Evidence for Reduced Genetic Diversity as Necessary Component of Evolution

You want some evidence for the claim that evolutionary processes always involve the reduction of genetic diversity? It's pretty simple, OUGHT to be obvious, and it's all about the reduction of heterozygosity to homozygosity or even less: This is from Wikipedia on Zygosity:

A cell is said to be homozygous for a particular gene when identical alleles of the gene are present on both homologous chromosomes.[2] The cell or organism in question is called a homozygote. True breeding organisms are always homozygous for the traits that are to be held constant.

In nature the same thing applies. Once you get a new variety, a subpopulation that is reproductively isolated from its parent population or other populations of the same species, even the result of a "speciation" event, and especially after it has inbred over some generations, its traits are going to be or become fixed. For a new trait to stick, or continue to characterize the new population, competing alleles for that trait must have been eliminated from that gene pool. THIS IS THE NECESSARY REDUCTION IN GENETIC DIVERSITY THAT ALLOWS A NEW TRAIT TO COME TO CHARACTERIZE A NEW BREED OR POPULATION IN THE WILD, THIS MUST OCCUR FOR A NEW TRAIT TO DEVELOP AND STICK IN A NEW POPULATION.

If they are "true breeding", they will be homozygous for their characteristic traits. This HAS to be true whether the population is the result of natural processes such as natural selection or genetic drift, migration and so on, or domestic breeding decisions.

HOMOZYGOSITY MEANS ONLY ONE ALLELE FOR THE GENE, ALL THE OTHER ALLELES HAVING BEEN ELIMINATED FROM THAT PARTICULAR GENE POOL. THAT'S THE SEVEREST CASE OF DECREASED GENETIC DIVERSITY (except for hemizygosity and nullizygosity, mentioned in the article below) AND IT'S NECESSARY TO GETTING A "TRUE BREED." AND WHAT IS A TRUE BREED BUT A NEW PHENOTYPE OR "SPECIES," A SPECIATION EVENT IN ITSELF, THE SUPPOSED STEP ON THE WAY TO OPEN-ENDED EVOLUTION FROM ONE SPECIES TO ANOTHER ACCORDING TO EVOLUTIONISTS.

Take dogs. If you want a Dachshund you have to eliminate all the alleles that specifically produce Great Danes or Golden Retrievers or Chihuahuas etc. If any of those alleles show up in the Dachshund breeding program you'll get a less perfect Dachshund. They make the breed less than what it is supposed to be.

It works the same way in nature, maybe through Natural Selection but probably more often through random events that simply happen to separate a population into two or more subpopulations. A particularly marked salamander emerges because the other markings are genetically decreased by comparison to those for the new marking. The markings of the last species to develop in a ring species of such salamanders should be genetically homozygous. Same with the genetics underlying the last species in the ring of green warblers and so on. You should find decreased genetic variability and probably a lot of homozygosity, just because this is what evolution DOES.

It's NECESSARY to evolution, and if evolutionists weren't always imagining nonexistent mutations into the mix it ought to be obvious even to THEM. The only mutations that are involved are those that contribute diseases to the mix and interfere with the health of the most genetically reduced populations, even to extinction in some cases.

In nature the introduction of disease elements may simply eliminate a new variety, Natural Selection in operation at its most severe, but if the new variety finds a niche it can adapt to it will survive just as a good domestic breed will.

The new variety necessarily comes through a reduction in genetic diversity. That's how evolution WORKS, really, though such an obvious necessity, that must lead to LESS ability to evolve, is simply ignored by believers in evolution who go on spinning evolution out of imaginary mutations.

To repeat the point: If circumstances are such that the populations remain reproductively separate, meaning without gene flow or the sharing of alleles between them, each will develop its own particular characteristics, and as long as there remains no gene flow or reproductive contact between the populations those characteristics will remain. For them to remain means that the alleles for different characteristics have been eliminated. That's what decreased genetic diversity MEANS. This may amount to actual speciation, but at least certainly at the extremes you do get speciation, where the new characteristics are preserved because there is a complete lack of interbreeding with former populations.

