Evolution Requires Reduction in Genetic Diversity

Apart from the troubled reasoning, there are also plain flaws here.
Mutations introduce genetic INNOVATION. Hence, mutations bring DIFFERENT combinations of alleles than those produced my mere recombinations in Mendelian processes.
As demonstrated in the experiments by Lenski and the ones on beetles, yeast and other sexually reproducing eukaryotes.

The problem here is not disabled genes being called junk DNA but junk DNA supposedly only consisting of pseudogenes.Please answer points made by several persons here on the observation that the vast majority of junk DNA is NOT disabled genes and discuss it in line with your claims.

You mean genotypic frequency rather than gene frequency. Gene frequency is often used interchangeably with allele frequency, however, this is not really correct. Genes don't change frequency; genotypes and alleles are what change frequency. Yes, a particular allele can become fixed in a subpopulation so that all individuals become homozygous for that allele. And yes, the phenotype could be significantly different in the subpopulation, but "genetic substrate?" What could that mean? You put "selection" in quotations (I am not sure why), but no, it is not a selection event. Selection would change allele frequency; recombination only shuffles alleles around. You need more than just shuffling alleles around to create reproductive isolation. Think about it... those combinations would have existed in the original population, even if one subpopulation were completely homozygous for one allele and the other were completely homozygous for the other allele, when they recombine, it would just result in the formation of heterozygotes again. The problem with these genetic bottlenecks is that fitness is greatly reduced and there is not enough genetic diversity to contribute to improving fitness. Therefore, the population cannot respond to increased pressure and they struggle to survive. This is selection and and how inbreeding depression can cause the extinction of a species. Natural selection has some of the strongest empirical support of any of the tenets of evolution. It has been studied extensively, its hardly an assumption anymore. True, he didn't have genetic evidence and most of what he thought about heredity was flat out wrong. Migration is part of the ToE and would certainly contribute to changing allele frequency. One way conservationists introduce genetic variation into inbred populations is to introduce individuals from a distinct population. There has been tons of work done on these issues. There is much more evidence now than Darwin had. You should be able to examine the literature and find examples that you can critique and show that the evidence supports your hypothesis better than the hypothesis the authors propose. Some examples have already been presented, I could give you some others.Despite your accusation that researchers are just trying to toe the party line, it is just not true. Some things are so firmly established they just no longer need to continue being argued. However, there are still some very contentious aspects in evolutionary theory.So, to bring this back around to the topic... speciation has been extensively studied in evolutionary biology - it is the central topic of evolution after all. You should be able to find examples of speciation that demonstrate that a reduction in genetic diversity is required. I can present you some papers that discuss speciation if you wish...HBD

Yep, that is on my list for another post on the Silly Design thread. Certainly more like an artist than an engineer ...Enjoy

Google "gene frequencies" HBD. I've used the term correctly and usually write it "gene/allele frequencies." I don't mean to accuse scientists of consciously "toeing the party line," just being true to their paradigm and working within it. It's the natural sensible thing to do, but it does mean they will automatically exclude any slight hints in the other direction, as simply Wrong. What else?I'm skipping around and responding to things that catch my eye, so if I'm missing things I hope I can come back. Another day of headache from eyestrain at least.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

See the Wikipedia article "Speciation." They do mention mutations, of course, along with the other factors involved in changing the genetic picture from population to population, and in fact the mention of mutations sounds hypothetical, the usual obligatory assumption, rather than known for sure; and they don't even suggest which of those factors has the most effect. The impression they leave with me is that the population split itself can change the genome sufficiently to prevent interbreeding. Also as I recall, ring species may be able to interbreed among themselves except at the extremes, the first and the last populations. Why would mutations suddenly make that difference? The main thing that's been going on around the ring is the formation of new populations from fewer numbers out of the previous ones and the consequent decrease in genetic diversity from population to population.Edited by Faith, : No reason given.

Since you made this ruling I've been avoiding those terms, but imagine my surprise when I was looking at Jerry Coyne's book this morning over breakfast ("Why Evolution Is True") and found that his section on pseudogenes etc. is titled "Dead Genes."

