What is the mechanism that prevents microevolution to become macroevolution?

Speciation could occur both without any loss of alleles AND without mutations it seems to me, simply with a change in frequencies caused by a population split that sharply reduces the effect of some of them in the new population, especially a small population. This alone will bring up new traits and distinguish one population (or "breed" or sometimes even "species") from another. And I really doubt that mutation is necessary to lead to inability to interbreed; I'm not sure what the mechanisms for this would be except that some allelic situations or the possible death of some genes could make interbreeding difficult or impossible. This isn't being ignored so much as set aside in order to highlight the actual effect of the splitting and selecting processes in the general direction of reducing genetic diversity.But when we do focus on it, questions about it do come up. The splitting processes are easy to recognize: Thousands of already-present alleles -- including very possibly quite a few alleles, a dozen or so or more possibly, for a given gene -- shuffling around and pairing up in many reproductive events is easy to picture. How mutation enters into this is not easy to picture. How mutation is even NEEDED is a question considering all the allelic possibilities there are in some large populations. And this is separate from whether the mutations known to happen make any kind of contribution in the form of new traits that get passed on. There is no need for such mutations to occur to bring about great changes in two separated populations simply from the change in frequency of alleles, and possible complete elimination of some alleles -- no need, and no evidence that mutation actually makes a contribution to this process. You can breed dogs to enhance particular EXISTING traits, you know, simply by combining existing alleles for the traits you desire, and a big factor in this process is the elmination of competing alleles.There is no need to postulate the addition of anything new in the form of mutations in this process. MAYBE mutation is a part of it, but so far it sounds mostly hypthetical. It depends. I'm talking about a TREND, as I've said. I've grasped this just fine. I focus on the little group because it will express the greatest changes in the phenotype thanks to its depleted genetic diversity caused by the reduction in allelic possibilities. This is the trend I am trying to focus on here. All theory, all fantasy. Again, mutation is not needed to produce new phenotypes. Reduced genetic diversity is what brings this about, the removal of some alleles so that others come to expression. A lot of genetic information is not needed for speciation. Reduction of genetic information and genetic diversity will do it quite efficiently. That's the point.Now, of course you would like to have a lot of genetic information if the ToE makes sense. But no, speciation does not need a lot of genetic information. {EDIT: What this implies is that speciation and the ToE are at odds, exactly the opposite of what you claim, and the opposite of what must be the case if the ToE is true.} Yes, but I'm very unsure of the actual character of these "new alleles." Well, but it's been explained how it happens and it makes sense. The problem is that evolutionists assign a great role to mutation that is really not justified. It isn't needed, as I've said, and it hasn't been demonstrated. It is merely assumed. Certainly. Extinction is the perfect example. What is not generally acknowledged is that it is those "processes of evolution" that lead to "speciation" that make species ultimately vulnerable to extinction when a certain number of splits have occurred or a drastic split like a bottleneck occurs. The cheetah is a prime example. The cheetah does pretty well considering its drastically allelically depleted condition.The reason this is not recognized is that mutation is ASSUMED to take up the slack -- merely assumed, as far as I can see, without the kind of evidence needed to show that it could play that role, given the actual things mutation is and does, or certainly that it does.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

