MACROevolution vs MICROevolution - what is it?

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Sorry, the word "selection" doesn't have to mean it has a purpose,

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I didn't assume a purpose. But there must be some causal reason why those individuals were selected relating to the features in question. And there is not.

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it is certainly random selection when a particular small number of individuals is reproductively isolated,

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That is drift, not selection.

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If you make a pile of small objects and take a random handful out of the pile to put to use, you've selected that handful in the sense I'm using the term

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Unfortunately for you, you were responding to my use of the term, and I was using it correctly. And if you had thought about it you would understand that actual selection for the new features was required after the lizards arrival.

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You might withhold your insults until you understand the situation.

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You might learn to stop equating criticism with insult. And since I did and do understand the situation you have no point here at all.

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No there doesn't have to be any causal reason, it was purely random

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If it is purely random it is drift, not selection - at least by the way everyone else uses the terms. For reasons that should be obvious - it is not a difficult concept. And the founder effect is obviously inadequate when none of the founders have the traits in question.And you need selection to explain why the lizards changed in such a short time.So let me repeat. I was not using your private definition of selection and drift is inadequate - especially the founder effect. If you actually tried thinking about it you would realise this.

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Drift occurs within a population as I understand it, and I've never seen the formation of a daughter population called drift.

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I have certainly seen the relevant aspect - the Founder effect - called drift. And since it is random, why should it be called selection rather than drift ?

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The selection needed to explain the rapid change is in the original small number of founders.

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Try thinking about it. Explain how it could be that none of the founders could have the traits while all of the current population do, without a change in allele frequencies.
It just isn't possible (unless it is an environmental response after all)

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The same way Darwin's pigeons did not have the traits they came to have after his assiduous selection program.

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If you think that selectively breeding from birds with the traits is the same as randomly breeding from a small starting population you have a problem.

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"Without a change in allele frequencies?" You are really not getting this

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On the contrary. You see, I have actually thought about it.

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The founding population has the different allele frequencies from their parent population.

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And none of them have the traits in question. Whether you forget that or fail to see the significance is unimportant. But it is very important.

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It is those new allele frequencies that bring out the larger head and jaws over a number of generations of sexual recombination among those new allele frequencies. It is you who aren't thinking.

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Assuming that things must be the way you want them to be isn't real thinking.Are we really to believe that the vast majority of gene combinations taken from the original founders have the new traits ? That it was just by chance that none of the founders had those traits ? It's absurd. And it is the only way you could be right.Consider the example of a recessive allele. Even if you picked a founder population who all had one copy of that allele you would still only have a frequency of 50%. For the trait associated with that allele to take over the population that allele would have to increase in frequency to 100%.If you want to say that things can work out the way you want you are going to have to explain how it can be possible. No vague statements about "recombination" somehow doing it (especially as it obviously isn't enough). An actual explanation.

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Yes I do think the same kind of result can come about through either Darwin's selection or the random combination of genetic material in a randomly assembled founding population, though it would no doubt take longer in the random scenario to get all the relevant genetic material into the mix

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In reality it is very unlikely. You would need drift or selection to get even one really distinctive variety.

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It all depends on what genes were present in that founding population and nobody knows but it can be inferred from the results that whatever increases head and jaw size was present and dominant and would be increased over generations of recombination.

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The fact that it was not seen in any of the founding population shows that it was certainly not dominant - and any significant increase would require significant increases in the relevant alleles.

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If you don't see that the small founding number is already a new set of gene frequencies that will determine the development of the lizard population, you really have NOT thought about it enough despite your declarations.

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A new set of frequencies, yes. But sufficient to produce what is seen without it being obvious in the founding population, certainly not.

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I would expect it to emerge over a number of generations, not be a matter of "vast majority" but something that gets increased over timE

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You misunderstand. The number of possible combinations - which is what I am speaking of - cannot increase unless new alleles are introduced.

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That's how I think of Darwin's pigeons. He'd pick a pigeon with a very slightly larger breast perhaps and breed for that characteristic, finding that all it takes to increase it is repeating matings of the birds that have that characteristic. I don't see why this couldn't happen randomly.

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That is selection or drift changing the frequency of alleles. You claim that it can happen without either.