Evolutionists regard bottlenecks as events that interfere with the processes of evolution, but they shouldn't. The elephant seal and the cheetah which were produced by severe bottlenecks -- reduction of their former populations to just a few individuals -- that severely reduced their genetic diversity -- really ought to be considered to be examples of speciation, nature doing what domestic breeders do. Bottlenecks are really just one way new varieties or breeds are brought about in nature or in domestic breeding. ALL the processes of evolution tend in the same direction, genetic drift, migration, natural selection, just not as rapidly. Domestic breeding in the past could be described as the artificial creation of genetic bottlenecks for the purpose of developing desired traits for new breeds. You select the desired character and take pains to breed only with others that possess that character. Since a rigid adherence to this formula also usually brings disease problems into the breed, breeders today take care to avoid the most severe bottleneck methods with the most severely decreased genetic variability by mixing with more vigorous but less desirable animals as far as the target trait is concerned, but if it weren't for the threat of disease, these severe methods would be considered the most reliable way of producing the best breeds. SPECIATION.

Yet here we have RAZD at EvC carrying on as if the evolution processes just go on and on producing new phenotypes or varieties or breeds, even past speciation which he treats as the end point of microevolution and beginning of macroevolution, but afterward the same changes continue without a hitch in his scenario.

What separates (micro) evolution from the macro view of evolution (macroevolution) is the process of speciation, as evolution occurs within the breeding population, and nested hierarchies are formed by speciation events, and macroevolution is just a macro view of what occurs over several generations via evolution and speciation.

If we look at the continued effects of evolution over many generations, the accumulation of changes from generation to generation may become sufficient for individuals to develop traits that are observably different from the ancestral parent population. This lineal change within species is sometimes called phyletic change in species. This is also sometimes called arbitrary speciation in that the place to draw the line between linearly evolved geneological populations is subjective and because the definition of species in general is tentative and sometimes arbitrary.

See, he's simply ASSUMING the open-endedness of evolution, the phenotypic changes just go on and on, a neverending ACCUMULATION of changes. He has no evidence for this, though he has charts that give it an aura of authority that are simply meaningless reflections of his false belief. Actually, they are ILLUSTRATIONS of what he believes, they provide nothing in the way of evidence for any of it. And everything he says is also all assumption without evidence. Dawkins does the same thing with his ridiculous computer models of how evolution works, simply programming in his own bias, his assumption of open-ended changes. Sometimes you'll see an evolutionist acknowledging that reduced genetic diversity can sometimes be a problem but they keep that information off in a separate mental compartment, it's something that occurs only with bottlenecks, in extreme scenarios that interfere with evolution, not with evolutionary processes themselves.

Just for the record, here is the most pertinent part of the Wikipedia article on Zygosity:

Types
The words homozygous, heterozygous, and hemizygous are used to describe the genotype of a diploid organism at a single locus on the DNA. Homozygous describes a genotype consisting of two identical alleles at a given locus, heterozygous describes a genotype consisting of two different alleles at a locus, hemizygous describes a genotype consisting of only a single copy of a particular gene in an otherwise diploid organism, and nullizygous refers to an otherwise-diploid organism in which both copies of the gene are missing.

Homozygous
A cell is said to be homozygous for a particular gene when identical alleles of the gene are present on both homologous chromosomes.[2] The cell or organism in question is called a homozygote. True breeding organisms are always homozygous for the traits that are to be held constant.

An individual that is homozygous-dominant for a particular trait carries two copies of the allele that codes for the dominant trait. This allele, often called the "dominant allele", is normally represented by a capital letter (such as "P" for the dominant allele producing purple flowers in pea plants). When an organism is homozygous-dominant for a particular trait, the genotype is represented by a doubling of the symbol for that trait, such as "PP".

