Molecular Population Genetics and Diversity through Mutation

You are seriously delusional if you think your little formula is any kind of answer to what I've been arguing.Edited by Faith, : No reason given.

Well, I and everyone else reading your innumerable threads on this subject understand you to be claiming that evolution requires a loss of genetic diversity and that this depletion must necessarily bring evolution to a halt when the genetic diversity runs out. Because that is what you keep saying. If your argument is actually that carnivorous petunias are stealing your elbows, then you would be well advised to use different words from those you have hitherto been employing.

Well, I and everyone else reading your innumerable threads on this subject understand that mutation increases genetic diversity. Because it does. Edited by Dr Adequate, : No reason given.

No it doesn't and if you understood the argument you'd know why it doesn't.

Unfortunately Faith, reality trumps any argument. It does not matter whether or not anyone understands your argument when reality as been proving you wrong for billions of years.The mechanism that increases diversity is mutation.

No amount of arguing that a process that by definition increases genetic diversity doesn't increase genetic diversity will stop it from increasing genetic diversity.

Right, mutations provided the variability and the breeders determined what variants were desirable. If you remember the picture of the dog skulls I posted a while back the bull terrier is in the middle (B) from 1931 (Top), 1950 (Middle), and 1976 (Bottom).It shows that the changes occurred over a period of 45 years and were incremental. This is important because it shows this wasn't due to a single, large scale mutation but a series of shifts in expression. Another thing that I didn't want to bring up with Faith (but I think you can handle it ) is that often times a undesirable trait will hitchhike along with a desirable trait due to linkage (Jargon: linkage means that genes are located very close to one another on a chromosome and are inherited together) and then end up fixed in the breed. Sometimes these inherited disorders can be bred out by crossbreeding and then backcrossing until the normal allele is fixed in the breed.

quote:

---

Purebred Dalmatian dogs are all homozygous for a mutation in SLC2A9, a gene that encodes a membrane protein involved in uric acid transport [77]. This mutation appears to be closely linked to a locus controlling coloured spot size in the Dalmatian coat and probably rose to high frequency during selection for a distinctive spotting pattern in achieving breed standard. Because of this mutation, Dalmatians are susceptible to hyperuricosuria and formation of urinary calculi that can obstruct the urinary tract (a life threating complication) and which may require surgical removal.

​

To correct this problem, a Dalmatian was outcrossed with a Pointer homozygous for a functional allele at SLC2A9 and then successive backcrosses to the Dalmatian line were performed [78]. As shown in Figure S1 of Bannasch et al. [78], this resulted in dogs that were heterozygous for the mutation (and therefore excreted only low levels of uric acid) but of predominantly Dalmatian genetic background. The backcross dogs descended from the original Dalmatian x Pointer cross have been registered with the American Kennel Club in the United States and meet the breed standard. As seen in Figure 3, after five generations of backcrossing to the original breed, the genetic contribution is 96.9% from this breed while by ten generations it is 99.9%.

---

The challenges of pedigree dog health: approaches to combating inherited diseaseHBDEdited by herebedragons, : No reason given.

quote:

---

Aren't you supposed to be a genius? You are certainly obtuse for a genius. The mutations don't count because they would only function as normal alleles anyway, which I'm arguing have to be reduced in the formation of a new species or breed

---

Seeing something that you seem determined not to get isn't being obtuse.The simple point that you keep missing is that an increase followed by a reduction does not have to be an overall reduction. This point has been made again and again to you, and yet you have never made a valid case for an overall reduction. So getting angry, telling people that they don't understand or worse calling them "delusional" simply amounts to bullying.Again let me explain the general outline of the process as I see it:Additive and subtractive forces are in dynamic equilibrium. As the balance of the forces shift, so genetic diversity will rise or decline until a new balance point is reached. The cycle of speciation is as follows:1) we start with a large population where overall diversity is relatively high - the additive processes are relatively strong (large population size) while drift is relatively weak, and selection is not especially strong.2) A small sub-population is split off, weakening additive processes (small isolated population) with strengthen drift and often selection. This population diverges and becomes a new species.3) The new population is successful and starts increasing in size altering the balance again (mutation becomes more important, drift starts to weaken, selection is very weak)4) As the new species approaches the success of the ancestral population, so its genetic diversity will rise to the same level as the old.I know that you disagree with this scenario, but you have not offered any sound reason to reject it, and it is more consistent with the evidence we have than your views are. And yet you do not even seem to acknowledge it.

quote:

---

Does it ever occur to you that you really might be enslaved to a false worldview?

---

Hardly a topic that we could do justice to without derailing the thread. Are you up for a Great Debate thread on the matter ?

