What is the mechanism that prevents microevolution to become macroevolution?

I still don't understand. We know for a fact that mutations do occur. It seems that you agree with that. But somehow you believe that that might not be enough to increase the number of alleles in a population. How come?

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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.

You can know there is a decrease in something without being able to quantify it. That's an everyday experience. And I showed the logic by which a decrease should be expected in genetic diversity. Demanding numbers is just a distraction from that fact.Where did I say I "know the population of the human race at very set times?"Scientists SHOULD know the numbers, but maybe because they aren't looking in the right place for the right phenomena, they apparently don't.

I am not asking for data because I want it, but because others have claimed it exists. RAZD, Crash. So if you claim it exists, bring it forth. It obviously doesn't exist, just the usual paltry few examples of iffily beneficial mutations, no count of alleles for a number of genes in a population before and after speciation, nothing like that so far. That is asking a lot of a supposedly random process, but then show that much. Bring out the numbers that prove that. That's true, and that should be taken into account along with the selecting and other reducing pressures, what you start with and how much change occurred.=============== I have no idea where you get stuff like this. 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. 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. Edited by Faith, : No reason given.

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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

Except nobody will because this is just a crazy creo idea, right?But the only way this could be determined for sure is if someone would do the necessary studies, counting alleles before and after a population of a new phenotype is developed. I think ring species would be the perfect place to start because there you have a number of populations of which each has split off from the previous population, so you ought to be able to tell which genes have lost or gained alleles at different points along the way. The more complete the count the better, because it's very possible that a very rare allele in population 1 did not make it to pop. 2, and this might not be caught on a random sampling.Really the best situation would be a laboratory setup, in which you breed a population of a few hundred wild mice or wild somethings, all colors and fur types or what-have-you all mixed in together, do a complete DNA analysis on every single one of them, targeting particular genes I suppose, maybe tag them if you really want to keep track of where all the alleles go, and then after they've all mixed together for a while and increased the population (beyond the lab's ability to handle it?) and I would guess perhaps established a group phenotype? How many generations would that take? I guess you could be in this lab for a while doing this, and being overrun with mice. But anyway, then you create an artificial ring species. You randomly take a couple dozen out to start their own population, checking DNA as you go and tallying alleles per gene. Maybe you could make a number of new populations at once, start many ring species, the more the better for the sake of really seeing how alleles sort out from population to population. As long as you keep impeccable and obsessionally thorough records it should be interesting.Then after pop. 2 (or all 3 or 4 pop. 2's: 2a, 2b, 2c etc.) has developed a characteristic phenotype (which I assume it will since that's what happens in wild ring species), then take a couple dozen out of that one and do the same thing, and so on until you have at least four populations that have been bred only from each previous one. Go for five or six. In life you'd probably have some gene flow, and a hybrid zone of the sort described in the article about the salamanders of the Sierra, that Quetzal linked back there somewhere, but to make the point about alleles being lost in the process of random isolation, this experiment I'm suggesting ought to make it quite clear if it does or doesn't occur.If you want to set me up with the lab and the mice I'll do it myself. I can't read the DNA myself though, I'll have to hire one of you all to do that. Or you could train me. I'd really like to know how these numbers work out. Maybe salamanders would be better to work with. Or chipmunks. Need a very big lab for that I suppose.

Oh, so you don't believe Adam and Eve were the total population of the human race at one time?You have suggested that there has been an ongoing decrease in human genetic diversity. I'm trying to find out how you think this has unfolded.

No, I'm simply not a mindreader, had no idea what you were thinking of. OK, yes I know it was a total of 2 about 6000 years ago and a total of 8 about 4500 years ago if that's what you mean. What was your point again? I think all human and animal genetic diversity was drastically reduced at the Flood of course, and that it is still gradually decreasing across all species. This is particularly apparent in some like the cheetah, and highly inbred domestic animals, and others that have become so genetically depleted they are on the verge of extinction, many already extinct. Actual numbers I have no idea, it's a trend I'm talking about.I have the impression that human beings have maintained genetic diversity pretty well, and our being less isolated in our racial groups than we used to be probably helps too, as racial intermarriage is a good thing for increasing genetic diversity, so we may have a ways to go before genetic diseases do us in completely.And if God keeps blessing us with new medical treatments we may prolong it quite a bit farther. Except I have no reason to think God is going to continue to bless us with much of anything for much longer since as a species, the one made in His image even, we have pretty much turned our back on him.I hope this answers your question.

