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Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
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Author | Topic: MACROevolution vs MICROevolution - what is it? | |||||||||||||||||||||||||||||||||||||||
PaulK Member Posts: 17827 Joined: Member Rating: 2.3
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quote: Lies aren't facts. Because mutations will continue to arrive even IF a species ran out of variety it would not be doomed to stop evolving. If your car runs out of fuel you can put a little more in and drive that bit further. Even more, if the tank is continually being topped up at the same rate as fuel is used you won't run out in the first place. When your own analogy proves that your assertion is silly and wrong it really is time to give up.
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dwise1 Member Posts: 5952 Joined: Member Rating: 5.2
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I think it's a false analogy. That's right! And so is yours for the same reason. It's not just the engine accelerating the car and it's not just friction decelerating it, but rather it's the net effect of both forces considered together. It's not just the accumulation of genetic diversity and it's not just the loss of some of that genetic diversity through selection, but rather it's the net effect of both forces considered together. If you only consider the one factor while ignoring the other, as you are doing, then you arrive at incorrect conclusions, often at ridiculously incorrect conclusions. BTW, in your model, how are neutral mutations lost through selection? How does selection eliminate them, given that selection does not act upon them, what with them being neutral and all that? And keep in mind that today's neutral mutation can be tomorrow's beneficial trait when the environment changes.
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Faith  Suspended Member (Idle past 1472 days) Posts: 35298 From: Nevada, USA Joined: |
Again, you'd never ever get an identifiable species or variety or breed or race if beneficial mutations kept occurring in the sex cells at the rate necessary to stop the loss of genetic diversity that is NECESSARY to the formation of species or varieties or breeds or races.
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Taq Member Posts: 10081 Joined: Member Rating: 5.1 |
Faith writes: Again, you'd never ever get an identifiable species or variety or breed or race if beneficial mutations kept occurring in the sex cells at the rate necessary to stop the loss of genetic diversity that is NECESSARY to the formation of species or varieties or breeds or races. If that were true, then every species would be homozygous for a single allele for every gene. This isn't the case.
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dwise1 Member Posts: 5952 Joined: Member Rating: 5.2 |
The point is that adding mutations is like adding fuel to an engine. Unless the fuel is used up the engine isn't running, you aren't getting evolution. I have been driving since 1967, so then for half a century. You are claiming that I should have run out of gas long ago, yet I still have never run out of gas. Never, not even once.
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PaulK Member Posts: 17827 Joined: Member Rating: 2.3 |
quote: You say that but without the numbers it's just an empty assertion contradicted by the evidence. We don't see your "inevitable" depletion of diversity despite all the evolution that - according to the evidence - has occurred. Especially as we don't need the mutations to be beneficial to top up diversity. (If losing an allele is a loss of diversity then gaining it would be an increase in diversity - thus if losing a detrimental allele is a loss of diversity even a detrimental mutation is an increase) You would think that in all these years of trying to argue this you would have come up with some rational reason to believe it. But all you have is an opinion that seems obviously false. That is not a winning argument.
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Faith  Suspended Member (Idle past 1472 days) Posts: 35298 From: Nevada, USA Joined: |
For the evolution of a new variety or race or breed or species to occur you HAVE to lose genetic diversity, the genetic substrates of the new phenotypes have to displace those of whatever is being replaced. You can only get a population of salamanders with distinctive markings by isolating them from their founding from the other populations of salamanders, and that causes the loss of the genetic material for the markings of the former population. That's how domestic breeding has often occurred too, by simply isolating the animals with the desired traits from the others until the genes for the new traits become homozygous. The original breeds of cattle must have developed from the isolating of small numbers from the wild herd to form domesticated herds, which over time developed the distinctive characteristics brought about by the new gene frequencies brought about by their isolation from other characteristics in the original herd. Dozens, even hundreds, of different breeds of cattle could be formed by this simple process, each new herd developing its own set of traits while LOSING all the genetic stuff for all the other traits. You get a Greyhound by losing all the genetic stuff for the traits of huskies and Chihuahuas and so on and so forth. If those alleles remained in the population you would not have the breed at all.
