Evolution Requires Reduction in Genetic Diversity

COULD happen that way, OK, I'll give you that. But you're making a hypothetical case you can't prove. We do need to have some kind of experiment to prove this one way or the other, and it would have to involve DNA reading.I wish I could lay out how the mere processes of repeated migration, isolation and inbreeding lead to "speciation" but I'm not able to juggle the genetic possibilities well enough.But how about the cheetah for an example. I know you'll object that it was the result of a bottleneck, but their main genetic characteristic is their many fixed loci, which is also what I expect to see at the end of a series of migrations, isolations and inbreedings. I haven't heard anything about mutations being the cause of their inability to interbreed with other cats, but simply the effect of the bottleneck on their genome, which changed it sufficiently for it to be a mismatch with other cats. I'm sure there must be plenty of examples of what I have in mind out there but I'm not very good at finding stuff. Edited by Faith, : No reason given.

Even assuming that this is correct, you are describing a change that occurs after the populations split. Accordingly the change is not the cause of such splits. So what is the cause? How about all of the stuff discussed in that article that you claim is wrong? How about the list of examples I gave in my last post?Further, lots of things cause frequencies to drift even without a split. How about changes in the environment or genetic drift. Clearly you are not describing a cause and effect relationship. At least it is clear that you are not providing the sole cause for changes in frequency.And you still are not addressing the point.Your claim is that a remix of gene frequencies can cause populations to become incapable of inter breeding. I have pointed out that you cannot produce any mechanism for such, and your response was that mutations produced the same thing as a reshuffling. Presumably you ducked answering the question directly because you did not have a mechanism.After I gave you reasons why mutations don't simply provide a new allele for a gene, and thus differ from simply remixing you haven't made a single effort to respond to the hole in your argument that I pointed out. Nothing you say here does any such thing except change the subject, refuse to respond, and then claim that I am the problem.I suspect that the problem is that you have no argument. You seem to want to talk about everything else except the petard you are hoisted upon. Well just stay up there, with your feet dangling.Edited by NoNukes, : No reason given.

Explain how this is not hogwash. Where do the new set of alleles come from if there is no mutation? Total nonsense.

I suppose if you want to create your own definitions.Migration is the movement of individuals between populations. Migration is gene flow, it does not select anything, it moves genes between populations. It is not just movement of genes out of a population to form subpopulations but it also involves migration INTO populations. Genetic drift is more like "random selection" as you call it. It works by eliminating individuals in a population regardless of their genotypes or fitness. It most certainly does mean something, but no, fitness doesn't cause genetic change, selection acting on fitness causes genetic change. It can and has been demonstrated in the lab and in field experiments. But where is the evidence of this? These definitions have come about because of work done by biologists studying these processes. You are making up new definitions to accommodate your view; you can't define yourself into being right. Modes of speciation are fairly controversial in evolutionary biology. The major distinction is the amount of gene flow present between the main population and the subpopulation. Allopatric speciation has no gene flow because of a physical barrier. Peripatric has isolation of a subpopulation but no physical barrier so there is still potential for gene flow. In Parapatric the subpopulation is not isolated and there can still be gene flow between the main population and subpopulation. For Sympatric the subpopulation forms within the main population so there is potential for significant gene flow. So potential for gene flow is the key distinction between the modes of speciation.ABE: The question for the these different modes of speciation then becomes - how do you prevent or minimize migration (ie. gene flow) between the main population and the newly formed subpopulation? Allopatric makes sense - the physical barrier prevents migration, but for the others the answer is not so clear cut.HBDEdited by herebedragons, : No reason given.

Hypothetical, yes - for simplicity sake. Can't prove? well... Speciation by distance in a ring speciesAbstract:

quote:

---

Ring species, which consist of two reproductively isolated forms connected by
a chain of intergrading populations, have often been described as examples of
speciation despite gene flow between populations, but this has never been
demonstrated. We used amplified fragment length polymorphism (AFLP)
markers to study gene flow in greenish warblers (Phylloscopus trochiloides).
These genetic markers show distinct differences between two reproductively
isolated forms but gradual change through the ring connecting these forms.
These findings provide the strongest evidence yet for ‘‘speciation by force of
distance’’ in the face of ongoing gene flow.

---

Look this paper over and give me your critique. Of particular interest is Fig 2.Keep in mind this paper is a bit older and they seem to lean toward the sympatric or parapatric modes of speciation. More recent work has suggested that there probably was isolating barriers between populations at one time in their evolutionary history.HBD

The above statement makes no sense. Calling something rare is an acknowledgement that it does occur.And of course none of that explains how reshuffling of alleles that already existed in a population creates a mating incompatibility. You've acknowledged that mutations could have the effect, but that does nothing to answer the question. Edited by NoNukes, : No reason given.

