Evolution Requires Reduction in Genetic Diversity

Diversity within populations that are fairly stable, meaning they aren't actively evolving, doesn't have anything to do with my argument; it's only when they diverge that the phenomena I'm talking about occur. The higher the original genetic diversity the better for their health of course, and assuming relatively large daughter populations -- that is, no extremely small population splitting off, the longer it would take for the scenario I have in mind to play out. If Founder Effect does occur out of a very large and diverse population then of course you'll see dramatic new phenotypes along with drastically reduced genetic diversity in the daughter population. I assume you wouldn't disagree with any of this, I just want to be sure it's clear. First, when you use the unmodified term "diversity" I have to wonder if you still have GENETIC diversity in mind. In this case it's pretty clear you mean phenotypic diversity. There will certainly be an increase in PHENOTYPIC diversity when populations split: this is, after all, basic (micro)evolution. And if that's what you are talking about we have no argument and in fact it's what my argument is explaining: how in a smaller daughter population the emergence of new phenotypes will be accompanied by a reduction in GENETIC diversity: the high frequency alleles bring out the new traits, while very low frequency alleles, many for traits in the original population where they are/were high frequency, give way to the higher frequency alleles and may eventually get eliminated from the population altogether.Diversity in a large well established, OLD, stable population, which can be the basis of the divergence you are talking about, is rarely phenotypic, the individuals usually having basically the same appearance, while genetically they may have a very high diversity. I sometimes wonder what those great herds of very homogeneous-looking bison would look like if a small population of them was isolated for some generations. Perhaps you know, but I've only seen the look of the large herds. A population of a million black wildebeests shows hardly any phenotypic diversity at all, like the bison, but if a smallish (could be hundreds, who knows) daughter population gets isolated from it and breeds only among themselves for however many generations it takes, you are very likely to see the emergence of a pattern of new traits you had no idea was in the genetic makeup of the wildebeest population, and eventually get a completely different kind of wildebeest. Which may be how the blue wildebeest formed from the black.Are we in agreement here? That's a pretty good statement of the argument and I usually conclude my argument with some such statement, not sure how that fails to get across.But I realized recently that MICROevolution doesn't need an increase in genetic diversity: If it starts from a fairly large genetically variable population it won't run out of genetic diversity for quite some time; what needs the increase is macroevolution, or the ToE itself, because as I work it out, it is at or near the point of "speciation" that microevolution comes to its natural end, when that line of microevolution has run out of genetic diversity, so that no further evolution, which would of course be MACROevolution, can possibly occur. Well, here again you are clearly talking about phenotypic diversity, having switched from your initial reference to "genetic diversity." Yes, the daughter population becomes phenotypically different from the parent population. This is, of course, basic evolution (microevolution). THIS diversity MUST increase, but while it is increasing GENETIC diversity would be decreasing. I've done my best to make this as clear as possible post after post, thread after thread, year after year, but it still doesn't always get across. Again you are talking about PHENOTYPIC diversity about which there is no argument. It's HOW you get that phenotypic diversity which is the substance of my argument, which is that it requires A REDUCTION IN GENETIC DIVERSITY.In the new allele frequencies that occur with a population split, there is usually an increase in some alleles from low frequency to high frequency which can confuse things, because my emphasis is on the fact that that increase depends on the reduction of other alleles for the same traits. As in domestic breeding: you get the new traits by favoring some alleles over others, and the others must decrease or in purebreds completely disappear from the breeding population.The reduction in genetic diversity may not show up much at first, especially in a relatively large daughter population, but my claim is that it is always the trend in developing new traits, though it will be in the smaller daughter populations where it will be more apparent.

	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

I like the idea of trying to pin this down and I started to write out some thoughts about the table. But I realized I need more clarification at the outset.For instance, why "within SUBpopulation?" What subpopulation? When did the population split occur? Shouldn't it be just "population" or parent population? And the "between subpopulations" then should be "between parent and daughter?" At least I don't know what is meant here as presented.Also, again this chart is not about genetic diversity, it's about phenotypic diversity.I have a feeling I'm going to need to spell out how I read each of these categories in any case; I can't just answer yes or no to what the chart has until I know exactly what the terminology refers to.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.

Sure, like your answer on the Lenski experiment (that is,NO ANSWER).
Or your answer on the experiments on sexually reproducing species (that is, NO ANSWER).
Or your answer on how the number of alleles in extant human populations are observed to be larger than the maximum of 4 alleles in Adam and Eve (that is, NO ANSWER).Etc. etc. etc. etc. etc.You did answer all the points about mutations many times over?????NOT THAT I NOTICED.
For the second time: SHOW ME WHERE.As I said before: don't LIE Faith.Percy: when a person lies to me I will call that lying.
It is what it is.Edited by Denisova, : No reason given.

