What is the mechanism that prevents microevolution to become macroevolution?

I have to partially disagree. While Faith would certainly be entitled to ask for further explanation, even a layman should be able to work out that the papaer does address the genetic evidence:These are the 3rd and 4th sentences from the abstract: While a layman might struggle with the technical words I cannot see how they could read "We examine how these genetic data..." and come to the conclusion that the paper does not discuss the genetic data.So I do not see that Faith can be considered to be right in rejecting the paper if she is not even prepared to read the first few sentences of the abstract. Her complaint here, while not completely invalid, is something of a red herring, raised to cover the fact that she is dismissing a source without even a cursory investigation of its contents.t

I don't see how this is supposed to help your argument in any of the points under dispute. The fact that the bottleneck in itself has not instantly converted the isolated populations into new species in itself for instance suggests that there is something more to speciation than a bottleneck. (As should be obvious - if there were no new alleles every individual in the "new" species would have been possible in the original species)

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And if mutation were anywhere near the power claimed for it, so many species would not be on the verge of extinction as a result of becoming isolated and changing in the ways that may be called incipient speciation or outright speciation.

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But this is BEYOND the power attributed to mutation. Mutation is not credited with the power to automatically rescue populations from the immediate consequences of a depleted gene-pool. It takes time (the cheetahs are still recovering, slowly, for instance).The simple fact is that neither extinction nor salvation through mutation are inevitable in such a situation. Small isolated populations just have a harder time surviving.

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My argument is that reduction in genetic diversity is the inevitable inexorable trend of all natural processes towards speciation, and all species undergo these processes

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My point is that it can't be a loss of alleles due to splitting the population that produces speciation. So something else must be needed. Especially if you make interbreeding yoour definition of speciation. Without new alleles, all the alleles in the split populations were present in the parent population - yet it would be unusual to find much in the way of incompaitbilities in reproduction in the parent population - so why should the split populations be unable to interbreed unless new alleles that are incompatible are incorporated into one population or another ?

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Yes, they are possible in the original species, but the traits of some alleles are not expressed much or at all, and could be said to be "latent," either because they occur in very low frequency or are recessive or affected by other genetic conditions I wouldn't know a lot about.

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Rare alleles would be prime candidates to be lost. And there must be some change elsewhere to allow unexpressed features to be expressed. It doesn't seem that speciation would be very likely in your model.

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The point is just that it is very hard to get across this fact of inexorable genetic depletion through the normal processes of variation and speciation, because mutation keeps being assumed to take up the slack of this depletion. In fact it simply doesn't.

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But that has NOT been established as a fact. That is your opinion, and so far as I can tell it is based mainly on your desire for it to be true.

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Mutation has to be able to occur at a prodigious rate with prodigiously useful effects to overcome this inexorable reduction,

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You assert that, but without actual numbers it is simply an unsupported assertion. So far as I am aware there is no need for the mutation rate to be any greater than it has been measured to be.So at what rate are alleles actually being lost ? I don't want your opinion, I want a valid estimate based on real evidence. Do you have one ? If not then are you prepared to retract your assetion ?

It seems that the title is not true.Just because evolution is defined as a change in allele frequencies does not mean that all historical evolution can be accounted for simply in terms of changes in frequency without the addition of new alleles. In fact you have been presented with examples where new alleles do appear in bacterial populations. It say that a change in allele frequencies includes the case where no new alleles appear is simply not relevant. What you need is EVIDENCE that new alleles do not appear in sufficient quantity.Moreover the fact is that to explain the observed genetic diversity without accepting a significant role for mutation - which is known to occur - you have to produce a completely ad hoc explanation which to the best of my knowledge you can't even clearly explain - with no evidence at all for it.

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Thinking about mutation in this respect, however, why should that prevent interbreeding either? Mutation simply changes an allele, but if the basic gene is there in both populations why wouldn't the new allele simply combine with whatever other alleles exist in either population?

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It's an area that is being studied. However, a priori, it seems far more likely that cumulative changes could produce incompatible genomes than that there could be a huge number of genetic incompatibilities within an existing population. Moreover incompatible alleles just by being incompatible would have reduced fitness - a constraint that is only relaxed when one of the alleles is removed from the population. Thus it is hard to say that incompatibilities are likely to arise without mutation since otherwise it would require a rare allele to take over at least one of the subpopulations. Which seems less likely to me than a gradually accumulating incompatibility through mutation and drift starting after the populations split.

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Right. I lose track of what I'm trying to say sometimes. Rare alleles WOULD be more likely to be lost, that is, lost to a new population that migrated from the original.

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They are ALSO more likely to be lost through drift after the split. Because the allele is only present in small numbers it can be mmore easily lost to chance than a more established allele.

