allele would be accidentally reproduced by mutation and bring back a lost skin color. That would still be an increase in genetic diversity due to mutation. Yes, but what are the odds you'll even get that? Mutations are accidents, the beneficial effects have to be rare flukes.
But even with the known proliferation of mutations how often is even one beneficial mutation demonstrable? They are demonstrated every time we compare the genomes of two different species. The mutations that are beneficial to humans are among those that separate us from chimps. But this is only an assumption based on your acceptance of the ToE, it has not been demonstrated. You assume mutations are the explanation for the differences, you haven't proved it at all, it's just that the theory tells you this is how it happens. It's all theory, no evidence. Edited by Faith, : No reason given.
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PaulK Member Posts: 17825 Joined: Member Rating: 2.2 |
quote: You do realise that all that is pure abstract theorising which doesn't take into account what the genes actually do ? In reality skin colour - and eye colour - are not that simple. Your ideas about what might be needed can't overrule what is actually there.
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Faith  Suspended Member (Idle past 1465 days) Posts: 35298 From: Nevada, USA Joined: |
Tis indeed all abstract, but so is the ToE, so is the claim that mutations are the source of variation, and in that case not just abstract but pure wishful thinking. There is no need to conjure with all the complications and details of genetic inheritance, Mendel demonstrated how it works just fine, which applies to eye color and skin color just fine.
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PaulK Member Posts: 17825 Joined: Member Rating: 2.2
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quote: Aside from the fact that we KNOW of variations produced by mutation ? And given the difficulty of proving that, there must be many more that are not provable. That is not abstract theorising, and certainly not wishful thinking.
quote: I see there is no need to actually investigate the facts. Abstract theorising and wishful thinking are the way to go. That is really a very impressive - and obvious - example of the standard creationist trick of falsely attributing their flaws to their opponents.
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Taq Member Posts: 10038 Joined: Member Rating: 5.3
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Faith writes: Fine, but it's a new hypothesis for me, a new conclusion in relation to my former position. A conclusion would require a testable hypothesis and supporting evidence, neither of which you have at the moment. It seems that you have the beginnings of a hypothesis. Now you just need to figure out how to test it and how it could be falsified.
The evidence is all in the reasoning. The fact that you can get two different eye colors from one gene with two alleles, and eight different skin colors from two genes with two alleles each. That doesn't compute. Just because skin color may need only two alleles does not mean that other characteristics don't need more. You can't take one example and claim it is true for the rest of the genome.
And greater heterozygosity (genes with two different alleles) in former times along with a larger number of functioning genes (before they died and became "junk DNA") would produce a LOT of variation down the generations from there. How did you determine that the hundreds of thousands of human pseudogenes were functional in the recent past? What evidence, if found, would falsify your hypothesis that human pseudogenes were active just a few thousand years ago?
Three genes for eye color, three for skin color, three for any other traits you want to name, in all their many possible combinations, would produce an enormous range of variation, new races/varieties/species too. This is what led me to this question: "What combination of human alleles will produce a cat, or a chimp?" If a combination of human alleles can not produce a cat or a chimp, then how do we have cats and chimps? You seem to be saying that a human could give birth to a cat simply by a combination of human alleles already found in the mother and father. If that isn't the case, then why are cats different from humans? If human alleles are not capable of producing the biodiversity we see, then what is producing it?
Can. But only as an accident, a fluke, and so rarely as to be of no use to the organism. Besides which, again, this is far more an article of faith than it is a demonstrated reality. And meanwhile mutations are known to have produced thousands of genetic diseases, and in the best scenarios they simply don't change anything. If the alleles are currently of use to humans, then why wouldn't they be of use when they are produced by mutations? Also, mutations aren't an article of faith. We can watch them happen. They are a fact. Why in the world would you claim that mutations don't happen?
You say all that as if it were a good thing. I can't see mutations as a good thing at all. Mostly neutral, secondly deleterious and very very rarely as a fluke maybe beneficial, usually in a way that piggybacks on something else like the sickle cell trade-off. I think all those mutations are bad for us, disease processes that over time will accumulate into actual diseases. If the human genome can't be changed without causing disease, then how can other species survive with all of these differences? When we compare chimps and humans we find 40 million mutations separating them. How are chimps able to survive, disease free, with so many mutations?
Yes, but what are the odds you'll even get that? Mutations are accidents, the beneficial effects have to be rare flukes. Winning the lottery is also a fluke of luck, yet it happens all of the time.
But this is only an assumption based on your acceptance of the ToE, it has not been demonstrated. You assume mutations are the explanation for the differences, you haven't proved it at all, it's just that the theory tells you this is how it happens. It's all theory, no evidence. If the DNA sequence differences are not responsible for the physical differences between species, then what is?
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