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We're not talking about "new traits," all it takes is ordinary sexual recombination of a new set of gene frequencies to bring out hitherto unexpressed traits over a number of generations.

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Please can you not waste time with pointless semantic arguments which change nothing. Whether we call the traits new or not I am not considering mutations at all at this point.

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There's a lot of stuff potential in the genome of any animal that doesn't get expressed except under special circumstances, including random selection of a small founding population, especially effects that increase over generations like the exaggerated pigeon breasts or the exaggerated lizard heads. You get quite noticeable differences from population to population in a ring species and there's no reason to assume anything other than inbreeding of changed gene frequencies to explain it.

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All of which IS due to changing allele frequencies. Which you claim is not required.

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However, it is possible that the founding population did contain a lizard or two or three that had a slightly larger head than the others, but not enough to be noticed. Surely Darwin's original pigeon breast was hardly noticeable. If the trait in question is governed by more than one gene, which is the case with most traits after all, then increasing it over generations isn't a big mystery

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You fail to understand the issue. The question is not how a bigger head appeared in one or two lizards, the question is how did it come to be that all of the present population have bigger heads - and the other features that distinguish them from the parent population. I say that - unless it is an environmental response - to do it in the time available requires rapid selection. You insist that somehow it can occur without any change in allele frequencies from the founder population. And accuse me of "not thinking" about it when I disagree.

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Well, in my scenario all genes originally had only two alleles, and that's my default assumption, so each individual of the founder population should have had at least one copy of the recessive allele

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I hope that you can see that that is unlikely.

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Following normal Mendelian genetics that allele should frequently be homozygous in subsequent generations.

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Where "frequently" is only about one quarter of the population, even with the very favourable assumption that all the adults had a copy of the allele. A quarter is rather less than all.And if we have any more than one gene to think about the proportion with the full set of new traits will be much smaller than a quarter.

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But there are probably many genes that affect head and jaw size so with such small founding numbers we should be getting homozygosity at many of those loci in a few generations, increasing the effect.

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With many genes the situation is hopeless. If we assume that it is all due to recessive genes the proportion of the population with the full set of traits goes down to one sixteenth with two genes, one in 64 with three, one in 256 with four. Unless you have major changes in allele frequencies - which you claim are not necessary - it is obviously hopeless.

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Believe it or not I'm just pursuing what looks to me like the evidence, none of this has anything to do with "what I want" so you can stop with the incessant insults.

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What evidence lead you to believe that no changes in allele frequency - relative to the founding population - were required to explain the changes in the lizards ? What evidence lead you to claim that I hadn't thought about the matter ? If you had anything to support your claim why haven't you produced it ?And calling criticisms insults is just a lie. Especially when the evidence clearly supports those criticisms.

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You don't need additional selection if the original founding gene frequencies have clear highs and lows, which is likely to be the case among such a small number of individuals. Extreme lows will become lower and drop out over time, while the highs come to dominate.

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Which would still be a change of allele frequencies through drift. And too slow for this case. And come to that we still have the problem that the traits in question are not seen in the founders, and don't seem to be known in the population at large.

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I don't need your abusive attitude.

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All you are getting is push-back against your arrogance - criticism you invite with your attitude. If you bothered to think things through - if you bothered to actually get things right instead of proclaiming that you are right without understanding and blaming those who disagree with you, you might get a response more to your liking,Justified criticism is neither insult nor abuse. If you are insulted by what you really are, and what you are really doing the answer is to do better.

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I'll say it again. If Darwin could get traits from a founding pair of pigeons that didn't exist in either one of them, the lizards could also produce such a new trait just from previously unexpressed combinations of existing genes.

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Then I'll just point out again that selection was needed, and it is certainly needed to have a rare trait take over the population in a few decades. And we aren't talking about just one trait

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Fine, add drift, but drift is a form of selection and it can happen just as rapidly as what I'm talking about from one generation to the next.

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Drift is not a form of selection and it is slow because it is not selection.

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Your attitude is abusive

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And that's a lie.

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and all I've been doing is pursuing my thoughts about these things so you have no excuse.