Statements like this can seem Lamarkian to people who are looking for that in the theory of evolution. Fitness just measures the ability of a phenotype and its supporting genetic variety to survive. Disappearing genotypes change the genetic make up of the population because of their absence. But fitness is not a means for introducing genetic variety.Why in the world the role of fitness would be a point of attack for the theory of evolution is quite bizarre. Unlike some of the other issues, the process of natural selection is easily observed. I suppose any port in a storm...Edited by NoNukes, : No reason given.

Well, here are they AGAIN.It is quite annoying I must say.Here are the major assumptions of your position:

1. There has been a decline in genetic diversity last 4,500 years in the genomes of all species
2. There is no such thing as genetic innovation (mutations acted upon by natural selection leading to new genes or the loss of genes)

No. 1 cannot be empirically backup up by you. That is, until now I’ve seen nothing yet. There are several ancient genomes sequenced as I pointed out to you: Denisova, Neanderthal, Heidelbergensis, ancient Homo Sapiens. These genomes are also mutually compared by geneticists. All those genomes are genetically very close. As a matter of fact, Svante Pbo and his teams (and others as well) found that at least Denisova, Neanderthal and Sapiens have interbred. But, anyhow, we HAVE the genomes sequenced of very old hominids. And these show you ARE WRONG. Because when Denisova, Neanderthal, ancient Sapiens genomes turn out to be very similar to extant human ones, the apparently weren't many genes silenced and turned into junk DNA.Moreover, John Sanford tried to prove empirically for a decline in genetic diversity in genomes. He utterly failed. Even cheating on the work of others couldn’t help him.Now, I already provided this stuff 4 or 5 times, if not more.May I FINALLY have you elaborations on this?No. 2 is directly refuted by the Lenski experiment, along with an abundance of similar experiments on both bacteria and sexually reproducing eukaryotes like beetles, fruit flies and yeast. I even spelled out the results of Lenski’s experiment in post Message 431. Percy had to remind you to provide an answer too.As these experiments refute your assumption, may I have your elaboration on these? Now I already asked this 4 or 5 times. When do we get the answers?But there are more questions unanswered by you:

3. If many genes were silenced and turned into junk DNA, which traits were lost than? Because your position implies that an astonishing number (accounting for at least a substantial part of the current 95% junk DNA) of different traits must have been lost.
4. Adam and Eve both could only have a maximum of 4 alleles and the Noah's crew a max. of 16, while in extant human populations, some genes can have as much as 59 alleles. How would you explain that while you are assuming a steady DECLINE in alleles?
5. Genetic, empirical studies on pseudogenes (cetaceans, platypus, mammals, toothless animals, chickens, primates, humans etc. — all provided to you) show that pseudogenes are telling the story of evolution: the loss of traits due to changing environmental pressure sand conditions not favouring them anymore — backed by observations of the fossil record, embryology, recurring atavisms, etc. etc.
6. The fossil record shows that life greatly changed throughout the eras. The different geological formations all have their own, quite distinct biodiversity. In ANY of the Lower Cambrian formations EVER examined (and this has been done thousands of times) you will find even ONE single specimen of land plants, fish, amphibians, reptiles, dinosaurs, bird or mammals. Hence, life has changed. This implies a vastly and continuously genetic innovation. To avoid unnecessary diversions here: WHERE did I mention dates??????

And of course this very old point, form the very beginning when I joined the debate here:

7. The correct way to conceive evolution in ring species is NOT "....you are getting a series of subspecies by the reduction of genetic diversity from subpopulation to subpopulation rather than "speciation" at any point as evolution defines it." BUT: "....you are getting a series of subspecies by the dispersion of genetic diversity among the subpopulations and eventually resulting in "speciation" as evolution defines it."
   THAT is what REALLY happens.

Now, in post Message 461 I already remarked: You may also go back to my post Message 462. Or Message 474. Or Message 479. In the latter I wrote: Or maybe you try post Message 522. Or Message 555?You are also found to be profoundly wrong on the effects of population bottlenecks.

dupEdited by Faith, : No reason given.

Have you completely missed the point? The new set of alleles refers to the same alleles in new proportions or frequencies. If you aren't getting that much there's no communication here at all.Edited by Faith, : No reason given.

No change in definitions at all, change in assessment or analysis. That's ridiculous, they are two engtirely different things with entirely different results. One is additive, gene flow, the other is selective or subtractive. But if both are described by the same term that's just another case of evolutionist confusion. So shall I call what I'm talking about EMIGRATION perhaps and the other IMMIGRATION? That would make more sense. It eliminates alleles the way all the processes I'm calling selective do, and so does migration/emigration as I've been saying all along. Yes, random selection in both cases. Oh it isn't that there aren't adaptations but my argument is that this is far from the major cause of change claimed by the ToE. Peppered moths and pocket mice are the only examples I can think of and they don't form permanent new subpopulations, they alternate according to the environment. As I've been arguing, which you may not have noticed, such famous examples of adaptation as Darwin's finches more likely formed through mere migration, or random selection of alleles, than in response to the environment.

