Evolution Requires Reduction in Genetic Diversity

I have not ignored them I've explained that they don't stop the march to genetic depletion, all they do is contribute some of the material that selection depletes. I'm looking for a model to demonstrate this.

I regret my heated words and am taking them back. Forgive me.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

Deleterious can mean doing damage that doesn't show up in a changed function except after many mutations have accumulated, and I'd guess such sleeper mutations as it were constitute the majority of the mutations out there. Just a guess. If that's diversity you can have it.Prediction from this guess is that we'll be seeing lots more genetic diseases in the near future.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

That's your prediction. Mine is what I said. We wait and see.

For some reason you are particularly interested in getting an answer from me to this post? I'm not sure why or what answer you are looking for.I can assure you that at no time on this thread or any time since I've been working on this argument have I imposed my beliefs on it or tried to make it fit my beliefs. Not the Creation, not the Fall, none of that. But of course I have many times tried to take the argument back to those points looking for explanations for how it would have worked. Of course I pursue the argument so determinedly because it DOES fit my beliefs, of course, but I didn't start with the belief.I recognized that selection and isolation, considered to be processes of evolution, inevitably reduce genetic diversity and that there has to be an end point to that process beyond which evolution can't continue. It's something I recognized and I've been working it through ever since. The end point may not be reached in reality very often but it's always theoretically there as the point at which all the processes are aiming.I couldn't have been trying to find a definition of the Kind because we've all been looking for a completely different definition, but it did seem to me that the theoretical end point I was seeing did provide a definition, different than the definition we've all been looking for, a functional definition. Where the processes of change or evolution stop on any particular path because of genetic depletion, that functionally defines the boundary of the Kind on that particular path.I do think it's intuitively obvious that mutations are just going to be fodder for the selective processes and can't possibly prevent the eventual inevitable if theoretical arrival at the end point, and I think it ought to be recognized just from the descriptions I've given, but perhaps I'll eventually find a model that can demonstrate it. The picture that comes to mind at the moment is of a person dying of a heart attack that the doctors are trying to revive with those electric stimulators, and the heart revives for a few beats but then dies and then they revive it again for a few beats but then it dies again. That is NOT a good model, it's just what comes to mind at the moment.If you want me to respond to Ayn Rand's comments about the Fall all I can say is I don't like Ayn Rand and think her comments about religion are ridiculous.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.Edited by Faith, : No reason given.

Second answer: I missed the context in the other answer, which is the prediction of more genetic disease.I could have predicted that just because I believe mutations are predominantly deleterious, without believing in the Fall.But yes I do believe in the Fall and deleterious mutations do fit into it, and so does my argument.