I understand that, but we need to establish what we are talking about when we say genetic diversity. Let's use the terminology "genetic differences" for the time being. Genetic difference, genetic variation and genetic diversity mean essentially the same thing, just have subtle differences in their usage. I think that using genetic differences will much clearer for the purposes of this discussion. Nope. I am referring to genetic diversity (that is genetic differences) throughout. Maybe because the title of the thread is "Evolution Requires Reduction in Genetic Diversity."I would like to focus on some of these basic principles before we discuss your specific scenario. Not only will it ensure that we are talking about the same thing, but it should also help you understand your own argument better so that you can better express it. (although I will compliment you that you have done a much better job of clarifying what you are trying to get across in the last couple messages, at least with me). I also suggest that there is no need to specify "micro" or "macro" evolution. We will be talking about only one issue... how populations diverge and become distinct enough that we recognize them as different species or subspecies. The diagram below should help clarify what the table is referring to At this point, both subpopulation 'A' and subpopulation 'B' are the same species but live in distinct geographical regions. They are both part of the same metapopulation. Now look at the table again. I made a couple changes so that it relates to the diagram above.

	differences within 'A'	differences between 'A' and 'B'	Affect all loci
Mutation	increase	increase	No
Migration	increase	decrease	Yes
Drift	decrease	increase	Yes
Selection	increase/decrease	increase/decrease	No

Now, what we are trying to understand is how subpopulation 'B' becomes different enough from population 'A' so that we can recognize it as a distinct species or subspecies.If your argument is truly that there is more genetic difference between individuals within 'species A' than there is between individuals in 'species A' compared to individuals in 'species B' (assuming that they have somehow become distinct enough that we recognize them as separate species or subspecies); then that not only seems to go against basic logic but against every observation ever made about different species. Perhaps your argument is that the genetic differences that increase between populations are irrelevant and when only the relevant genetic differences are considered, the diversity decreases.But we can address all that later. First let's come to an understanding as to how population geneticists view this issue and then we can talk about what is wrong about that view and how your idea better fits the observations.ABE:Nope. It's about genetic differences. That would be fine. We can talk about each process separately and I can provided experimental observations to explain.
/ABEHBDEdited by herebedragons, : No reason given.

From the Forum Guidelines:

10. The sincerely held beliefs of other members deserve your respect. Please keep discussion civil. Argue the position, not the person.

Debate can be nuanced and complex, consisting of far more than just facts and arguments. If your goal is an admission of error then it is not enough to simply bombard your opponent with facts and arguments. You must coordinate your resources into a strategy that brings about in your opponent an admission of error, something Faith has done many times, including in this very thread.It is often observed that scientists with the best minds are the hardest to persuade to change their minds because they are so knowledgeable, and so skilled at marshaling that knowledge into a defense of their current position and an attack on the new position. It is also observed that new paradigms are rarely adopted by the old guard but only gradually become accepted as the old guard dies off. Changes of mind are rare, and admissions of changes of mind are even more rare.So use your facts and arguments to maneuver Faith into admissions of error. It's a much bigger challenge than merely demonstrating to yourself and those who already agree with you that you're right.

This is not an accurate statement of your position. Your position requires that it be impossible to gain diversity in a non-evolving population. For example, in addressing the lunar Russian example you claimed, without any argument just assertion, that when the lunar russians returned, all new mutation generated diversity that occurred on the moon would be lost upon reintegration.There is no question that at the time of reintegration there is new diversity. But you have claimed that the non-diverged population will lose diversity gained from mutations.Or let's make it short and sweet. If you are not claiming anything about non diverging populations, then you lose the argument. Because non isolated populations can gain diversity from mutations even without selection.Once selection occurs, and it would not occur upon every mutation, even if there is some some attendant loss of diversity, if that is the case, diversity need not fall below that which existed at the time the original population first formed. So there need not be a net loss of diversity. Wrong. Mutation always involves genetic diversity and your chart includes mutations.