What I'm saying is that a bottleneck is simply an extreme version of a number of the selecting and population-splitting processes that cause new traits to appear in the phenotype. As I've been explaining, and so has MJFloresta, sometimes the process is subtle, not involving actual loss of alleles to a population but simply changing their frequencies so that some that predominated in the combined population before the split may no longer be expressed as much or at all, while others will be. Phenotypic change is the product of these changes. When the population split or selection process is drastic and reduces a new population to very small numbers then the changes may be dramatic, and what has happened then is that a LOT of alleles have been lost and the ones left are coming to expression and creating a new phenotype that characterizes the new population. There are degrees of this between the very subtle and the very dramatic. But a founding population IS like a bottleneck and it's the bottleneck or founder effect that is causing the speciation, not the other way around. That is, the bottleneck or founder effect eliminates a great many alleles so that now the alleles that are left define the new small population. This brings about a new phenotype, even a new species. Reduced genetic variability = phenotypic change or speciation. Yes, that's an example of a drastic bottleneck, but the speciation is brought about simply by the reduced allelic possibilities in the new population, allowing the few that remain to be expressed as new traits in the phenotype. Well, I suppose it's possible that the bottleneck simply might select out the very alleles that are already most expressed in the population and there would be little phenotypic change. I can't think of another way this might happen. Yes, nearly as much if there is no loss of alleles or the loss is minor. But any loss of alleles is the same thing as a reduction in genetic diversity. That is, there are that many fewer allelic possibilities for the population as a whole. Must have misread you here. It doesn't matter what the cause is, a bottleneck is an extreme reduction in population which involves an extreme loss of alleles from the original population, and this great reduction in alleles allows the fewer number of alleles in the bottlenecked population to be expressed in the phenotype. If these alleles include some that didn't get expressed in the original population then the new traits will comprise a dramatically new phenotype.But I don't see that it matters a lot whether the cause is random or not, although the targeted selection of particular alleles over others would certainly be a more dramatic case. But even in a random situation, if the overall number of alleles is severely reduced by the event, whether it's the geographic separation-plus-loss of inbreeding ability over time, or natural selection by which a very few adaptive traits are selected from a population in which the vast majority die, overall there will be this tendency to reduction in number of alleles which is the same as decrease in genetic/allelic variability, and this can bring new traits out in a population. Again, the more drastic the population reduction, the more dramatic the loss of genetic variability and the greater the phenotypic change -- on out to speciation. Since you are talking about a bottleneck all these thoughts are out of place. With a large number of alleles no longer available to the bottlenecked population there is simply a great loss of diversity right there. Even if there is a striking phenotypic change you may still not want to call it a new species. It depends, but it is certainly change in the direction of speciation.You think mutation could make this up, but mutation's role is being questioned here. It hasn't made it up for the cheetah yet. How long should it take? Yes, drift is the situation of no population split which we've been acknowledging may change the phenotype without reduction in diversity. It's the natural playing out of changing allelic frequencies in the population that brings this about in this case. Nothing new is added, only the frequencies change. That's all it takes to change a phenotype, the shuffling of allele frequencies. But there is definitely a loss of diversity IN the subpopulations and this is what we are talking about. If they can't interbreed then they can't recombine their alleles so the diversity they share between them is meaningless. Meanwhile, within the smaller new populations you have new allelic frequencies, and some alleles from the former combined population may be completely lost. In both these cases you will see over time a change in the phenotype, but if alleles are actually lost, then you'll see both a reduction in genetic variability and the expression of new traits or phenotypes. Reduction = Speciation, as a trend over time. Only mutation. Nothing else.==================LATE BREAKING EDIT:====================={EDIT: Just realized that probably that paper that Wounded linked to meant what you seem to mean, where they say: which in my Message 32 I answered:

quote:

---

Yes, of course. THAT'S WHAT SPECIATION DOES, IT SEVERELY REDUCES GENETIC DIVERSITY. That's what a bottleneck is, severely reduced genetic diversity

---

So there does seem to be this idea that speciation CAUSES bottlenecks. So the idea is that mutations occur that get selected, this being the evolutionist idea of how evolution happens, which of course means that speciation happens this way, and this causes a bottleneck during the phase that the selected mutations are forming a new population.Some thoughts:
This implies that these supposed mutations replace other perfectly viable alleles in the population, based on some posited advantage that causes them to be selected over the others, in some particular area of function.I'm going to have to ponder this some more, but maybe I finally figured out what is generally thought. Seems like it can't possibly work if you think about the whole supposed history of evolution.Also odd, it seems to me, that this notion seems to have so completely eclipsed the obvious normal way new phenotypes are created, by the changing of the frequencies of alleles already in the population. That is you just select what is already there, and has perhaps always already been there, not something new. You just pick the best version of it to see if you can breed a yet better version of it.But it's probably too early in the morning after another night of insomnia to try to think so hard.MAYBE IT WOULD HELP IF SOMEBODY DID GO TO THE TROUBLE TO TRANSLATE THAT ARTICLE FOR ME. I'D APPRECIATE THE EFFORT.Edited by Faith, : No reason given.Edited by Faith, : punctuation, grammarEdited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

You are right, and I suppose I could still try to turn it in that direction. I got discouraged somehow.

You are right that I did initially reject it before reading much of it, just bogged down after the first few sentences. But now I have the whole thing in Word and have really struggled with it and can say that it is absolutely definitely a lost cause. If such a paper really has useful information to offer, it should NEVER be presented to a nonscientist untranslated and undigested like that.