An individual that is homozygous-recessive for a particular trait carries two copies of the allele that codes for the recessive trait. This allele, often called the "recessive allele", is usually represented by the lowercase form of the letter used for the corresponding dominant trait (such as, with reference to the example above, "p" for the recessive allele producing white flowers in pea plants). The genotype of an organism that is homozygous-recessive for a particular trait is represented by a doubling of the appropriate letter, such as "pp".

Genetic Evidence of the Bottleneck at Noah's Flood Part 1

Well, hi de ho, somebody finally decided to try to have a discussion about the claim that the bottleneck of Noah's Flood should have left genetic evidence that it didn't leave. I've many times wondered exactly what evidence they think they would find, so let's hope somebody finally defines it.

In several threads, Jar has brought up the genetic bottleneck argument against the biblical flood and it appears to me to be a slam dunk of an argument. So I thought it was worth expanding on it and teasing out the details.

Sure, go for it.

Perhaps we should start with when creationists think the flood happened (my bold).

When was Noah’s Flood? 1,981 years to AD 0 plus 967 years to the founding of Solomon’s Temple plus 480 years to the end of the Exodus plus 430 years to the promise to Abraham plus 75 years to Abraham’s birth plus 350 years to Shem’s 100th birthday plus 2 years to the Flood. The Biblical data places the Flood at 2304 BC +/- 11 years.
http://www.answersingenesis.org/...v4/n1/date-of-noahs-flood

So this is about 4,300 years ago. (Maybe other dates around that time will be claimed but a bottleneck should still be apparent.)

I sometimes round it to 4500 years ago but 4300 is more accurate though a couple hundred years isn't going to change the evidence anyway.

Because all existing species have descended from so few individual so recently, their genomes should be very, very similar to each other - simply because all members of the same species would be close cousins.

Species that we know have undergone a bottleneck, such as the elephant seal and the North American bison - which were hunted to near extinction - and the cheetah, which appears to have also gone through a bottleneck 10,000 years ago, show this genetic fingerprint. In the cheetah's case their genetic variance is so small that their immune systems have so much in common that skin grafts aren't rejected between individuals.

So is this the sort of evidence you'd be looking for? Many fixed loci such as the cheetah's? Is this the "genetic fingerprint" you have in mind?

Jar's argument goes that if all animals and plants on earth (with the possible exception of some fish which may have been able to survive salinity changes) were reduced to either pairs, or sometimes a few more of each species (I don't see how 'kinds' could make a difference) we would see the bottleneck fingerprint in pretty much every plant and animal alive today.

The bottleneck should only be applied to creatures on the ark. Plants were not systematically saved on the ark but had to fend for themselves, same with sea creatures and apparently also insects and microorganisms.

But we don't. And because we don't it's not possible that virtually every species on earth was reduced to two or three individuals only a few thousand years ago.

And this should just about do it for the evolutionist side of the argument. I wonder if any creationists there will be up to answering it.

This is rather a unique situation; the proof does not rely on having witnesses around thousand of years ago, partial archaeological records, 'inferences' or any of the usual escape clauses of indirect evidence, it's repeatable, direct, clear, present and obvious.

I agree, it's a nice set-up for your purposes.

So what's wrong with it?
http://evolution.berkeley.edu/...o101/IIID3Bottlenecks.shtml
http://en.wikipedia.org/wiki/Population_bottleneck

"What's wrong with it" coming up. Let's see how the thread goes for a bit and then I'll bring on my answers here. I'll post this and then add to it.

===

JAR has now posted his response in Message 3:

IIRC I first presented that idea back in 2005 or 2006 and the beauty of it is that it begins by assuming only what the Bible stories say is true and asks, "If true, what must we see?"

If someone claims that they shot and hit the target, then we must see a hole in the target. If we look at the target and there is no hole, then the claim that the target was hit is falsified.

The test is also independent of when the flood happened; it does not matter if it was yesterday, 4300 years ago or 200,000 years ago.