I do wish that I could have pursued this argument further because there are issues I still need to work out.One of them is what HBD raised a while back about the number of alleles per gene in relation to any theory about the original genome I've been able to come up with. I may have to figure mutations in to that extent at least. Maybe take this discussion to the old thread Introduction to Genetics.Another is how large populations of animals that DO have high genetic diversity nevertheless appear so homogeneous phenotypically. I think of the wild herds of Wildebeests and buffalo and I figure it must have been true of the wild herds of cattle from which all our domestic breeds descended. This is another question about normal genetics.That is, I think I understand pretty well how new varieties or phenotypes develop from a small isolated population, because it's the reduction of genetic diversity that brings it about. BUT even so the new phenotype wouldn't appear for a number of generations. The first individuals to form the new population would look just like the original population. But over a few generations of inbreeding within the new group the new frequencies of alleles would start producing new combinations and bringing out new traits. So I'm picturing a phase where the former homogeneity of the orignal population is giving way to a more motley mix of different traits in different individuals because of the new mix of alleles. But eventually the population would develop a phenotype to which all the individuals conform. THAT's interesting it seems to me. It must occur through the mixng and remixing of the new gene frequencies through a number of generations until they're all thoroughly mixed together. I've figured that could take a few hundred years in some cases. But I'd still like to be able to picture it at the level of the genome, what's happening there.Whatever is happening there is also what brought about the original homogeneity of the phenotype of the original large population with its greater genetic diversity. In such a population new traits should be showing up in every generation in every individual anyway, because of new combinations occurring, but not to enough of an extent to stand out in the crowd. It's only when the selection processes begin to favor a trait and multiply it that a whole new population begins to develop with a whole new look.Somebody back in the thread spoke as if I ASSUME that I can just extrapolate what happens in breeding to wild populations, but really it seems to me that it's pretty obvious that the same processes have to occur. The only thing that would be different according to standard theory is that mutations would occur much more frequently in a larger population, increasing its genetic diversity. But the same arising of new traits would happen pheotypically if the new traits were in fact brought about instead by "ancestral" or built-in alleles, which is my usual assumption. You'd get an increase in genetic diversity IF mutations do produce viable alleles for new traits, yes, but it seems to me all that would do is put off the inevitable for a longer period. The inevitable is still the inevitable reduction that has to occur through the various selection processes IF new phenotypes or varieties or breeds are to develop. Mutations would vary alleles for particular genes, therefore for particular traits as defined by those genes, and it's hard to see how that would make any appreciable difference to the development of new varieties with its inevitable necessity of reducing genetic diversity. Again, it could only put off the inevitable, delay it at best.If you look up Cattle Breeds at Wikipedia you'll find out that there are some 800 domesticated breeds. There are pictures. They vary in their coloring and markings, size of horns and body structure and also their meat and milk quality.Simply removing and isolating relatively small populations from the original wild herd of cattle would have brought about changes through the new gene frequencies as the new populations inbred over some number of generations, but of course most of the breeds were also developed by human selection of desired traits as well, including hybridization by mixing with other breeds.Each of these 800 populations would naturally have less genetic diversity than the original wild population, which alone is all it takes for a new peculiar phenotype to develop, same as with all domesticated animals. You don't need mutations for that. Some here have agreed that this is how it happens in domestic breeding anyway, that it's simply the small numbers inbreeding, with their severely reduced genetic diveristy compared to the population at large, that forms the separate breeds. Mutations are just not needed. So I don't see why they would be needed to create the various cattle breeds either. I guess they may occur from time to time as usual but the natural mix of genes culled from the original population is quite sufficient to bring about all the breeds.Again I'd mention that a breed in order to "breed true" generation after generation must have much homozygosity for its peculiar traits, meaning it must have ONLY the alleles needed to form those traits, whether singly or in whatever combinations produce them, which is a very great reduction in genetic diversity, all other alleles for those traits having been left back in the mother populations. To what extent this occurs in cattle breeds I don't know. Breeding true may involve human intervention to prevent undesired cross breeding more than it involves a genetic condition like homozygosity but it would be interesting to know. I think I read that the Hereford breed, wish I kept better track of my sources, only fully developed its characteristic look reliably from generation to generation within the last century, which could mean it finally arrived at homozygosity for its characteristics, all competing alleles finally having been eliminated from the breed.There are still wild herds, and variation of course doesn't happen as frequently among them because they manage to keep their large populations pretty intact, but as soon as there is a migration of some portion of them they will also start to vary and why shouldn't they vary according to the same principles as domestic breeds do? This also does not require mutation. It just requires a change in gene frequencies which is the natural result of isolating a portion of the original population. There may also BE mutations but they are not needed for the changes to develop.So according to the Wikipedia article on the Wildebeest/gnu there are two main varieties or "species" of this animal that are geographically isolated from one another, and both exist in large populations and apparently do quite well. One is the black type and the other is the blue type. They think they diverged from each other some ten thousand years ago but if you think about how long it would take to work the new gene frequencies through a herd that started out as maybe a few hundred individuals that migrated away from the mother population which was maybe as numerous as hundreds of thousands or even a million why should it take more than a few hundred years?For everyone who keeps wanting "evidence" why isn't the logic of this argument sufficient to make the point? At least as an alternate theory, an alternate model? The only way I can think of to prove any of this or provide evidence is by DNA sampling. If the blue Wildebeest migrated from the black in sppreciably smaller numbers (and I don't know) then it should show fewer alleles for its pecular traits even to homozygosity for those traits as compared to the black type.Same with the domestic breeds of cattle. If there's any way to know anything about the original populations from which they developed you could look for the DNA evidence there too.Could do the same for all those ring species out there. As well as domestic breeds of dogs.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