There are no areas of reality that are beyond scientific testing. This is science's job. If you can show me a reality that is not being examined by science, I'll test it myself for you. Yes we know It's not a single lie though is it Faith? If it was a single issue, it's vaguely possible that it could be wrong and if it was wrong it would be corrected - because all errors in science ultimately get corrected.It's actually multitudes of 'lies' in all independant scientific disciplines that all rather miraculously converge on a single 'truth'. So physics, astronomy geology and biology all provide supporting evidence for an old earth and none for a young earth. Are all the millions of scientists involved in a massive conspiracy to corrupt and lie about everything from Rocks to space travel? It's pure fantasy Faith, it's utterly impossible for you to be right and literally millions of man-years of cross-disciplinary, peer-reviewed science to be totally wrong in every aspect of its work. If it was wrong great chunks of our technology would not work. Even you at your deepest level of denial and delusion must know this.

To get a new subspecies, species or breed requires the loss of genetic diversity. If it isn't lost or at least reduced, you don't get a subspecies, species or breed. In nature the purest way this occurs is by geographic isolation. Domestic breeders do it by intentional mating. An increase in genetic diversity in either case will blur the emerging phenotypes, and as long as reproductive isolation is maintained there is no reason to have an increase.The occasional mutation, assuming it gets expressed as a phenotype, is easily removed from the breed. But most won't get expressed as phenotypes. Mutations that do that are rather rare as I understand it. And most are something neither nature nor the domestic breeder would find helpful anyway. You get a breed or a new species by LOSS of genetic diversity. That's how it happens.If you don't want a breed you don't have to have one, you can have all the genetic diversity you like, but enough to make up for the loss required to bring out a new breed would destroy the breed entirely. If that's what you want as a breeder, you can have it, you just won't have your breed, you'll have something else.In nature if gene flow between populations continues while a population has at least partial reproductive isolation, you may get a recognizable breed, but reproductive isolation that prevents gene flow should bring out the most dramatic new phenotypes.In other words if you DO get mutations as you expect they'll increase the genetic diversity somewhat to change your species or breed, and if it's enough mutations to make up for the loss in arriving at the new species or breed you'll just not have that species or breed at all. You'll be back at Square One as far as evolution of new species goes.Possibly the blue wildebeest emerged from the black by some of the black simply getting separated from the parent black population for some number of generations while their collective new gene frequencies brought out the blueish coloring, the new body build and the new antler style. Some gene flow might not impede the process too much but the ideal condition, or at least the clearest condition to explain, is complete reproductive isolation for producing the new species of wildebeest.It's a very simple and obvious formula: losing genetic diversity is what gets a new subspecies in the wild or a breed in domesticity. There's no problem with this unless you lose a LOT of genetic diversity. And a new species/population such as the blue wildebeest, could in fact be stable for hundreds of years. This is all hypothetical, I'm talking about how it could have happened. Reality is usually messier, of course, involving continued gene flow for instance, but the trend that brings out new species is the LOSS of genetic diversity.If you have a large population with lots of genetic diversity and many viable mutations, it will be a motley collection of many phenotypes. It could only become a new species if selection or some kind of reproductive isolation favored a particular set of phenotypes out of the whole collection of phenotypes, over many generations, creating a new subpopulation with its own characteristics, perhaps even within the greater population. And that subpopulation will lose the genotypes for the NONfavored or unselected phenotypes, as those for the favored/selected come to characterize the new subpopulation. There is no way to get a new phenotypic presentation without such a loss.I really don't know if you are obtuse or willfully pretending to be. If pretending, that's understandable, of course, in a diehard evo who couldn't bear to find out the ToE is wrong and there is a God who constructed this biological pattern, because this is definitely a pattern that contradicts the ToE and shows that it could never work. Edited by Faith, : No reason given.

Instead of insulting people who disagree with you, perhaps you should try arguing for your claims. Especially:

quote:

---

In other words if you DO get mutations as you expect they'll increase the genetic diversity somewhat to change your species or breed, and if it's enough mutations to make up for the loss in arriving at the new species or breed you'll just not have that species or breed at all. You'll be back at Square One as far as evolution of new species goes.

---

It's pretty unlikely that you'd get the exact mutations needed even to restore the lost phenotypic variations (of a typical case - phenotypic changes are not essential to speciation) let alone restore interfertility.And yet if we still have a phenotypically distinct population that does not interbreed with the parent population, then of course we have a new species. That should be obvious. So why would it be "obtuse" to reject your claim ? On the face of it, it is an obvious falsehood.

In addition we have documented outwardly similar results and even lost and regained functions but where the mutations leading to the changes were entirely different than the original or even other visibly similar sub populations. One great example even discussed in this very thread are the desert pocket mice where the dark sub-populations are genetically different.Edited by jar, : fix attribution

Please don't attribute my words to Faith