First of all I didn't argue the person as such but her conduct, that's different. I didn't call her a liar but I wrote I don't like to be lied to. My goal is not an admission of error as such but I was challenging her position and ASKED her to back it up and also to just answer dozens of more substantial questions.
She just won't. Just like that.She also dictates the terms of debate: if Faith does not want to address E. coli experiments, it won't happen then. If she decides that there is no evidence, as she did on several occasions, you van provide her tons of evidence - it just will be evaded. She even then writes "I addressed this on several occasions". So now and then it is getting surrealistic. Basically she just excludes everything that she can't address and that threatens her positions, thus narrowing the topic in a way she can go on for another two years to mock about people not understanding her.I already asked you twice if it's normal here in this forum just to evade and dodge.
You encouraged Faith to engage the debate and the points put forward.
Well she didn't.

Oh nooooo. Things are MUCH worse than I thought.If you think ... we are a million miles from communicating on this subject. Not for me it won't. To me the differences between these terms are not at all subtle, but I'll need time to pick myself up off the floor and dust myself off before I'll have any idea where to begin to respond.But then you knocked me out completely with this one: If you actually think you are talking about what I mean by genetic diversity the disconnect between us is HUGE.I'm too stunned to think right now.I was already thinking of taking this to a Great Debate between the two of us because the other discussions on the thread are driving me crazy in different ways, and at least you are focusing on issues that are closer to what I'm trying to say. But now I don't know what to think. Maybe I'll have a better idea later.Sorry not getting to the rest of your post. I have to recover first.

This would be where you would quote reputable sources that define genetic diversity, genetic variation and genetic differences and explain why you think they are too different to use genetic differences at this time for the purposes of this discussion. I could define them for you and explain why we don't need to distinguish between them at this time. But it would be better if you provide your definition. Yes, I would expect the disconnect IS huge, that is why we are having a debate.There are differences between those terms, but for the purpose of this discussion we don't need to be concerned with them at this point. First you tell me what you think the differences are and then I will respond in kind. A Great Debate would be fine with me, it would allow us to have a tighter focus of issues.Part of the issue here is we need to put this in terms that we can actually measure. If we are talking about some idea of genetic diversity that cannot be measured or demonstrated, then we will get no where but speculation. But if we look at the parts we can measure, we can then apply those principles to the bigger issue.HBD

Curiously I've been on this forum for a little over 10 (yikes) years, and Faith has been here longer ... nothing really changes.What you come to realize (if you don't leave in frustration) is that Faith provides a sounding board that allows us to discuss specific points in detail, whether is is the geology of the Grand Canyon or the genetic basis of evolution.And you come to realize that the point of the debate is not to convince Faith, but to lay out a cogent argument bolstered by empirical evidence so that people lurking can follow -- they are your true audience.Personally I enjoy learning new things from others from their responses.Enjoy

^^^^^^^^^^^^^^^^^^THIS (I'm typically the guy learning as evidence repeatedly beats Faith).Edited by ThinAirDesigns, : No reason given.

The Wikipedia definition of Genetic Diversity is how I've been using the term, and as I already said MANY TIMES it's quite measurable. Heterozygosity for instance, AS I'VE SAID MANY TIMES, is synonymous with genetic diversity and it's measurable. This and Alleles per Locus, WHICH I'VE ALSO MANY TIMES IDENTIFIED AS A MEASURE, both of which, I"VE SAID MANY TIMES, I would be looking for in my laboratory experiment, are both listed in that article as measures of genetic diversity.I see no need for any other term.Genetic differences between populations or individuals is not relevant to my argument, which is about how genetic diversity must decrease as new phenotypes emerge. And my focus is always on one particular line of microevolution, comparing it only with the immediate parent population. This line of phenotypic variation may be brought about by selection but more often by the "random selection" of a population split. (I've often encountered mention of a dispute about selection versus "neutral" causes of evolution or phenotypic variation: I'm with the "neutral" camp.)I think by proposing another term for my argument you've mainly succeeded in wasting time and creating confusion.By the way, the only way I might want to reword my argument would be something like:Evolution, the emergence of new phenotypes in a subpopulation, requires reduction in genetic diversity.ABE: Do you have a problem with my understanding of genetic drift as just a version of microevolution brought about by random factors just as it is brought about whenever a daughter population is formed? That is, it is a daughter population that happens to form within the parent population rather than by separating from it.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.

It is possible for you to define genetic diversity in such a way that nobody cares about the term because your definition is irrelevant.Just as an example, if we use the definition of alleles per locus, and ignore the generation of completely new genes, then a loss of diversity under your definition would not prevent more genetic variety which would in turn allow more generation of species.Common descent requires that all of the traits in every animal have developed from some extremely simply life forms that had no wings, ears, eyes, lungs, toe jam, etc. Evolution is not just about whether humans have more or fewer variations on eye color than did the chimpanzee like ancestor from which they developed. The generation of completely new traits and functions is required.
Under your definition, mutations that provide new genes or new loci don't count as adding diversity. That's folly in my opinion.Edited by NoNukes, : No reason given.