Well, would you agree that if the faucet and drain are both open you aren't getting evolution? That is, you aren't getting the development of new varieties/species/breeds?If you are getting more increase in diversity than you are selection events you also aren't getting evolution, the development of new varieties/species/breeds. {ABE: As a matter of fact you can't have both faucet and drain operating at the same time. The "drain" is supposed to stand for the selection/isolation processes but those bring about new phenotypes FROM the genetic pool. Must be more like add THEN subtract, add THEN subtract in reality} What you are getting is perhaps new traits appearing here and there in individuals within the population. But for evolution to occur, that is the development of a new population with new characteristics, a new "species," you MUST have reproductive isolation/selection.Doesn't that seem true to you?This analogy really doesn't work though because this isn't a simple addition/subtraction issue and I wish I had a model for what it really is. If mutation is involved it could maybe be described as something like two steps forward, one step back. Add some diversity, knock it back with selection, add some more diversity, knock it back again.You HAVE to knock it back, that is, you HAVE to reduce the genetic diversity to get a new phenotype, breed, variety, species, in the wild as well as in domestic breeding, though the most accessible example is what happens in domestic breeding. If mutation really is involved it could only be a start-stop sort of thing along the lines I'm describing here, the continual adding of mutations merely delaying the inevitable.If it's built-in alleles providing the diversity for selection to work on rather than mutations then the process is more direct: you've got your gene pool whole and complete as is and selection and isolation then shape that gene pool through new gene frequencies.Mutations would keep changing the gene pool which sets back the selection effects, but it can't keep them from occurring IF you're going to get new "species." If all you get is balance or stasis, water in water out, again you aren't getting the production of new species, you aren't getting evolution.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

Not if evolution is the production of new species/varieties/breeds. All you get from the addition of mutations is more traits that COULD be the basis of a new species, but as long as they aren't being selected, no, you aren't getting evolution. You are getting lots of new traits here and there within the existing population. That is not evolution. No, it isn't a simple addition-subtraction thing. If alleles are flowing in you get stasis. If alleles are flowing OUT you are getting new phenotypes or varieties or breeds or species. Really they are two separate processes. It is the BASIS for phenotypic change, because the gene pool IS the basis for phenotypic change, but you aren't GETTING phenotypic change until you get reproductive isolation and selection. But that isn't evolution if evolution is the production of new species, which is brought about by the selection and isolation of a portion of the gene pool. All mutation does is add to the gene pool and that is not evolution, that's as you say the BASIS for phenotypic change but if selection does not act on it you do not have phenotypic change and do not have evolution.

Then you aren't really thinking about the reality of the situation which is not simple water in water out. "Water in" builds up the gene pool. That is NOT evolution if by evolution is meant the production of species. You DO agree that evolution IS the production of new species, don't you? Or is that now changed as well. The production of new species which is the "water out" part is brought about ONLY by the selection and isolating processes. You can have a ton of genetic diversity in the gene pool and the population not be evolving. If it is going to evolve into new species selection and isolation have to shape the gene pool. Anything can be the fodder for evolution. But if it's just a mutation for a trait in an individual that is not being selected you are not getting evolution. Mutations add diversity but only in separate individuals within the population but it just sits there unless selection is acting on it and if it acts on it THEN you are getting evolution and not before. "Water in" is NOT evolution. This is a ridiculous question it seems to me, that has nothing to do with anything I've said, so I assume you still don't have a clue what I'm talking about.Humans and domestic animals are different from wild species in that respect though. We do have an enormous range of recognizable diversity in PHENOTYPE that doesn't occur in wild animals. Grizzly bears all look like grizzly bears, chickadees all look like chickadees, starlings like starlings, lions like lions, Siberian tigers like Siberian tigers, blue wildebeests like blue wildebeests, a particular species of greenish warblers all look like each other and so on. There is variation in individuals in those populations too, but it isn't as dramatic as it is in humans and domestic breeds. Perhaps because our gene pool could never get that thoroughly mixed together as it does in wild animals. Thank you. I am aware of all that. No it isn't. Yes, but in the wild it would get blended in through the next generations which would form whatever phenotype or breed is going to form. Wild populations are not selected as breeds are but they are selected in the sense that they are nothing more than the mixing of an isolated gene pool with its own gene frequencies and that's the same thing as happens in breeding only the selecting forces are more random in the wild. Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