Wikipedia is not meant for providing extensive scientific elaborations. It is just an online encyclopaedic.But I (and others here) have been providing you several studies where the genetic mechanisms are spelt out. For instance, my contributions, the Lenski experiment, experiments on beetles and yeast (sexually reproducing, eukaryote multicellular life) as well as Dachshunds.Now how long will it take before you going to start to address those instead of pussyfooting around?I also note that NONE of my MANY questions were addressed, let alone answered satisfactory.Are we in a DEBATE here or not?

I'm probably never going to get to them at this rate. I can't spend that much time on detailed studies like those.What questions I haven't addressed I have no idea. I know I did address many and you still complained that I hadn't so at some point I couldn't care less.Edited by Faith, : No reason given.

Your post is not a response to my point. Do you understand that you have reach your "impression" simply by rejecting what the reference actually says? As for the idea you are justified in doing so because of a perceived lack of evidence or clarity, that's also hog wash. You (Faith) picked the particular statement. If the statement did not contain the required evidence or clarity, that's your own fault.Besides that, you've missed an important point.The cited reference is talking about a mere population split. Well a population split does not require any genetic change at all. It merely simply requires some form of isolation. Isolation can come from external factors such as a hawk picking off all of the white mice in an area, or peahens just not like a particular pattern on a peacock's tail, or one animal being to timid to approach a larger female. Isolation through inability to interbreed is just one possibility. It also happens to be something you've claimed can happen just by selecting allele's which is why I am discussing it. Your reference is correct, but it is not on point.In any event, the short answer to your post is that you've simply switched from talking about genetic incompatibility and trying to explain how that can come from mixing combinations of allele's and lumped that into remarks that apply to mere isolation. Sorry, but that just won't work. I answered that question in my previous post. I explained how mutations could cause things that could not be achieved by mere Mendelian reshuffling of allele's. I gave supporting examples as well. The short answer is that mutations are not limited to merely adding a new allele to a gene, and that makes all of the difference.

It would be an extremely rare population split that did not. You aren't thinking. Population splits bring about changed gene frequencies in at least one of the resultant subpopulations and often both, and those changes are KNOWN to bring about new phenotypes (due to reduced genetic diversity according to my argument but that's not usually included in the standard discussions). Isolation isn't going to make a difference if there is no difference in gene frequencies. It's the new mix of alleles in new combinations that makes the difference. Isolation is necessary of course because gene flow mitigates or prevents the change in gene frequencies. ABE: You are not talking about isolation, you are talking about selection. Migration is a form of random selection. Isolation requires that there be no continuing gene flow between populations so that the selection affects the phenotypes brought about by the reduced genetic diversity caused by the selection as it is inbred in the new population). You seem to be confusing so much terminology here I'm not sure how to answer. /ABE Reproductive solation is necessary for bringing about the new combinations of alleles due to changed gene frequencies that bring about new traits in a new subpopulation. Even partial reproductive isolation can bring about changes but complete isolation makes the effect clearer. I AM talking about the effect of genetic recombinations. Sorry, you aren't getting the point here. MY point was you don't know if the mutations have occurred or have anything to do with the effect. I rather suspect the low frequency of such mutations precludes them having much effect anyway. But sure they COULD have if they DO occur. But when I mentioned the failure to interbreed occurring at the extremes of a series of population splits, that was a direct challenge to the idea that mutations would be the cause, because there is no reason why they would affect only the extremes where it's the normal recombinations that would have the major effect. 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.