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And that's not true. After all it is quite clear now that i was correct to point out that further changes in allele frequency would be needed and your assertion that I hadn't thought about the matter was false and baseless. You are only thinking about the matter now - to the extent you are - because I pointed out the obvious problems that you hadn't considered.If you don't like being criticised then you could at least try not to deserve it.

Of course the claim that evolution has a built-in stopping point has already been disproven.

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Evolution is not a straight linear one-foot-after-the-other process because in order to get new varieties or races or breeds or species the genetic material for other varieties must be reduced, and completely lost in some cases.

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The point you are supposedly refuting is the idea that smaller within-species changes can add up to eventually produce a new species. Your assertion here hardly seems to work.The Pod Mcaru lizards don't really help for this either. Not unless you want to argue that their changes are the product of a macroevolutionary process distinct from microevolution (as the terms are used in science) - and I certainly don't think you'd want to do that.

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I brought this up because the necessary genetic loss is never acknowledged in discussions of evolution

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Which is sort of a funny claim when we are talking about a program described in Dawkin's The Blind Watchmaker - a book that makes it quite clear that the culling of variety by natural selection is an essential part of evolution - and even more so when we consider that the program is often attacked by creationists for being too effective in culling the less desirable variations.

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...and the computer simulation models perpetuate the same wrong idea of an unimpeded series of changes from microevolution to macroevolution.

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Except that there is no such distinction in the program (which is a demonstration of cumulative selection not a simulation of evolution anyway - quite explicitly stated in the book.

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Apparently even when they take "selection" into account they fail to represent this fact.

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By which you mean that the program makes the "mistake" of illustrating a major hole in your argument. So long as there is a source of new variations evolution will not come to an end by running out of variety. Which, of course, is no mistake at all. Nobody is required to pretend that you are right.

That's a misrepresentation. Jerry. Coyne certainly accepts that what he would probably term species complexes exist. So far as I can tell he doesn't like to call them ring species because he thinks it is an over-simplified view and that geographic distance isn't a very important factor in their formation.

You do realise that that quote supports my point ? That he's only denying that the examples fit the "classic sense" of ring species ?And if you didn't know that "species complex" is the more correct term I don't think you are in any position to judge exactly what Coyne means.And you obviously hadn't bothered to read the whole article where he explains his objection to the common example of the Ensatina salamanders: Edited by PaulK, : No reason given.

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But the implication of the genetic loss by selection is overlooked, as if you could cull indefinitely and not deplete genetic diversity.

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But of course you can cull indefinitely so long as you have new variations arriving.There's no implication being ignored. You're just very obviously wrong.

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First, they don't keep arriving, even according to establishment descriptions of how mutations occur; beneficial mutations are extremely rare.

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That's a major non-sequitur. The frequency has nothing to do with whether they keep coming. Mutations will keep coming and a small proportion will be be beneficial. But neutral mutations will do - or even mildly detrimental mutations - any variation that could become beneficial in the future.

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Second, if they did keep arriving they would defeat the purpose of the selection, and you could never get an identifiable variety or species.

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By which you only mean that it would defeat your argument. Selection has no purpose and certainly not the purpose of keeping a species in eternal stasis. Evolution is about change. It is because mutations keep arriving that evolution has occurred - from the earliest primitive life to the species we see today. If that is what you call "defeating the purpose of selection" then that's just your view. It certainly doesn't go against the role of selection in evolutionary theory - just the opposite.

I hope that you mean that there is no overall loss, Percy. Certainly alleles are removed from the population - fixation of an allele is, by definition, the loss of all others (although by the time it happens there may well be many variants). It's just that mutation increases variation is overall there is balance (in the species that survive).And I would expect a species formed by the rapid allopathic speciation expected in PE to have less genetic diversity than the parent species (quite likely less than the founding population, IMHO)

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Extremely rare means too rare to have any kind of effect on the formation of new species or varieties, which is typically a lot more rapid than assumed under the ToE. Jutland cattle. Pod Mrcaru lizards.

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I think you are making the error of assuming that mutations are irrelevant because few will beneficial mutations will arrive during the speciation event.This is a mistake because it neglects - yet again - that most mutations will occur during the far longer period (with a far larger population) between speciation events. Also the mutations that prevent interbreeding are mostly likely to be neutral (that effect cannot be beneficial until the populations meet again, and there is a possibility of interbreeding)