Maybe I can explain. This is becoming an extremely interesting problem now that I'm finally getting how evolutionists think about this stuff. Halted by the bottleneck. Hm.Now the article that Wounded King linked, and a few things RAZD said, suggest that speciation itself, or the very stepping stone of evolution itself, *creates* a bottleneck.So now we have that evolution both creates a bottleneck and is halted by a bottleneck. Interesting.No wonder mutation is treated as so necessary to explain everything. Well, now, have any of those mutations provided some allelic alternatives exactly in the places where the cheetah has been making do with just one for so long? -- that is, at many loci, not just one, not just a few, but many. The only mutations that could help the creature would be very functional beneficial ones at those particular loci. Could we please have some evidence of this?Me, I'd worry about that high mutation rate in such an allelically depleted creature on the verge of extinction. But that's because I tend to look at mutation with a bit of a jaundiced eye, as rarely friend and largely foe. Not according to Creo Theory it wouldn't, because we have the reverse model from the ToE. We postulate that all living things started with a large genetic potential in the genome that has gradually played out over the millennia, and that it was still very large on the ark {edit: And is still surprisingly large even now, except for some species going or gone extinct}. On this idea Adam and Eve alone had the genetic potential built into just the two of them for all humanity to descend from them -- and since Eve was taken from Adam I think we can assume their genomes were identical. By the time we get to Noah and his three sons there was still enough genetic potential to beget every human being who has lived since then and lives now --from just those three sons and their wives.But to answer your first question. According to Creo Theory, the allelic starvation of the cheetah caused by a bottleneck is an illustration of exactly the opposite of what you are saying and what evolutionists in general think. The cheetah IS the new species, brought about the way all new species are brought about, by the elimination or suppression of some alleles while others are expressed in the phenotype. In the case of the cheetah all the competing alleles are simply gone and its depleted condition even prevents it from being interbred with other cats so as to improve its health.In other words, in a maximal irony, it is the very process of speciation itself that brings evolution to a halt -- and provides that barrier that defines a Kind. Which I've been arguing for months now.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

I'm still hoping to get to your post here, but right now I seem to have forgotten again what this bacteria example is supposed to demonstrate and must ask that you explain it again.You get a whole population from a single bacterium with its one allele -- a whole population of that one kind of bactera with that one allele. And does this allele then mutate somewhere in that population, is that what this is all about? Does it mutate in a beneficial way? I'm probably punchy from being up all night, but I would appreciate getting this explained again. Thanks.

I think I got it and characterized it correctly although maybe my terminology is different enough to be confusing. Yes, this is all clear to me at least in a very general way, though I may not grasp all the technical aspects of it. I've assumed without stating it that a number of genes will be affected at once. All implicit or explicit in what I've been saying I believe, although perhaps I said it in some other posts than mine to you, I don't remember. The less gene flow the more divergence I would assume. The bolded sentence alerted me to look for the evidence that mutations are involved in this, and I haven't seen it. I don't know what "linkage disequilibrium" means, but the main thing is I don't see any reason at all from what you've described here how mutation is necessary to explain anything about this hybrid zone. The usual combining of alleles, different sets of them from the populations at both ends but affected by the different frequencies in both caused by the original split would do it I would think. I'd really appreciate it if instead of merely citing a technical paper a poster would give a brief abstract of it in nonscientific language. But at least you do go on to discuss an aspect of it: As I would expect. Less likelihood of gene flow between the two original populations plus more time for the differing allelic frequencies to manifest in the populations as a whole. I THINK I intuited what this means above although I don't know what "linkage disequilibrium" means. The differential selection pressures refers to the different allele frequencies on either side of the zone, which were brought about by the original split between them but became characteristic or more or less evenly spread in each population over time, and the new frequencies now produce a hybrid zone that reflects these new characteristics on either side of it rather than the original characteristics. All easily explained from the original given set of alleles without anything new added. Again, what I would expect and have been describing in various posts here. I don't really get this point about the selection pressures against the hybrids and how it figures in this, but I would expect the incompatibility-unto-speciation effect based on what I've been saying. I haven't assumed they would. And what demonstrates this? I haven't seen anything in the above that shows evidence of an increase in diversity, but most likely the opposite. That would imply an increase in alleles and that hasn't been shown. It is probably assumed, but it hasn't been shown. Oddly enough, given your certainty that these things are demonstrated in your post, I see only confirmation of what I've been saying. You haven't given any evidence of mutation for anything you've described, and as I've been postulating all along here, the genetic incompatibility at the ends of the chain of populations can most likely be explained by the decreasing "fit" between the genomes as they've differentiated over time based on their differing sets of alleles, maybe even merely differing frequencies of the same alleles. I see no reason to assume mutation in this process. So what I see here is what I've been describing: speciation or approach to speciation as the result of a reduction in genetic diversity / number of alleles.Edited by Faith, : No reason given.