Regardless of when the flood happened the genetic bottleneck would have been at the same time for every surviving species. The population would have been reduced to at best 14 critters of a kind and at worst 4 critters of a kind.

Actually it was seven and two of the animals and six human beings -- the three sons of Noah and their wives. Noah and his wife had no more children after the Flood so their genes only count in their sons.

But let's not let this go on too far before giving at least a sketchy answer to it: As JAR goes on to anticipate, the answer is in the "super genome" -- but see my previous post in which I've come around to modifying this notion to mean a more fully functional genome in which what is now junk DNA was then alive and contributing many more genes and alleles to the mix.

I also did a post on this some time back as a matter of fact, answering this same challenge from JAR. There ARE markers of the bottleneck in the genomes of all affected, in reduced genetic diversity which is shown in a reduced percentage of heterozygosity for each species.

JAR is anticipating a much more drastic genetic reduction on the order of the cheetah's and the elephant seal's to near-total HOMOzygosity, but those situations occurred very recently and occurred in gene pools that were already much genetically reduced from the time of the Flood after many generations of population splits. In recent times a severe bottleneck is much more likely to reduce many genes to fixed loci, meaning one allele shared by all the individuals of the bottlenecked population, than would have been the case back at the ark. At that time, assuming the much greater heterozygosity of the far more fully alive genome with very little dead or junk DNA, each individual on the ark would have been heterozygous for enough genes to produce all the variations we see today without the specific markers for reduced genetic variability that JAR is expecting based on TODAY's effects.

As I report in that post I linked above, today's human population has about 6.7% heterozygosity, about which I report one researcher said:

a single human couple with just "6.7% variety" could produce 10 to the 2,017 children ...before they would have to produce an identical twin..."

He goes on to say that the whole spectrum of skin color we see today would be easily produced IN ONE GENERATION with just this 6.7% heterozygosity for that trait. Combining that with the same breadth of possibilities for size, hair or fur color, bone type, muscle type, and so on and so forth, would certainly yield an enormous variety of individuals within each created kind or type.

So I figure this 6.7% heterozygosity is what remained on average to all creatures after the Flood, or perhaps it was somewhat more then and has decreased since then. It's still enough to produce enormous variety, everything we see today.

THEREFORE, at least that much heterozygosity was represented in the passengers on the ark, and since that percentage is standard today there would be no reason to expect to see the usual drastic markers for a bottleneck of the sort that produced the cheetah.

That is, this percentage of heterozygosity we have today IS the marker of the Flood bottleneck. Because of population splits since the Flood that would have reduced it even further, it was no doubt much higher then than it is now, but BEFORE the Flood it would of course have been much much higher. I don't know whether to suppose that ALL genes could have been heterozygous back at the Creation or not, and that would include all the genes that are now in the junk DNA graveyard, but it's not beyond the realm of possibility. For that 100% to have been reduced to 6.7% of the 5% of living DNA still in our genome is a perfectly reasonable expectation of the degree of loss of genetic diversity in the Flood bottleneck.

And THAT's your marker OF the bottleneck. And as I say in that post and imply above as well, so is the great percentage of junk DNA in the genome as well.

There are your markers. But you know what, I know that thread is going to go reeling on without acknowledging this idea. I'm easy to ignore out here in cyber space.

So there really isn't more to say on this subject. However, I'll continue to keep tabs on the thread, including the rest of JAR's post:

But wait, there is more...

one possible way around it has been to invoke some super genome, that the pre-flood genome was somehow different and so allowed for greater variation.

Well, there are two major problems there.

First, even if there was some super genome if the Biblical flood stories were true there would still only be at best 14 copies of it to work with and that is still a bottleneck.