There is no combining the addition of traits with the reduction of traits. That makes no sense. As I understand it, a neutral mutation is simply a mutation that does not change the protein produced at that locus, therefore doesn't change the phenotype. And a changed phenotype would have to spread through the population to have a part in forming a new species or breed etc. That spreading would be the result of some form of selection, something that favors that phenotype, and if it spreads then it will contribute new characteristics to the new population. As I keep pointing out, if you keep getting [beneficial selected germ cell] mutations eventually you lose your species or breed. But species persist pretty reliably in nature. Some breeds have to be artificially preserved by enforced reproductive isolation but it is that isolation that keeps such identifiable populations identifiable and intact, protecting them from the gene flow that would destroy their recognizability. Gene flow, addition, destroys an established breed or species. Not tnat nature cares, of course, but it doesn't seem to happen the way all this adding-subtracting theorizing says it should. Addition could only be basic fuel, after that it is an interference with the formation of a species, breed etc. Edited by Faith, : No reason given. Edited by Faith, : No reason given.
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Faith  Suspended Member (Idle past 1472 days) Posts: 35298 From: Nevada, USA Joined: |
yes, cars can always replenish their fuel and keep going, that's why tht is not a good analogy for evolution.
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PaulK Member Posts: 17827 Joined: Member Rating: 2.3 |
It is a bad analogy because it accurately represents the situation? What an odd idea!
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Faith  Suspended Member (Idle past 1472 days) Posts: 35298 From: Nevada, USA Joined: |
Again, you'd never ever get an identifiable species or variety or breed or race if beneficial mutations kept occurring in the sex cells at the rate necessary to stop the loss of genetic diversity that is NECESSARY to the formation of species or varieties or breeds or races. If that were true, then every species would be homozygous for a single allele for every gene. This isn't the case. Homozygosity at many loci is the inevitable end result if selection persists, but I'm talking about a trend, there always being some loss of genetic diversity with the formation of a new population with its own identifiable characteristics, SOME homozygosity with each new population, the extreme condition of fixed loci for all traits wouldn't occur. New combinations based on a new set of gene frequencies is going to bring out new traits no matter what. In the ideal ring species you probably don't get a lot of fixed loci until after many new populations have formed, but you do get new phenotypes from loss of genetic diversity all along the way. If this much could be established I'd be interested in hearing about what this lookis like genetically, but as long as the basic scenario is being denied there's no way to discus it. For instance I figure the black wildebeest population which is enormous, a million or more, has great genetic diversity and that its characteristics are maintained by free breeding among its members though the percentage of homozygosity in the genome may be fairly low by comparison to a species formed from a small number of individuals. There are at least two other populations of wildebeests, one called the blue wildebeest, which probably formed from some number that migrated away from the majority black herd. Whichever migrated away should show the greater loss of genetic diversity, which usually means some increase in homozygosity, but I wouldn't expect it to be severe unless the founding population was really small. Edited by Faith, : No reason given. Edited by Faith, : No reason given.
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Taq Member Posts: 10081 Joined: Member Rating: 5.1
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Faith writes: For the evolution of a new variety or race or breed or species to occur you HAVE to lose genetic diversity, You also have increases in genetic diversity due to mutations.
You can only get a population of salamanders with distinctive markings by isolating them from their founding from the other populations of salamanders, and that causes the loss of the genetic material for the markings of the former population. There are no two salamanders that are going to be exactly alike. The genes responsible for those markers are going to have multiple alleles in the population. There are also going to be many alleles for the genes that are not responsible for those markings. Your supposed distinct populations just don't exist.
There is no combining the addition of traits with the reduction of traits. That makes no sense. That's exactly what happened in the example of the pocket mice. Selection pressures caused all of the mice to be light brown in color. After the population of all light brown mice were established a few volcano eruptions occurred which produced dark black basalt in a few areas in the desert. Mutations in those light brown mice produced black mice, and when those black mice found themselves on the black basalt rocks that trait was selected for. Now you have a mixture of black and light brown mice, an increase in genetic diversity that runs counter to everything you are claiming.