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f you would just keep mutation out of the picture for the time being and just think through the processes I'm describing, which are all standard science that evolutionists refer to all the time, you ought to be able to follow it all to the logical conclusion I keep pointing out here, which is that genetic depletion IS the overall trend in all these processes. There's nothing of opinion in this at all, it logically follows from an understanding of what these processes actually do.

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Here is the statement you were supposed to be supporting again: So you see that the questin is whether mutation can "take up the slack". You quoted this in your post do I don't see how you could have missed it. Are you really asserting that your claim that mutation cannot compensate for the loss of alleles is based on ignoring mutation ? If so you cannot call it a logical or even a rational argument.Regardless, it is true that you have not produced a valid argument or evidence to support something you are quite happy to call a "fact"

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Well, if you would just follow the argument here, you'll have to see that what presently is credited to mutation is nowhere near supplying the number of useful changes needed, that is, the number needed to rival those changes that take place in every sexual recombination, or for that matter in whole populations as allele frequencies change over time, all of which tend in the direction of decreasing genetic variability.

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Sexual recombination doesn't reduce allele frequency in itself. And without a measurement of the relative rates at which alleles are lost and gained - or at least a good estimate - there can be no valid logical argument. In short I know that I am following the argument because I have found the gaping hole in it.To get a valid answer we need to consider the actual rates at which alleles are lost and added. And you don't have any estimate of those rates. All you offer is an opinion, which you call a fact.

The fact that all the people with the allele had a relatively recent common ancestor suggests that it was that ancestor who first had that allele - i.e. that it IS a mutation. Once a mutation occurs it IS passed on as any other allele is, so I can't see why you would think that significant.

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Hardly. The most likely explanation is that that ancestor got it from his/her ancestors.

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How so ? The further you go back the more likely that the ancestor who first had the allele also would have other descendants with the gene - but none are known.

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Just that if it's a mutation, it isn't a mutation that occurred in any living individual, it has been passed down.

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As of course it would be. That is hardly evidence that it is not a mutation. Whereas the fact that it is known only in a few closel related people gives us good reason to think that it is a mutation that occurred in the relatively recent past.

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How are you going to rule out the possibility that it's merely a built-in allele that has been in the human race back to a Beginning?

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We don't HAVE to absolutely rule it out. It is enough to note that the evidence is best explained by this allele being the result of a recent mutation. Why should we accept your personal belief that it isn't, instead of following where the evidence points ?

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It isn't EVIDENCE that points there, it is merely the needs/assumptions of the ToE that point there.

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The fact that the allele is found in a relatively few individuals all with a recent common ancestor is "EVIDENCE" that points to this allele being produced by mutation.You claim that is is "more likely" that this is a rare allele which somehow managed to spread perfectly well in this one location by chance or for some unstated reason. But I see no argument for such a claim - which seems to be based instead on the "needs/assumptions" of your own position.Without looking at further evidence it seems that you don't have a good case - your argument appears to be circular. You assume that mutations make no significant contribution to genetic diversity and then rtry to rule out evidence against this assumption by begging the question - how else could you come to the conclusion that it is "more likely" that this is an old allele rather than a recent mutation ?If we did look at the allele itself we could come up with more evidence. If this allele could plausibly be formed by a single mutation of alleles found in other individuals in the area it is very likely that it is a mutation. The further form this case we get the more likely that it is a rare allele that survived. In fact it seems that the difference in the protein produced is a single amino acid
Page Not Found | OSTI.GOV A single change to one base in the DNA can produce this effect - a very small change. This is not a substitute for a full genetic analysis but it certainly indicates that this allele is well within the range available to mutation.

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OK, then think about it this way. We have these particular facts, and they can be explained reasonably in a number of ways. Your way has no more validity to it than mine does.

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Apart from the fact that my way is a more likely explanation.

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However, I gave the third scenario that assumed mutation many generations ago that first got selected in and then selected out. That would explain the known facts just as well.

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It would be a little better than your preferred explanation, but it would still have the problem that - somehow - every instance of this allele seems to come from one single person. That's inevitable for a new mutation and unlikely for either of your scenarios. And of course your third scenario is of little help for your position.

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That works both ways. You assume that mutation accounts for everything genetic, which is no less "circular" (although that term is always misused here to describe what is not circular but really inference from a theory).

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No, it doesn't work both ways. The evidence better fits a new mutation. Your argument seems to be circular because - so far as it can tell - it relies on the very assumption you are trying to defend. I'm not relying on a similar assumption.