OK, I guess something in what you said wasn't clear to me. Anyway, I'm going with the sexual recombination view of it as the most common way this happens. Mutation remains a big question mark, not that it doesn't happen, but that it very seldom does anything desirable from the point of view of the species. I know there are different kinds of mutations and I'm still open to the possibility that maybe some of it is beneficial, but given the facts that sexual recombination produces all the necessary changes to speciation without it, and that most of its effects are either null or deleterious, and that so far only about a dozen putatively beneficial examples have been given, it's still very much in doubt in my mind. I did not see that anything said about that example showed that mutation had to be involved. You said it was involved but haven't proved it. From what I read, reshuffling existing alleles can explain it just fine. This is what one would expect from the ways alleles get shuffled in the normal course of things. Gene flow between the two would keep supplying diversity, {edit: that is, resupplying it, recombining formerly lost alleles, but over time this tends to homogenization rather than divergence} but otherwise, without the gene flow, the separated populations would develop differing phenotypes based on their different allele frequencies, which might include the absence of some alleles as well. Since I think the {EDIT: following above }paragraph is where our views most sharply diverge I'm going to respond to pieces of it as I go: Yes, clear. OK OK. Perhaps I should adopt the term, since this is the very situation my argument has specifically focused on all along. That is, while the divergence between the populations MAY be simply a reflection of new allele frequencies without any actual loss of alleles, and speciation can occur even with this situation, or at least be approached by it (since a change in the frequencies will produce new phenotypes), the actual loss of alleles means a loss of genetic diversity; that is, there are fewer allelic possibilities in at least one population -- and possibly in both as they may both have lost alleles to the other in the exchange at the population split. Fewer alleles means reduced genetic diversity and it may also possibly mean a more rapid path to speciation. Exactly, as I've been arguing. And this is most likely to have been brought about by the migration of a small population, which is less likely to contain all the alleles in the original combined population. Well, many things may bring about this disequilibrium, as I've been arguing for months. Migration of a small portion of the population as I mention above may eliminate quite a few alleles from the new population; bottleneck certainly does it, and founder effect -- those are the most drastic routes to allele elimination = reduced genetic diversity = dramatic phenotypic divergence = speciation. Natural selection may sometimes exert just as drastic an effect by favoring one allelic set while all the others in the population die. In fact all the "evolutionary processes" that split populations can bring about this condition of allele loss. So does geographic separation all by itself in some cases though, as well as all the other processes I just listed. But OK so does this more complex scenario involving the hybrid zone. Yes. However, this raises an interesting side question about what degree of allelic overlap may continue to exist between two populations that have clearly speciated away from each other. Oh but I do not see why not. This has been asserted many times but only asserted. Mutation seems to be assumed in this scenario but it has not been proved to have a part in it at all. Since mutations occur frequently I can't deny that they've occurred, but their role in this scenario of divergence has not been shown.I think you are confusing diversity of phenotypes with diversity of genotypes. {EDIT: Should not have used the term "genotypes." This confuses the issue. I mean diversity of allelic possibilities or many allelic possibilites.} Great divergence in the phenotype may be brought about by a change in allele frequencies, but an even greater one by a complete loss of alleles formerly present in the formerly combined population. It is the reduction of alleles that leads to diversity of phenotypes. Less genetic diversity = greater phenotypic divergence from the original population. Reduced number of alleles = reduced genetic diversity = still the main route to speciation. Gene flow would never account for divergence at all, it tends to homogenize rather than diversify. Yes, I believe you have confused divergence of phenotypes with genetic diversity. It is the loss of genetic diversity that produces the divergence of phenotypes in the ordinary course of sexual recombination.===
Sorry if you did indeed abstract the technical paper. I thought you'd said you weren't going to but simply cite it for others, and then went on to mention one aspect of it. My mistake. No, I'm not asking for the detailed technical information, just a clear discussion of the content of the paper. Apparently this has been covered so no problem. But this is precisely the situation I've been addressing from the getgo in my own arguments, this different set of alleles in each source population. This is indeed what makes them distinct subspecies, and, as I've been arguing, this is most likely brought about by the loss of alleles between the two of them. This means decreased genetic diversity. This is what brings about new phenotypes and, at greater degrees of divergence, even new species. Mutation is not needed in this scenario at all. I'm not arguing that you haven't provided evidence. You've provided a great deal of evidence. But you haven't grasped that the evidence you've provided does not support the idea that mutation is necessary at any point in all the situations you've described. It actually supports what I've been arguing for, that speciation is the result of reduced genetic diversity, which is the opposite of what is needed for evolution. Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

