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Member (Idle past 1406 days) Posts: 20714 From: the other end of the sidewalk Joined: |
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Author | Topic: MACROevolution vs MICROevolution - what is it? | |||||||||||||||||||||||||||||||||||||||||||
Faith  Suspended Member (Idle past 1445 days) Posts: 35298 From: Nevada, USA Joined: |
Of course it destroys your assertion that the loss of variation must end evolution. That can't happen. Anybody who honestly thinks it through should recognize that the loss of genetic diversity brought about by the processes of microevolution that produce new varieties, races and species, has to bring evolution to an end. However selection is expressed in Dawkins' model is false. Watch the program work, it just produces one variation after another as if it had infinite resources.
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Tangle Member Posts: 9489 From: UK Joined: Member Rating: 4.8
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Faith writes: That can't happen. And yet it does! So, when confronted with a disproven hypothesis, what does the honest scientist do?
Anybody who honestly thinks it through should recognize that the loss of genetic diversity brought about by the processes of microevolution that produce new varieties, races and species, has to bring evolution to an end. And yet it hasn't! So, when confronted with a disproven hypothesis, what does the honest scientist do?Je suis Charlie. Je suis Ahmed. Je suis Juif. Je suis Parisien. I am Mancunian. I am Brum. I am London. "Life, don't talk to me about life" - Marvin the Paranoid Android "Science adjusts it's views based on what's observed.Faith is the denial of observation so that Belief can be preserved." - Tim Minchin, in his beat poem, Storm.
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PaulK Member Posts: 17822 Joined: Member Rating: 2.2 |
quote: As I pointed out it DOES happen. You can get antibiotic resistance evolving from a clonal population of bacteria.
quote: Your "honest thinking" seems to be nothing of the sort. But please demonstrate it to us.
quote: The production of variation has nothing to do with selection. And the production of new variation IS realistic (and need I point out that since the length stays the same - unlike real evolution - the number of possible variations is clearly finite?)
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Faith  Suspended Member (Idle past 1445 days) Posts: 35298 From: Nevada, USA Joined: |
1) The Pod Mrcau lizards are a very unusual case. Taking such cases as typical is an obvious mistake And what example would you put forward as typical?
2) We do not know the basis of the phenotypic changes in the lizards - it may be partly (or even wholly) an environmental response which would be much quicker. Just normal sexual recombination over generations is the simplest explanation, bringing out the large heads and jaws simply due to their genes being high frequency in the original population, purely randomly. If a dozen human beings get isolated on an island for a few hundred years some striking traits are likely to come to characterize the whole population after that time just because of the recombination of the genes possessed by the original dozen. An environmental response should in reality be much slower if the large headed adaptation was rare in the original group, and in fact not even expressed phenotypically, since the unadapted lizards would be living with a major handicap until it became high frequency. In fact this scenario could involve great loss to the population until the adapted form spreads, and that would mean even greater loss of genetic diversity than the scenario I'm assuming as all the possessors of low frequency genes would rapidly disappear and not be part of the reproducing few. In my scenario all are capable of reproduction, the same food supply is available on the island as the mainland where the parent population continues to live, a large head and jaws shows up purely by sexual recombination over a few generations and eventually spreads through the whole population, determining the choice of food rather than the other way around.
3) We do not know if the lizards would interbreed with the ancestral species - and we do know that Jutland cattle CAN interbreed with other cattle. So we cannot say that either represents full speciation. I'm not interested in "full speciation," merely the fact that recognizable phenotypic changes fairly rapidly result from simple random selection of a small number of individuals out of a larger population, showing that simple sexual recombination of a new set of gene frequencies is all it takes to get a new variety. If "full speciation" has not yet arrived, it will eventually if reproductive isolation continues. It also should show that developing new phenotypes requires genetic loss because the traits in one subpopulation are different from those in the others. Edited by Faith, : No reason given. Edited by Faith, : No reason given.
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PaulK Member Posts: 17822 Joined: Member Rating: 2.2
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quote: I would be looking at examples considered incipient species, or maybe introduced animals on other islands. Remember that the lizards got a lot of attention because the change was so dramatic. Do you have any other examples of such dramatic change over so short a time ?
quote: Or maybe if the young lizards have to work harder to chew their food the head and jaws develop more. I don't think we can say.
quote: Any examples to support that claim ? I very much doubt that it would be as dramatic as the lizards.
quote: We don't know whether the lizards are an example of that or not. You'd be better with your examples of domestic breeding. Although full speciation IS important because otherwise your new variety could just be absorbed back into the main population if the geographic barriers ceased to be a factor.
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Faith  Suspended Member (Idle past 1445 days) Posts: 35298 From: Nevada, USA Joined: |
I would be looking at examples considered incipient species, or maybe introduced animals on other islands. Well until you can come up with one you don't have much of an argument.
Remember that the lizards got a lot of attention because the change was so dramatic. It was only so dramatic because it contradicted evo expectations, not because there is any evidence in reality that supports those expectations.
Do you have any other examples of such dramatic change over so short a time ? The Jutland cattle seem to fit. Even the record of breeds that only take a hundred years or so to develop from wild stock to pure bred, as in many cattle breeds. Any founder effect will fit of course and I do regard those as species. The circumstances are unusual which is why the ToE fantasy can go on unchallenged. But these few examples ought to be a challenge, even the lizards alone, especially in the absolute absence of any contrary evidence.