True, but since the mere 6.7% heterozygosity still available in our genome today can account for enormous variety, and AT LEAST that much was represented by the few individuals of each species on the ark, a bottleneck then would have not been reduced to anything like the genetic depletion we expect today. Therefore you are looking for something that fits only your own limited imagination rather than what would really have been the genetic result of such a bottleneck. Just as the early creationist geologists and all of today's geologists persist in looking for evidence of the Flood in all the wrong places.

Second, we have genetic evidence from humans that date to before the 4300 years ago date, from as far back as 30,000 years ago and as far back as 14,000 years ago in the Americas and there is no sign of any super-genome.

I think these two lines of reasoning are pretty solid.

Well, here a creationist simply parts company with the "sciences" that take their mere conjectures about time to be fact. Sorry. The Flood occurred about 4300 years ago and the Creation about 6000 years ago and your age reckonings are nothing but delusion.

And I'm going to skip most of JAR's usual debunkeries of the Bible which usually tend to the blasphemous, and go on to:

In both myths lots of critters get killed, in the myth found in Genesis 6 it seems to be talking about land animals and birds while the myth found in Genesis 7 goes even further and wipes out all living things.

If we play mix and match and take the best scenario from each of the myths we might be able to claim that only the birds and land animals were wiped out based on the passage from the Genesis 6 story and that we have the larger saved population found in Genesis 7.

Based on that mix and match game set we have a situation where all land animals and birds found today will be descended from a population that consisted of at most fourteen critters (seven pairs of clean animals and birds) and at worst case four critters (two pair of unclean animals).

No, take the smallest numbers as I have and only for passengers on the ark, six humans, two unclean animals and seven clean (and remember that most of the clean would have been sacrificed to God by Noah after the ark landed and not have passed on their genes). Sea creatures and plants and others no doubt also perished in great numbers off the ark but we don't have the numbers to calculate in their case.

As for the passengers on the ark, the much greater percentage of heterozygosity in the pre-Flood genome even reduced to a few individuals still accounts for all the variety we see today.

Now that is what I would call a real bottleneck.

We know we can see bottlenecks in the genetic record; a great example is the one in Cheetahs but we even see them in the human genome and most other species.

BUT...

If the flood actually happened we would see a bottleneck in EVERY species of animal living on the land and EVERY bird and EVERY one of the bottlenecks show up in the SAME historical time period.

Talk about a big RED flag.

Yup you're expecting to see the same situation as in TODAY's bottlenecked populations, the extreme homozygosity even to majority fixed loci, instead of the bottleneck markers that really DO exist, the mere 6.7% heterozygosity and the 95% or more junk DNA.

That bottleneck signature would be something every geneticists in the world would see. It would be like a neon sign, Broadway at midnight on New Years Eve. It would be something even a blind geneticist could see.

So it seems to me to be a very simple test that will support or refute the Flood.

If that genetic marker is there in EVERY species living on land or bird of the air, then there is support for the flood. It does not prove the flood happened but it would be very strong support.

If on the other hand that genetic marker is NOT there, then the Flood is refuted.

Good try but the marker IS there, in fact TWO markers are there, but you miss them because your expectations are wrong.

And for the second argument see the thread Looking for the Super-Genome. -And it ain't found.

Well, now I do have a different idea of what that original genome would have looked like by which I would expect to find a pre-Flood genome with hardly any junk DNA and a majority of heterozygous genes.

The relevant question is whether it's possible to SEE the genome of ANY creature that lived before the Flood or not, and as far as I know they're all fossilized or destroyed and their DNA is not available. JAR's favorite "Oetzi" is most certainly NOT contemporaneous with Adam and Eve but lived after the Flood despite the preposterously dogmatic claims for his age. He was found in the Alps but his DNA shows him to be related to Corsicans, who most certainly did not exist before the Flood. This is all post-Flood terrain that's being described here. The Alps also did not exist before the Flood but like all the high mountains were formed by tectonic forces set in motion along with the other geologic phenomena associated with the Flood event.

In any case the markers for the Flood bottleneck ARE apparent in today's genomes if 100% or near-100% heterozygosity and no junk DNA characterize the original "super" genome.