Note that I did say that gene frequency and allele frequency are often used interchangeably. But you are either using it improperly or the paragraph I was responding to makes absolutely no sense. Inbreeding doesn't change the proportion of alleles but it does change the "gene/allele frequencies" ??? How does that make sense?So let me rephrase my comment about inbreeding...Inbreeding does not change the gene/allele frequencies what it does is change the genotypic frequencies.It takes selection or drift to change gene/allele frequencies.HBD

We seem to be having a semantic weirdness of some sort. Let me see if by rewording what I said it can be resolved."Inbreeding doesn't change the proportion of alleles," that's the result of the population split which brought about the new frequencies of alleles, "but it can mix a new set of gene frequencies in ways that appreciably change a subpopulation" which DOESN'T mean it "changes the gene/allele frequencies" which is how you are reading it. Those frequencies were changed by the population split itself though the result in a new look to the population doesn't show up until after some generations of working them through the population by inbreeding. What inbreeding does is mix them, recombine them over the succeeding generations. Same proportions that the population split caused, though even this COULD change too, such as by genetic drift, but when the split occurred the individuals possessed whatever alleles they'd possessed in the former population, so they'd look like other members of that first population. But as this new subpopulation with its new set of frequencies inbreeds over the next how-ever-many generations, new phenotypes will start to appear from the new proportions. What was characteristic of the original population may now have fewer alleles and give way to more alleles for a different characteristic, and across many different traits at the same time. It takes the recombinations through inbreeding to bring them out and begin to show differences in traits from the original population. If this daughter population continues to inbreed in isolation, its set of frequencies will keep getting recombined until eventually I'd expect a whole new subspecies with a whole new look from the original population to emerge. Yes, migration is the selection in the situations I'm talking about, a population split in which the two subpopulations become geographically isolated from each other, a random sorting of individuals that form their own isolated inbreeding population. This is selection. It's like genetic drift except that it physically separates from the mother population while drift forms within it. Both form by reproductively isolating a subset of alleles from the mother population, and over time this will produce new phenotypes in either situation. This doesn't make sense to me. I don't know what you mean. What I'm saying is that individuals will now begin to emerge that have new combinations of alleles for various traits than were present in the original population, at least more of some, less of others, and new possible recombinations as a result of the new proportions, and this will eventually change the look of the whole population after many generations of inbreeding. This MIGHT be what you are saying but I'm not sure.Edited by Faith, : No reason given.

Consider this example: trochiloides is the ancestral species. Now imagine there are 10 mutations between trochiloides and ludlowi - not enough to cause infertility. There is also 10 mutations between trochiloides and obscuratus so they are able to hybridize freely as well. Also 10 mutations between ludlowi and viridanus and between obscuratus and plumbeitarsus, all able to freely hybridize.However, between viridanus and plumbeitarsus there are 40 total accumulated mutations. So, now the species on the extremes of the ring have significant differences and no longer can interbreed.If all you are doing is shuffling alleles around in different combinations, there is no basis for genetic incompatibility. If all the alleles existed in the original population and are simply being shuffled into new combinations, then all those alleles would be compatible because they would have all "seen" each other at one time in the original population. Arranging them in different combinations wouldn't result in incompatibility. Yes, what NoNukes was describing in your quote is more like selection. No. There are four primary evolutionary forces. Migration, Selection, Mutation, and Drift. Selection depends on fitness differentials, migration does not. ???? HBD

I'll argue it if you like but it ought to be obvious that migration is a form of RANDOM selection, not purposeful selection like natural selection, because it randomly creates a new set of alleles that comes to form a new subpopulation, which is also what natural selection does, and domestic breeding. Genetic drift is also random selection and isolation of a subset of alleles, not purposeful. I'm aware of the four evolutionary definitions but I don't agree with them. For one thing "Migration, Selection and Drift" all have the same basic effect in "selecting" a new set of alleles that result in a new subpopulation, and Mutation doesn't belong in the list at all because it's an additive process like hybridization and other forms of resumed gene flow. "Fitness" is one of those tenets of the ToE that really doesn't mean anything: it's rarely the cause of a genetic change. Pocket mice and peppered moths are very rare examples that more or less fit the definition, but I'm arguing that most microevolutionary changes are the result of random reshufflings of alleles as in migration. I'm glad all these things are finally being noticed because I've used this terminology for years and although I'd carefully define it all from time to time it was never really noticed.ABE: I also object to that breakdown of the supposed different routes to Speciation on the Wikipedia page of that title. All those routes are basically the same route with the same genetic and phenothypic outcome, the distinctions are artificial and ultimately meaningless.Edited by Faith, : No reason given.