You would probably be better off using something like fruit flies which have a shorter generation time and require much less effort and expense to maintain in high numbers. Then again it is much easier to get a non-destructive, at least relatively, tissue sample from a mouse than it might be from a fly.Your idea isn't bad in basic theory, although the idea that you can simply create an artifical ring species is a bit tenuous. As you yourself note however the numbers involved would be very high. Consequently the amount of effort needed to sequence DNA from all of your poulation would also be very high and the amount of money required to do so would be concomitantly large.I have found a study which has some similarities to your idea, but it is based on phenotypic characterisation of a particular trait rather than gene/genomic sequencing, it also only focuses on the persistence of deleterious alleles and does not involve bottlenecking the populations(Yampolsky et al., 2005). This study shows that in the populations under observation deleterious eye phenotype alleles usually persist for between 50 and 100 generations.TTFN,WK

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 ?

Sigh. I think you need a sense of humor Paul.It's not an "opinion" it's a logical conclusion from the processes described. Understand the processes and you arrive at the conclusion. It's straightforward. There's no other direction for the processes to go than decrease in genetic diversity -- meaning all of the processes except mutation, and since mutation AS DESCRIBED BY YOU ALL HERE is this pathetic bunch of wild random changes, most of which are undesirable or unknown, which most likely means ultimately undesirable, and very very pathetically few that can be claimed to be "positive," and a couple of these are in bacteria which doesn't do the human race any good, I'd say yes, it is also a LOGICAL CONCLUSION that mutation cannot possibly alter this inevitable trend to decreased genetic diversity. It's not an opinion, it's an educated guess, and a prediction of the outcome of any lab studies of the sort I suggested.Edited by Faith, : No reason given.

Your "logical conclusion" is, in this case, not shared by others. It is an opinion. As you have been told countless times, your so-called "logical conclusions" do not equate to facts. Nor are they logical, most especially when one considers their foundations:-- You reject evidence of benefitial mutation whilst providing no counter-evidence.- You have posited some spiritual mechanism which can limit "degredation", but which you have failed to define.- You have also failed to define the exact nature of of a "kind", from which said "degredation" supposedly takes place.These, Faith, are the foundations of your "logical conclusions".

Yes, I figured you'd need to be able to get a good DNA sample, no good if you kill the creature in the process.I don't know about doing it just from phenotype with mice. Mice are pretty much the same everywhere. How much built-in diversity can be counted on with mice? Chipmunks apparently develop recognizable differences from one population to another in a ring species. Maybe mice just don't do ring species for some reason and if they did we'd see variations there too. Anyway, I did think about those practical questions. Can a lab be set up to deal with 10,000 mice if it should come to that? Yes, very expensive.I looked at the link but I'll have to read it tomorrow.Anyway, thanks for saying the basic theory wasn't bad. For a dumb creo who gets everything wrong and has no respect for science that's a nice compliment.

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It's not an "opinion" it's a logical conclusion from the processes described. Understand the processes and you arrive at the conclusion.

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But your argument was that mutation can't keep up IF YOU IGNORE MUTATION. That is not a logical argument, it's just begging the question.As for the rest of your rant, without taking into account the rate at which alleles are lost - and by ignoring the fact that selection biases the loss in favour of retaining beneficial alleles you have no case. You can't claim that the loss is greater than the gain wihtout examining both sides - which you keep on refusing to even consider.

I haven't participated very much in this thread, but since it is ending soon I just want to note that I don't think the topic of this thread has ever been addressed. There's been a lot of discussion about mutation, but as far as a mechanism preventing micro-evolution from becoming macroevolution, nothing.If this topic comes up again I think the creationists need to better understand what they're claiming. An analogy would be micro-walking versus macro-walking. What keeps a micro-walk from becoming a macro-walk. Well, if you live in the continental United States, nothing prevents this. If you can walk to the store then you can walk across the country, it just takes longer. But if you live on a small desert island then the island's coastline is the limit of walking, and it makes macro-walking impossible.Just as an island's coast prevents macro-walking, creationists have to identify some boundary or mechanism that prevents macroevolution.--Percy