As I understand it, a neutral mutation is simply a mutation that does not change the protein produced at that locus, therefore doesn't change the phenotype. That is false. What you are describing is a synonymous mutation which are thought to be largely neutral. However, changes in the protein sequence of a gene can change the phenotype, but those changes can still be neutral. There are probably mutations in some genes that affect nose length in humans, but the differences caused by those mutations are neutral with respect to fitness.
As I keep pointing out, if you keep getting [beneficial selected germ cell] mutations eventually you lose your species or breed. We call this evolution. We are saying that species change over time due to the accumulation of mutations and selection.
But species persist pretty reliably in nature. Then show me an organism from the species Australopithecine afarensis, or Homo erectus.
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Taq Member Posts: 10081 Joined: Member Rating: 5.1 |
Faith writes: Homozygosity at many loci is the inevitable end result if selection persists, but I'm talking about a trend, there always being some loss of genetic diversity with the formation of a new population with its own identifiable characteristics, SOME homozygosity with each new population, the extreme condition of fixed loci for all traits wouldn't occur. And I am saying that mutations continue to occur at every loci, and those mutations accumulate. While one loci may be under selection, other loci are not and they continue to diversify. Even the loci under selection are mutated, and new more beneficial alleles can arise from them and be selected for. It never stops.
In the ideal ring species you probably don't get a lot of fixed loci until after many new populations have formed, but you do get new phenotypes from loss of genetic diversity all along the way. You also get new phenotypes from mutations. Edited by Taq, : No reason given.
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Taq Member Posts: 10081 Joined: Member Rating: 5.1 |
Faith writes: yes, cars can always replenish their fuel and keep going, that's why tht is not a good analogy for evolution. It's a good analogy because mutations are the fuel of evolution, and that fuel is continually replenished.
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Tanypteryx Member Posts: 4444 From: Oregon, USA Joined: Member Rating: 5.1 |
As I understand it, a neutral mutation is simply a mutation that does not change the protein produced at that locus, therefore doesn't change the phenotype. Your understanding is incorrect. A neutral mutation is neutral with respect to fitness. It may change the phenotype, but not every change in the phenotype has a positive or negative effect on fitness or is subject to selection.
And a changed phenotype would have to spread through the population to have a part in forming a new species or breed etc. That spreading would be the result of some form of selection, something that favors that phenotype. The genes for the change in phenotype can spread through drift and they may never reach a large proportion of the population. Almost all populations consist of individuals that are not identical genetically or phenotypically. The individuals that make up the population have many thousands of traits that each vary with gaussian-type distributions.
As I keep pointing out, if you keep getting mutations eventually you lose your species or breed. In this case breeds and species are not similar because breeding has a goal of creating purebreds. Nature has no goal of "pure species", and as is observed, species vary greatly in thousands of traits and mutations keep adding variety in every surviving individual in every generation. I note surviving individuals because obviously lethal mutations are eliminated. Often detrimental mutations are not passed on or are passed on to fewer offspring. Highly beneficial mutations may eventually reach fixation in a population, but most mutations, even beneficial ones are at lower proportions in the population.
Some breeds have to be artificially preserved by enforced reproductive isolation but it is that isolation that keeps such identifiable populations identifiable and intact, protecting them from the gene flow that would destroy their recognizability. And again, this may apply to selective breeding, but there is no biological boundary protecting natural populations from the gene flow that would destroy their recognizability. Billions of years of fossil evidence and observations of the living species in the present demonstrate that despite millions of species going extinct, millions of species survive and continue to evolve on the Earth today.What if Eleanor Roosevelt had wings? -- Monty Python One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy The reason that we have the scientific method is because common sense isn't reliable. -- Taq
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Faith  Suspended Member (Idle past 1472 days) Posts: 35298 From: Nevada, USA Joined: |
Not in any way that contributes to the formation of new species, races, varieties, breeds, etc., which requires some form of selection which requires losing genetic diversity. And if it did keep doing what you claim, you would never have any identifiable species, races, varieties or breeds.
Edited by Faith, : No reason given.
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