I know that, but if they are being selected and mutation is continuing to add to the gene pool you aren't getting a delineated recognizable species such as we see IN REALITY both in the wild and in breeding. This is all just some abstract idea that has nothing to do with what really happens. I don't know what you would get in this scenario but it's something blurry and constantly changing, NOT an identifiable new species which is what happens IN REALITY. See above. This is all theory gone bonkers, it has nothing to do with reality. Is evolution about forming new SPECIES or about the myriad of different traits that show up in all populations? New traits show up in individuals in my scenario too, WITHOUT mutations. But to GET that new species the traits have to be SELECTED AND ISOLATED. That's my point. The traits that constantly crop up in individuals in any fairly genetically diverse population, whether by mutation or by what I think it is, simply new combinations of existing alleles, do not constitute a new SPECIES unless selected, isolated and worked through the entire new gene pool. And THAT happens only when all the alleles for OTHER traits are suppressed, reduced, or eliminated = REDUCED GENETIC DIVERSITY REQUIRED TO FORM A NEW SPECIES. So? Should happen a lot in my scenario that you get new "species" from new mixes of old alleles. If you want to insist on mutations then realize that mutations are only going to keep delaying the formation of an identifiable new species by interfering with the gene pool from which the species is formed. But that isn't what happens in reality. So? I would assume there were lots of variations in the ancient world too, which on my system would be formed from new traits built from new combinations of alleles that are brought to expression by selection and isolation just as they are in living species today, not requiring mutations. Again if mutations are involved you're only going to get something blurry or delay in the formation of a new species. What you are calling new "species" is really just varieties or breeds of existing species, presumably having reached a point where they no longer interbreed with their mother populations, probably due to severe genetic depletion in some cases. And breeders could very well create a new species by that artificial definition if they keep at a particular breeding line without introducing new genes from time to time. With respect to the creation of new species it is stasis, it is not evolution. With mutations you are getting traits showing up in individuals here and there in a population that is not changing overall. That's stasis.If the only way to get a ceramic pot out of a hunk of clay is to pare away all the stuff that doesn't look like the ceramic pot, you aren't going to get the ceramic pot if you carve a little then add a little clay somewhere else and so on. Carve and add carve and add, no, that is not how it works in reality. What you guys seem not to appreciate is that the existing alleles and genes in a genetically diverse population are more than sufficient to form many many subspecies through selection and isolation of portions of the gene pool. New gene frequencies are all it takes, new combinations of old alleles. All the breeds of dogs came about from nothing more than this, also the cattle breeds, the cats, etc. etc. The alleles in the original wild populations are merely potential or latent, the traits they govern hidden from view as it were but when selected in new combinations they produce an amazing array of new traits and phenotypes. You do not NEED mutations to get all the variety in living things we see. Which is a different argument from whether mutations occur and contribute. In my system mutations are simply not needed, and can interfere. By which you mean what? That some individuals die off? Selection isn't occurring in any sense that produces a new species if there isn't reproductive isolation of what is being selected. Selection means particular traits are favored and multiply down the generations for that reason. That's the ONLY way you are going to get new traits in new combinations in an entire subpopulation. i.e. a new "species." NOT UNLESS THERE IS SELECTION. Genetic drift is a form of selection so that new subpopulations can form within larger existing populations, that's one way but it's slow. But the entire population isn't going to evolve because a motley collection of new traits isn't evolution. Some of them have to be selected in order to get evolution. I'm glad this is coming out now because it is SUCH a mistake. The same alleles and genes in NEW COMBINATIONS is all you need to form myriads of new varieties from a large genetically diverse population. The new combinations are brought about by the change in gene frequencies brought about by the reproductive isolation of a reduced number of individuals, making for a new gene pool of interbreeding individuals, and that's how new breeds, varieties, species come about. The new combinations are powerful sources of new traits. You do not need mutations. The creation of novel traits occurs from new gene frequencies, new combinations of existing alleles. You must be using the term "selection" in some other sense than I am. Selection is something that happens at the population level as I am using it. If perhaps you are talking about how sexual recombination works I guess that could be called selection with respect to individual traits, but I'm trying to keep the population level in mind which is where new species are formed. Sounds plausible in the abstract but in reality it's not what happens, it does not describe what really occurs.