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The chemistry involved is interesting but I see nothing in the chemical facts that shows this is a mutation rather than merely an inherited low-frequency allele that was perhaps once selected against

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If you assume that all alleles come from an original creation the fact that this is a very minor difference must be attributed to coincidence. If it is a recent mutation then it would almost have to be within easy reach of the alleles found locally. So the idea that it is a recent mutation is a better explanation of why the difference is so small.So, again, the fact is that the best explanation is that this is a recent mutation. Arguing that it "could be" something else does not change the way that the evidence points.

I thought that said that you didn't need data. That you had a logical proof that mutation couldn't produce sufficient new alleles. You certainly claimed that it was a fact that that was the case - so why are you asking for data now, when you claimed to already knwo the answer ?And perhaps you would like to produce evidence that the loss of alleles occurs at a "prodigious" rate. It is the difference between the two rates that you need to know - just knowing the rate at which mutations occur isn't much use on it's own.

The age of the Earth belongs elsewhere, but the 4.5 billion year age is a conclusion and it's certainly not the basis of any dating method used.

As I said it's off topic here. Start a new thread - and you can explain there why you thought it was an assumption underlying dating methods.

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Because that is the answer that is always given to me -- oh but we have the EVIDENCE. We SEE an increase in alleles after speciation.

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So SHOW it already. That's what I'm asking for.

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That makes no sense. You claimed that it was a fact that mutation couldn't keep up with the loss of alleles. When I pointed out that it was your opinion you objected and offered what you called a "logical argument". Which was nothing of the sort. Now you suddenly need data - which you should have had in the first place.

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I didn't say the loss occurs at a prodigious rate, I said it occurs over time as a trend of all the population-splitting and changing processes. But mutation has to catch up with it AND exceed it if it is going to be "the engine that drives evolution."

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Oh, so when you ask for data for "prodigious beneficial mutations"- see the title you wrote - you didn't mean "prodigious" OR beneficial ?And mutation only needs to exceed allele loss over the short term, to recover from a loss of allelic diversity. What we should expect to see in the long term is a dynamic equilibrium where gain and loss balance. You need to consider that the rate of loss depends on the number of alleles present - the more present the faster they will be lost.

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I am not asking for data because I want it, but because others have claimed it exists

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It still makes no sense. If your "fact" really was a demonstrable fact you wouldn't need the data. In fact you would almost certainly need the data to honestly claim that your idea WAS a fact.

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That is asking a lot of a supposedly random process, but then show that much. Bring out the numbers that prove that.

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No it isn't asking much at all. There would almost certainly have to be an equilibrium point - the randomness of the process doesn't affect that, any more than the randomness of spontaneous nuclear decay prevents us from working out highly reliable figures for the half-life of a radioactive isotope. The only question would be whethher the observed rates would be sufficient to maintain the observed diversity - and that would only be a question of average rate.

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have no idea where you get stuff like this.

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I get it from YOUR POSTS.

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I said that I don't think the LOSSES are prodigious, but I DO think mutation has to occur prodigiously beneficially to overcome the effects of the reducing processes I've described over time, and nothing anyone has said about actual mutations suggests anythign remotely like that occurs. Mutation has to exceed the losses IF evolution can possibly occur, not just maintain some balance which just keeps shuffling the status quo -- and besides if that is what happens you'd never get a new breed of animal as you do with domestic breeding, where you need to eliminate alleles.

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Firstly, in the long term a balance is all that is needed. Secondly in the short term, because most mutations vary existing genes there is no contradiction between the "reduction" needed to fix a trait and maintaining diversity. The mitochondrial Eve studies, for instance, rely on this sort of mutation in the region of DNA they studied.The only case where mutations need to supply diversity significantly quicker than it can be lost is in the case where diversity has been seriously depleted (or, maybe, in the very early history of life). o the only reaon why the overall rate of mutations would need to be "prodigious" is if the rate of loss were also "prodigious". And, of course, neutral mutations can also contribute to diversity

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But I don't even think the new alleles mutation brings about could be counted on to do anything of the sort you are saying. It's basically a random destructive process that only very occasionally makes a change that is of some use.

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And if the loss of useful alleles only happens very occasionally (as we would expect them to be positively selected for) we only need very occasional beneficial mutations. Most of the alleles lost will be neutral or detrimental as an outcome of selection.Edited by PaulK, : Faith added more to her post by edit

So lets get this straight.You claimed that it was a fact that mutation could not keep up with the allele loss that happens anyway.You reject the idea that it was just your opinion.Yout "logical argument" rested on ignoring mutation.And now you're asking the other side to come up with data ?
So what you are saying is that you can call your opinions facts - and even deny that they are just opinions - without knowing the numbers at all. When you refuse to produce the data to support your cliams that's perfectly fine by you. But when somebody disagrees, THEY have to produce data ?