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Faith  Suspended Member (Idle past 1445 days) Posts: 35298 From: Nevada, USA Joined: |
Although full speciation IS important because otherwise your new variety could just be absorbed back into the main population if the geographic barriers ceased to be a factor. Not important at all since just getting a clearly identifiable new variety demonstrates that the changes do not require anywhere near the time the ToE assumes. And surely it is obvious that because the population started from such few numbers there should be a great deal of homozygosity in the genome, meaning severely reduced genetic diversity. If this is doubted then DNA should be tested.
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PaulK Member Posts: 17822 Joined: Member Rating: 2.2
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quote: I'll settle for a weak argument if it's stronger than yours - and it is.
quote: If such changes commonly happened in such a time it would hardly be considered dramatic. Breeders should be able to manage it on a routine basis. This is evidence in reality to contradict your claim.
quote: What on earth are you talking about ? Which cattle breeds were developed from wild stock on only a hundred years ? And why regard breeds as species ? What are the dramatic differences ?
quote: The problem is the lack of any evidence. We can't tell if you are right or not - and the absence of other examples is a big problems for you.
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PaulK Member Posts: 17822 Joined: Member Rating: 2.2 |
quote: If we are considering the time required for speciation then speciation is obviously important. And that is the time you are talking about.
quote: Nobody is doubting that. Although the relationship to the phenotypic changes is in doubt. It should be obvious, for instance, that none of the lizards brought to the island displayed the new phenotype.
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Faith  Suspended Member (Idle past 1445 days) Posts: 35298 From: Nevada, USA Joined: |
It should be obvious, for instance, that none of the lizards brought to the island displayed the new phenotype. Yes that is obvious, but so is it obvious that none of Darwin's pigeons started out with their exaggerated characteristics. They came about through a series of selected matings, showing that the potential was originally in the genome though unexpressed. This is in fact an argument for the effect of sexual recombination over generations of the genetic material in the original small number of individuals, as opposed to mutations or environmental pressure etc.
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PaulK Member Posts: 17822 Joined: Member Rating: 2.2 |
quote: Which means that selection is required in addition, and quite strong selection IF the differences are due to genetics. That is one of the reasons for suspecting environmental response as at least a partial cause of the differences - that would skip the need for selection and work much quicker.
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Faith  Suspended Member (Idle past 1445 days) Posts: 35298 From: Nevada, USA Joined: |
= Yes that is obvious, but so is it obvious that none of Darwin's pigeons started out with their exaggerated characteristics. Which means that selection is required in addition, and quite strong selection IF the differences are due to genetics. We already have pretty strong selection in the fact that only ten individuals made up the founding population so that there was a very small gene pool undergoing recombination over the generations. No further selection is needed since the genetic stuff for the larger heads was in that gene pool to begin with, and probably in more than one individual, so that recombination itself would have been enough to bring that characteristic to expression -- and increase it from generation to generation too, as Darwin increased the odd traits of his pigeons. In other words limited mating opportunities from a genetic standpoint could be sufficient selection to bring out the trait. There could have been some additional form of selection as well, but my point is it wouldn't have been needed given the founding numbers.
That is one of the reasons for suspecting environmental response as at least a partial cause of the differences - that would skip the need for selection and work much quicker. I'm not following your reasoning. First, the small number of founding individuals is already strong selection of a very small gene pool, and second, what can you mean by "environmental response" if not selective pressure from the environment? Either way you've got selection in operation. Edited by Faith, : No reason given.
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PaulK Member Posts: 17822 Joined: Member Rating: 2.2 |
quote: That would only be true if the ten were chosen because they already had the "new" features - and they didn't. So, no, there was NO selection there. Instead of boasting about your "simple logical argument" or claiming that "honest thought" would show that you were right you might like to spend some time actually thinking about the issues. Maybe you would make fewer ridiculous errors.
quote: As I have already pointed out your first claim is nonsense. On the second point I mean that the lizards may grow differently becUse of the different environment - no genetic change required. That does fit the very rapid change without selection for the new features which you seem to think can be accomplished by selecting individuals without any of them.
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Faith  Suspended Member (Idle past 1445 days) Posts: 35298 From: Nevada, USA Joined: |
Sorry, the word "selection" doesn't have to mean it has a purpose, it is certainly random selection when a particular small number of individuals is reproductively isolated, because only the genetic material from that small group becomes the foundation of the characteristics of the population that eventually emerges.
If you make a pile of small objects and take a random handful out of the pile to put to use, you've selected that handful in the sense I'm using the term. Or randomly drawing a few tickets out of the pool for a lottery is the same kind of selection. It is descriptive of the common event of forming a daughter population from a limited number of individuals, often brought about by migration away from the parent population, but also formed within a population by drift and so on. You might withhold your insults until you understand the situation. Edited by Faith, : No reason given. Edited by Faith, : No reason given.
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PaulK Member Posts: 17822 Joined: Member Rating: 2.2 |
quote: I didn't assume a purpose. But there must be some causal reason why those individuals were selected relating to the features in question. And there is not.
quote: That is drift, not selection.
quote: Unfortunately for you, you were responding to my use of the term, and I was using it correctly. And if you had thought about it you would understand that actual selection for the new features was required after the lizards arrival.
quote: You might learn to stop equating criticism with insult. And since I did and do understand the situation you have no point here at all.
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