You’ve claimed you are talking only of GENETIC diversity in this post so I will reconsider it. When you say it must then BECOME different, this to me implies phenotypic change. But since you say you are talking about genetic diversity, the only way this is true is that It will have different allele frequencies, that’s THE genetic difference, and as those new frequencies recombine over subsequent generations of reproduction in isolation. THEN you’ll see the emergence of the new traits based on those alleles. If you are saying only that the new allele frequencies constitute the genetic change, that’s true enough but also not the way one would usually describe it. So again, although you may not be talking about the phenotype, it’s hard to see how you are talking about genetic diversity either. Phenotypically, yes, of course, but I can’t see how this relates to genetic diversity since all that’s happened genetically is the new set of allekle frequencies, there is no increase in genetic diversity. Again, the only way this is true is if you are talking about the new phenotypes that emerge from the new set of allele frequencies, and I fail to see any relevance to the question of how much. It’s begun to dawn on me that you are speaking so exclusively from within the conventional ToE-based paradigm that I can barely follow you. Certainly you do not have my argument in mind though I had thought earlier you were clearer about it than this. OK, since you’ve said you are only talking about genetic diversity I’ll see if I can respond to the table from that point of view and I do have in mind the diagram of the two subpopulations and metapopulation.

	differences within 'A'	differences between 'A' and 'B'	Affect all loci
Mutation	increase	increase	No
Migration	increase	decrease	Yes
Drift	decrease	increase	Yes
Selection	increase/decrease	increase/decrease	No

Yes a mutation within a population would be a genetic increase. And also an increase in relation to another subpopulation that doesn’t have a mutation.But there’s still something odd about this I’m not getting. Apparently A and B are not related parent-daughter? Just two populations that formed out of the metapopulation?It’s hard to think about Migration within a population since it involves the merging of two populations. If that is what is meant then of course there is a genetic increase. But in relation to B there’s a decrease? Is that because the migration came from B? This is not at all clear on the table.As I’ve said I think of drift as a population split within a population with allele frequencies different from the parent population. And I’m completely unable to see how it relates to population B.Also not making sense of Selection. Guess you’ll need to do some more explaining. See above. Very little of it makes any sense at all. Yes, in a population split all the loci are affected by the new allele frequencies. But the table doesn’t illuminate anything for me in that regard. Edited by Faith, : add table

So, apparently B IS a daughter population to A as the parent? That is not clear at all in the diagram or anything else you've said.Daughter population's different allele frequencies give it an entirely different overall appearance after sufficient generations of breeding among its individuals. Since B is quite small by comparison with A this shouldn't take a very long time. I can't make ANY sense out of this paragraph. I don't like your term "differences" and don't think it says what genetic diversity says. What I say is that There are more allelic possibilities in A than in B, that's the difference in genetic diversity . [With a larger daughter population the differences might not be so large, but with this small B population I think it can be said with some certainty that there is a clear difference in allelic possibilities between the two populations.] But B may make some dramatic phenotypes out of its smaller allelic collection.And again, "the genetic differences that increase between populations" such as by mutation or migration etc., get reduced by the "random selection" or selection or subtractive processes of the population split that brings about the (micro)evolution. I really thought you had more of an understanding of my argument than this. That makes me want to laugh at this point. It would be nice if we could establish ANY communication about ANYTHING.

Interesting you say that in response to the definition at Wikipedia. How often do mutations generate new genes? It's unlikely they even generate viable new alleles. But as usual you aren't getting it: it doesn't matter where the genetic material comes from, when it undergoes the processes of microevolution the gene pool will lose genetic diversity. If mutations should happen to be in the new subspecies, they may end up in a population that undergoes speciation, but if I'm right that such a population is genetically depleted all you have then is a population that can't interbreed with others of its kind, and has no ability to evolve further, but has some traits it owes to mutation. No, they do add diversity, or would if they actually make viable alleles, which I doubt, but they would only make alleles for the existing genes for those little insignificant traits, hardly ever if at all an actual new gene. So all you are getting is new variations on those inconsequential traits, you are NOT getting the "completely new ttraits and functions" evolution requires. That's all a figment of the evolutionist imagination. In reality microevolution comes to a natural genetic dead end, with or without mutations.