According to my model on the other hand, I would say that the odds favor its having been latent in the gene pool and then brought to expression in a combination that's rare for that gene pool through mere sexual recombination. There are many ways a trait could be latent, starting with its allele(s) being rare in that particular collection of gene frequencies, but also including its not being expressed except as the product of particular alleles for a number of different genes in combination, prehaps also involving formerly unexpressed recessive alleles, or even dominant alleles that don't show up as visible traits except in particular combinations. Yes I understand that the argument I'm facing here involves the claim that breeding methods don't model evolution in the wild, but it IS my argument that the principles are the same no matter who or what is doing the selecting.Since it has been acknowledged by at least a few here that developing new breeds does involve reducing genetic diversity through mere selection of particular traits, and it's not an unreasonable idea that selection processes in the wild would operate in the same way, then the same kinds of processes would have to tend to the same conclusion, and they do, as exampled I believe in speciation events. Except of course in the wild the selection processes can be quite random such as migration and geographical isolation of a new gene pool which is not usually as small as those used in breeding, rather than caused by anything as actively selective as Natural Selection, though that may operate as well in some situations.Seems to me we have Darwin himself for an authority on the similarity with domestic selection as he drew his inspiration for natural selection from his own experiences with breeding pigeons, and extrapolated his method to the random influences found in nature. He was able to produce quite an array of spectacular pigeon variations simply by selecting individuals to mate for chosen traits, and made the very reasonable observation that nature must do something similar in order to get the many variations we see there; such as the differences between mainland turtles and the turtles on the Galapagos, as well as all those different kinds of finches. He was right of course, he just went too far with it.You all assume (without proof) that the traits chosen for breeding are created by mutation and there really isn't any way I can prove you wrong, but I don't see how you could claim that when the same trait is selected generation after generation with the effect that the chosen trait becomes strikingly large and elaborate, that mutations for each of those expansions and elaborations were the cause in each generation. Not if mutation is truly random you can't. The more reasonable explanation is that there is something in the genetic design itself that is capable of such elaborations. IF you are really observing a mutation and not confusing it with a normally occurring latent allele. But what KIND of diversity is NOT known in all cases. What is best known is the mutations that cause genetic diseases. Often deleterious ones. Yes and no. You are all more or less willing to accept ANY kind of change as valid in supporting your position, including deleterious changes. That isn't impressive to someone who thinks evolution has to produce changes that can be useful to the organism, no matter how cleverly you rationalize the possibility of a disease process sort of becoming useful in various contexts. Which as far as what is actually known is concerned is a very rare occurrence and the only one I can think of at the moment is the fact that sickle cell anemia protects against malaria. Not a hopeful situation for evolution it seems to me but then who am I to have an opinion? You aren't listing your evidence here but as I've encountered it most of the actual evidence that IS evidence is just as good evidence for creation as it is for evolution, often better, but besides that your evidence often amounts to wild interpretations, as of the fossil record, which creationists rightly laugh at. Or finding that since the octopus has an eye most similar to a human eye that proves that the human eye evolved even though there is no known genetic path, or even theoretical genetic path, that could have brought that about. And that sort of nonsense is treated as "evidence." Chortle. Not an assumption, this is really and truly what I recognized had to be true as I was following out arguments on this subject. Certainly no assumption. It was a very exciting discovery as a matter of fact. But of course proving it is an uphill battle, especially with all the evolutionists trying to throw me over the cliff. Good thing I bounce well.Edited by Faith, : No reason given.