You got a lot of it, Ben. Thanks. But I'm saying more than this. I'm saying that the very processes of microevolution lead to what is called speciation, but that speciation is bought at the price of reduced genetic diversity through the reduction of alleles in the population, so that you end up with the scenario that directly contradicts evolution and provides the defining limits of a Kind. The actual processes that are happening toward speciation, or phenotypic divergence, are brought about by, or characterized by, a loss of genetic diversity: Speciation = reduced genetic diversity. No way you are going to get evolution out of that formula, which reflects the actual reality. The degree and quality of mutation needed to overcome this inexorable trend is incalculable.Yes, this is very on-topic. This has been my argument from my first thread at EvC, Natural Limitation to Evolutionary Processes or however it was titled.{Edit: I have to keep repeating the formula in various forms:Phenotypic Divergence (first step to speciation) is the result of Decreased Genetic Diversity.Speciation and Evolution are at odds with each other. The more speciation the less possibility of evolution.Again: Barring of course a prodigiously huge amount of beneficial mutations, and this would take some thinking about anyway.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

OK, that's really all I needed to have confirmed, thanks. I just tend to forget. No need for anything more technical. So these mutations are apparently either neutral or beneficial?

What I'm asking is whether it is a mistake, a disease process, an attack on the integrity of the organism, or really can be relied upon to produce something useful. I'm not sure what information would show me this one way or another but so far I'm still mostly in the dark about it. I'm very sure getting more technical isn't going to do it.Even if most of the results are neutral it seems this might be a fair way to characterize it. And since the actual number of examples given so far of what are termed beneficial mutations is so small I'm just not buying that mutation figures much in normal genetic transmission. Yes but.One interesting thing about bacteria -- I suspected this or at least wondered so I looked it up and sure enough, bacteria don't have any junk DNA. I found an article where they were theorizing about why this might be. I think this is a major difference between bacteria and other creatures myself but the full implications of it await a bolt of illumination. It is hard to explain why I just don't trust this bacteria bit. Chipmunks do not need mutations. None of us need mutations. All the diversity of traits / phenotypes imaginable is possible with merely the given allotment of alleles. In this light mutations are just some sort of intrusion. Mm but exactly how certain are you that no ancestory had it, and that it's not just an extremely rare one that happened to pop up?But if it is a mutation, then every time one is identified it needs to be identified according to what it does to the organism. Is it a mistake, is it a disease process, is it really just basically destructive etc.? But ruling out the possibility of rare alleles coming to expression can't be a sure thing.And again, if they are mutations, are these really viable alleles mutation is bringing about? Do they look like normal alleles? Do they code the same way? And what effects do they cause? OK, so you know you have a mutation. Then the questions about what the change actually does are the main thing. And what does that work out to in a human time frame? How many viable new alleles per unit of time? No I'm just as usual pondering their sounding like something deleterious although they sometimes get called beneficial and I'm not convinced. This plus the fact that I'm convinced that normal allelic shuffling and transmission is all that's needed to account for all the processes of phenotype divergence, which makes mutations inexplicable.

Yes, that would be a good test. Any way to conduct it?Forget anything "before Creation." That wouldn't falsify what I'm predicting but simply bring in some whole other frame of reference.

But divergence we expect, remember. It's the genetic diversity we expect to decrease while the phenotype changes. I don't think this is what we are claiming. We are talking about alleles being lost, which wouldn't affect the size of the genome, which contains the genes the alleles take turns occupying as it were.*.However, if our notion is true that a bigger original genome is implied to explain how all life could descend from an original pair, then this wouldn't happen with each "speciation" event but over greater swaths of time along the lines jar is suggesting -- something we would see over millennia, not generations. I don't know how this would work genetically of course but genes themselves would have to die, not just lose allelic contenders. *. *. {Edit: In other words, ALL the alleles for a particular gene would have to be lost to the organism, and lost for many genes, which would mean the loss of many entire genes, before the genome would appear appreciably smaller. **.--Here is where I look inquiringly toward the "junk DNA"}{Edit: **. This wouldn't happen in the normal course of sexual recombination, however, even with any amount of severe isolation or selection, even the most drastic bottlenecks, because there would always be at least one allele for all the loci and the cheetah does just fine with that condition, considering. What brings about extinction is probably mutations that cause diseases and that themselves kill alleles. Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

But novelty can arise in a new split-off population just by the fact that previously suppressed alleles may now be expressed. Gene flow if anything would keep them suppressed. In the new populations gene flow will then smooth out the new phenotype over time as it were, until the whole population will have developed its new characteristics around the novel newly expressed alleles, and then the whole group can be distinguished from the other, but gene flow BETWEEN the populations would only interfere with this diverging process.Edited by Faith, : No reason given.

Quetzal doesn't yet completely grasp what we are arguing. Those supposed answers don't answer it, and in fact I've addressed that post in my two posts above.Edited by Faith, : No reason given.