How the cheetah, living proof that evolution is not possible, becomes just another figment of the evolutionist imagination

Hey, I'm honored, mentioned by Iblis in a post at EvC, of course the usual nonsense argument and I'm not there to defend myself but that's OK. There is no defending yourself at EvC if you're a creationist. The thing about evolutionism is that it can morph in any direction it likes in order to answer you because it's all a fantasy. If you say something that seems to challenge the theory, amoeba-like it just extends a pseudopod to gobble up the challenge -- glurrrp -- and everybody's happy.

And this is a case in point.

Faith used to back her affected agrument by incredulity with specious appeals to "genetic meltdown". Her favorite example was the amazing cheetah.

Lessee, of course you must use all the most derogatory terms you can think of to poison the well against the argument for starters, such as "affected" and "specious," to be sure nobody could possibly think the argument had any merit. Oh and be sure to call it an "argument by incredulity" even though it is no such thing -- that's SUCH a no-no.

I also don't recall ever using the term "genetic meltdown" so it shouldn't be in quotes in reference to my argument.

Now he goes on in a way that is rather hard to follow, kind of a word salad approach that serves mostly to obscure and in any case doesn't get anywhere near the argument I was always trying to make by referring to the cheetah:

He's had it rough as the poster-child for reduction of genetic diversity. Due to depopulation, isolation and inbreeding his genetic variability is so low that skin grafts between unrelated animals do not result in immunological rejection! And so on, there are a lot of lovely fables in this area.

IS that a fable? I don't think I ever used that particular example but everything I've read about the cheetah does say that the genetic variability IS so low that individuals are almost like clones of one another. Is he trying to dispute that even after declaring it?

But contrary to popular belief, this is nothing new for the cheetah.

Contrary to popular belief? Whose belief? I never said it was "new?" What does its being new or old have to do with anything? The point is that the cheetah is a prime example of extremely reduced genetic variability. He seems to affirm this yet also try to deny it. This is a very confused piece of writing.

Well, now here comes the Evo Fairy Tale. Get some popcorn, pull up a chair:

It began thousands of years ago, toward the end of last ice age,

Yes, long long ago ...

in a fairly ordinary genetic bottleneck.

... in a land far far away ...

Did anyone ever suggest the bottleneck was not "ordinary?" The point about a bottleneck is that it eliminates a bunch of genes all at once, leaving a very few individuals to form a new population with the reduced genetic variability they share, whether it's an "ordinary" or extraordinary bottleneck, whatever that might be.

And as result of this process, the cheetah has become the least "feline" of all the big cats.

Well, it has a smallish head as felines go but otherwise it's plenty feline it seems to me. But apparently saying it's less "feline" is supposed to imply that it's an example of evolution. Sigh. Are we getting anywhere with this little dissertation? Doesn't it seem to be wandering around trying to obscure the issue?

So now we go from this completely subjective notion that it's less feline looking to this HUGE jump:

In another million years or so, he may look something like this [here we get a picture of -- a hyena? A doglike animal with some cheetah-like coloring and markings]

Oh brother. Because the cheetah just sort of looks less feline to this guy it's evolving and is going to look even less feline in a million years. Sigh.

The point about such drastically reduced genetic variability is that EVOLUTION HAS COME TO A STOP. That is the point of using the cheetah as an example. The cheetah is NOT EVOLVING. It's reached a genetic dead end. When you have no new genetic possibilities there is simply no direction in which the animal COULD evolve. It goes on producing individuals that hardly vary at all from each other, to the point that they are truly like clones. You CANNOT GET EVOLUTION FROM THAT POINT.