Obviously, but Percy's "water in water out" model seems to be implying not only that they can be but are. My argument is first of all that mutation has nothing to do with increasing diversity since the only diversity it really increases is destructive, but that even IF it increases beneficial diversity then it can't be always coming along to undo the processes of selection and isolation or you'll never get new varieties. But the fact of the matter is that we DO get new varieties, both in breeding and in the wild, in the wild most of it brought about by random factors that isolate portions of a larger gene pool, a form of "selection" I'd say but random, not the intentional selection we see in breeding. The effect is nevertheless very similar: you get a new breed or variety or species or phenotype merely by the mixing of a new set of gene frequencies. That's all it takes to get new breeds, that's all it takes to get all the different breeds or varieties or "species" in a ring species, for instance, simple reproductive isolation of a new set of genes out of the larger gene pool, in the case of ring species most probably due to some members of the former population having migrated to a new location and by inbreeding bringing out traits that differ from their former population. By "survival dominance" you mean natural selection? I think speciation can be brought about simply by a series of migrations of some numbers of individuals from former populations, each migration producing a new variety with new traits by comparison with the previous population, from a reduced number of genetic possibilities because of the reduced numbers. If this kind of selection and isolation occurs over many migrations you can eventually get speciation from the highly reduced genetic diversity of the latest new population which can even lead to inability to interbreed with former populations. It can't "evolve" new traits any further because it's reached the end of the genetic line, probably because of a very high proportion of homozygous genes for its characteristic traits, or "fixed loci" which also happens in founder effect and bottleneck although in this case it happend by mere migration and isolation and inbreeding over many generations. It's not a new species in the evolutionist sense, only by that artificial definition that inability to breed with other populations makes for a new species, which is considered to be a stepping stone to further efvolution. But as a matter of fact it couldn't possibly lead to further evolution because to get where it is required severe genetic depletion. This is what I have to suspect many supposed speciation events lead to in reality. Well perhaps I should be clearer: I'm DISPUTING that idea of evolution. I don't think fitness plays a part in the majority of cases where new varieties develop, I think the mere recombination of genes by inbreeding in a new population of reduced numbers of individuals is all it takes to produce new breeds in nature, or varieties or "species." Mere changed gene frequencies is all it takes, and another thing I'm pointing out that isn't normally taken into account is that changed gene frequencies that are brought about by isolation of a smaller number of individuals from a larger population always involve reduced genetic diversity in ORDER to bring out the new phenotype or variety or species or breed. OK, that is the classic statement of how evolution works, supposedly all fitness-driven, but my argument is that while fitness and adaptation can certainly be seen in nature, it's just as likely or even more likely that the characteristics of the variety lead to the adaptation by finding whatever in the environment supports its traits rather than that its traits are developed to conform to the environmental conditions. That is, all those different finches are insect eaters or seed eaters or I forget the other things they do because new gene frequencies brought about different beak types that made them suited to certain kinds of food, although ALL the environments they encounter have ALL those kinds of food available so it isn't that the environment chose them, it's that their particular beaks chose the particular offerings in all the environments. Yes they are certainly adapted to their food source but not because the environment required it of them. Now of course there ARE such situations where the environment does the selecting, where a certain kind of food simply is not available so the creature must adapt over generations whatever trait does best with the kind of food that is available. Or migration to a colder or warmer climate would cause the best adapted types to develop there too. Of course. I just don't think this is the predominant way such adaptations come about. I don't get the point here. So what? Yes, getting blended does imply a form of selection, so you're right, in reality any mutation is just going to remain one among many traits scattered through the population that maintain the same proportion down the generations if they neither enhance nor threaten reproductive ability. I agree. True, I was wrong about the blending. But I would say here 1) that mere migration or mating preference can isolate a population and develop a new "species," fitness is not necessarily the selecting factor, and 2) that two separate inbreeding populatons would be genetically reduced WITH RESPECT TO EACH OTHER, each having a different set of alleles to the other and NOT having the alleles that are peculiar to the other or they would not have their own particular characteristics. What "diversity" are you talking about? I'm focusing on GENETIC diversity but when someone takes off the "genetic" part of the phrase I'm sure you aren't talking about the same thing. But in this case my point had to do with the homogeneity of the PHENOTYPE, the visible animal, in all those populations of the wild. Humans don't have that much phenotypic homogeneity. But also those are breeds or varieties I'm talking about in the wild so that the overall population of the species, if all taken into account, the grizzlies with the polar bears and all the other types of bears as one species, would have lots of GENETIC diversity all together. It's the breeds or varieties that lose genetic diversity with respect to the mother population and with respect to each other, and not always to any kind of threatening extent. I've never claimed that although some here think I have -- it's only at the extremes that happens and since it's the extremes that demonstrate how evolution comes to an end I do bring it up as part of the argument, but the actual situation of most species in the wild doesn't involve genetic depletion. The grizzlies, although genetically reduced with respect to the overall bear Species and to other bear subspecies, may have quite a bit of genetic diversity nevertheless, so that they could be the progenitors of many new subspecies themselves, but there's no way to tell from outward observation. Sure it can be slow but the whole idea of evolution is that it produces new species, ultimately getting new Species with a capital S. I'm sure you want to include all the other things that go on in nature under the title "evolution" but that just confuses things. The point is that you get new species, because if you didn't you could never get new Species with a capital S if you get my point.

My model, which you doubt I possess, but anyway, my model says that you get reduced GENETIC diversity with the formation of new phenotypes. The formation of new phenotypes could be said to be an increase in PHENOTYPIC diversity of course, with respect to the former population and the total population of bears or humans, whichever you are talking about.Grizzlies would have reduced genetic diversity with respect to the entire population of bears in the world and with respect to the previous population from which it diverged.But whenever there is a divergence of subspecies you get an increase in phenotypes with respect to the total bear population. Increase in phenotypic diversity goes more or less along with decrease in genetic diversity. How could I possibly know and why does it matter?Edited by Faith, : No reason given.Edited by Faith, : typo

You do not know in the majority of the cases that they ARE mutations rather than rare but normally occurring genetic combinations. Since you guys call every kind of "novelty" you identify in genome or in phenotypic traits a "mutation" there is no way to be sure you know what you are talking about.