No, I'm thinking through the realities that the ToE relegates to assumptions. The ToE says natural selection so everybody assumes natural selection whether it's involved or not. And speaking of evidence let me know when you have some for your hypothetical mutations. Potential for gene flow is meaningless; either there is gene flow or there is not. Why would you try to minimize it? It's a reality, just take note of it and make your focus the ones without gene flow if you want the least complicated view of speciation. But I do not use the word migration the way you are using it, it's confusing. But if I have to now I'll say emigration. As I use it it's a form of selection. it's unimportant. Gene flow may occur or not for many reasons.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

Of course they DO OCCUR.
As demonstrated by me and others here abundantly:

1. Leski's E. coli experiment
2. similar experiments on other bacteria
3. experiments on sexually reproducing eukaryotic species like beetles, yeast, fruit flies and genetic studies on dachshunds - only SOME of them
4. fossil record

Well, shortly, the dozens of questions and points dodged by you.I am afraid I also have to explain evolution theory to you - again.The low frequency of beneficial mutations is quite irrelevant.
The reason for this is natural selection.
Beneficial mutations are favoured.
The reason for this is BECAUSE they are beneficial.
And "beneficial" or "deleterious" are defined in terms of fitness: survival and/or reproduction chances.Deleterious mutations are weeded out. That's why in most species only a rather tiny part of the newborn eventually will make it and reproduce themselves, passing their genes on to the next generation. In frogs the vast majority of the fertilized eggs will survive. In mice likewise. Even in humans fertility research found that only 15% of all conceptions end up in the birth of a living child. Then the selective pressure persists. In all species a considerable percentage of newborns will not manage to survive up to reproduction age. And when that hurdle is taken, sexual selection starts, leaving especially many male animals abiding their lives without ever passing their genes to the next generation.Many studies even revealed that there is a direct correlation between the selective pressures animal species are experiencing within their habitat and the number of offspring: the more fierce the pressure, the more offspring.Beneficial ones though are favoured. they will not be weeded out by natural selection.Let's do some calculations:

• assume we have a population of, say, humans, of 100,000 individuals. Very moderate assumption but deliberately to make my point by using very conservative estimates;
• let's assume mice have the same mutation rate as humans, that is 70 per newborn (as observed in diverse genetic studies);
• let's also assume a stable population with no growth or decline - that assumes each generation will bring forth 100,000 offspring;
• now here we go: in the first new generation 100,000 newborn X 70 = 7,000,000 mutations have been accumulated in the population genome. In 5000 generations this adds up to 1,000 X 7,000,000 = 35,000,000,000 mutations. In other words: after just 5,000 generations (about 10,000 years, evolutionary spoken just a blink of the eye) the WHOLE human genome (35 billion base pairs) could potentially have been altered ENTIRELY.

You see, in statistics we have the law of great numbers. It tells that, how small the odds for a particular event may be, if the number of trial is large enough, that event MOST LIKELY will occur.

You better start to read Darwin before starting this - I am sorry to put it this way but your attitude is getting terrible annoying here - TATTLING and misrepresenting of the things he wrote. Here you go: http://darwin-online.org.uk/content/frameset?viewtype=tex....Darwin described very PAINSTAKINGLY and in TERRIBLE detail how the phenotype of the finches responded to the different ENVIRONMENTAL conditions.BECAUSE when populations of animals migrate, they move into ANOTHER ENVIRONMENT with different conditions and selective pressure to cope with. Hence, finches that flew from one island to another were found to adapt to the conditions over there. Other food sources but lacking the ones in their former homeland. And adapting they did. Darwin painstakingly noted how the different forms of beaks perfectly match the different food sources the distinct finch species thrived on.This kind of field observations and even experiments on the effects of natural selection count into the the hundreds of thousands - and I think I do not exaggerate.

I'm not sure how it seems Lamarkian... sort of anthropomorphic maybe, seeming as though these forces are acting purposefully. Right, fitness doesn't change genetic make up but selection does - acting upon the relative fitness of individuals.An important point to this discussion is how the various forces affect genetic diversity. Here is a table that helps explain it:

	Variation within subpopulation	Variation between subpopulations	Affect all loci
Mutation	increase	increase	No
Migration	increase	decrease	Yes
Drift	decrease	increase	Yes
Selection	increase/decrease*	increase/decrease*	No

(Adapted from: Conner and Hartl (2004). A primer of ecological genetics. Sinauer Associates)* Selection would most often tend to decrease variation except in cases such as heterozygote advantage were both homozygotes are being selected against in which case would tend to increase variation. I think the main point of contention, at least with creationists, is the idea of "survival of the fittest" which seems malevolent to them - especially when applied to humans. I don't particularly like the phrase myself as it misses the nuances of how selection and fitness actually work.HBD