A bottleneck is what happens when for some reason you have just a few individuals inbreeding among themselves to form a new variation of a species. A bottleneck is simply the most drastic way animals get "selected" -- randomly in this case -- and isolated, these being the "mechanisms" or conditions that bring about new gene frequencies, which is supposedly the basis for evolution. And it IS, it is the basis for MICROevolution, or the variation that commonly occurs from generation to generation in any species. If part of a population gets isolated from the rest it develops characteristics to some extent different from the former population with its own reduced gene pool. But it WILL have a reduced gene pool, it WILL have reduced genetic variability compared to the previous population. A bottleneck will simply bring about a DRASTICALLY reduced genetic variability compared to the usual reduction because it involves so few individuals. This is what makes such examples the best for making the point about how evolution comes to an end by simply following out the normal processes that create new varieties, or microevolution. ALL reduced populations tend in the same direction of reduced genetic variability but the extremely reduced populations are where you see the tendency itself in action, where it's hardest to ignore it, the tendency, that is, toward the complete inability to evolve further somewhere down the road.

Of course fantasy can surmount any obstacle thrown up by reality, and here we have Iblis totally ignoring this point and assuming that the cheetah is going to go on evolving although it doesn't have the genetic means to go on evolving:

The misadventures of these fellows actually provides the key to your whole puzzle. You see, when the gene pool is large and conditions remain stable, the overwhelming majority of even the effective, non-neutral mutations are quickly lost in the shuffle. They are outnumbered and as they provide no selection advantage, there is no reason for them to be preserved.

If mutations are going on at the rate they assume, then there is no such thing as their not having an effect. A mutation is a change in a gene, it is a substitution of a new coding sequence for another. If it has no effect all that means is that it has no detectable effect, no effect that they know of. But the very fact that a coding part of the DNA has been changed means that SOMETHING HAS CHANGED in whatever that segment formerly coded for. It can't be a good thing that a formerly coding sequence no longer codes for whatever it used to code for. At the very least something has been killed, some part of the organism no longer functions, a very tiny hardly discernible part no doubt, something beneath the detection capacity of the instruments available, but how can the death of a coding portion of DNA ever be just "neutral?" And most mutations supposedly have this non-effect. But that means that most mutations are killing off genes coding bit by coding bit. This is no doubt how "junk DNA" gets formed and there's an awful awful lot of junk DNA in the genome of most creatures, certainly the human genome. But that's a whole nother subject.

When the gene pool is greatly reduced however, either due to large-scale changes in the environment in terms of selection factors or to the spreading out of outliers of a population into a new area or niche, this changes. The cow's primary source of genetic diversity is, other cows with somewhat different genes.

Exactly, this is how genetic diversity is maintained in most large populations of any animal. Individuals vary from each other, they have different genetic possibilities that can combine with those of other individuals to create the variation that shows up in the next generation.

The cheetah's, though, is mutation.

Uh huh. Mutation is the only thing left to the cheetah, and this is true. But consider the RATE situation now. How many of the expectable mutations provide any kind of change that could be useful to the animal? Actually, it's pretty much zip. You get all those "neutral" mutations and you get deleterious mutations. Those are known. The useful ones are purely imaginary.

Each new trait produced by mutation is valuable to a reduced species and likely to be preserved

Pure fantasy. There ARE no new "traits" known to be produced by mutation. All that is KNOWN to be produced are degenerative changes and "neutral" changes, that, as I point out above, aren't really neutral because they DESTROY genes.

resulting in large-scale morphological changes over a relatively short period of time. Still in the high thousands and millions though.

Man these guys love their theory. They NEVER have to come down to reality and actually PROVE anything, they're quite content to affirm the fairy tale of beneficial mutations that drive evolution even in the face of EVIDENCE that, as in the case of the cheetah, evolution is simply no longer possible.

And this is the main factor underlying Gould's "punctuated equilibrium". For ten million years, everything is fine. Then things change; and when they do, things change. Eerie. But not mysterious, simple statistics.

Eventually you'd think a brain would simply implode from the strain of having to invent all those fictions to support all the imaginary notions that support the imaginary theory.

But thanks for the mention, Iblis, gave me the opportunity to restate my favorite argument.