Is there more than one definition of natural selection?

Well, of course. It's an "evolutionary force-flow" diagram. I didn't bother to inlude any "forces" that preserve the HW equilibrium.”HM

Two distinct things as everyone keeps pointing out. Sure it could, but then it would just be an element of genetic drift causing evolution in the absence of selection.If you are having an element in your selection set that includes non-selective instances then you might as well put genetic drift in there as well. You can just leave non-random mating out as when it is selective, with respect to a heritable trait, it is subsumed by natural selection and when not by random genetic drift. If you wanted you could always put smaller elements in each set to describe subprocesses, so you might have non-random mating as a subprocess of both ns and rgd. If you wanted to get really fancy you could have a Venn diagram showing where different process take part in more than one of the larger processes making up evolution.I'd also still say to take out HW since it has no place here at all.I do like the 'Pow!' explosion for evolution.TTFN,WK

I'm still waiting to be convinced that sexual selection does NOT entail nonrandom mating. If that is true then natural selection does NOT entail differential reproductive success. I like to single out nonrandom mating because it has specific meaning to the maintenance of a population's HW equilbrium. I'm using the HW equilibrium as a valid reference point for defining evolution. Why not? I think it captures the meaning of evolution concisely? A redistribution of allele frequencies resulting in a new HW equilibrium would amount to microevolution if it did not result in speciation, and macroevolution if it did.”HM

Eh? Maybe you are still waiting to be convinced because you have consistently ignored the several instances where it has quite plainly been explained to you that non-random mating can occur without sexual selection occurring. Similarly genetic drift can cause differential reproductive success in a particular generation, but it won't be consistent because it isn't based on and heritable trait. So you can have differential reproductive success without natural selection, that is why several people have tried to reinforce the importance of the differential reproductive success having its basis in some heritable characteristic.I still fail to understand your need to bring in HW at all. The whole point about evolution is it is what occurs in non HW equilibrium situations beyond fixation or the establishment of effectively fixed allele frequencies, which are only a couple of the possible scenarios, most of the processes remain and produce dynamic change in the system consistently. If you want to say these are forces which prevent a population from stabilising in HW equilibrium I could go for that, but I see no evidence that these forces need establish a new HW equilibrium.TTFN,WK

What difference does it make to the HW equilibrium”my definition of a population's evolutionary "rest state"”if nonrandom mating occurs with or without "selectual selection"? You're talking about qualitative cause/effect relations; I'm talking about quantitative cause/effect relations. Your argument ignores the posibility that the process of "sexual selection," as you choose to see it, might also run counter to nonrandom mating, thereby reducing or neutralizing its magnitude of cause/effect. Since I'm hinging my definition of evolution on the HW equilibrium, I don't care so much about why the HW equilibrium is disturbed, I care more about the magnitude of its disturbance. My diagram in Message 134 allows for the "force" of drift to influence the "force" of selection. btw: Could you provide an example of a "trait" that is NOT heritable. Isn't heritability implicit in the term "trait"? Better to say it this way: You can have differential reproductive success without changing the relative fitness of individuals in a population. Yes. Those are the people who choose to see a three-legged-dog "trait." I argued that if one can see a three-legged-dog "trait" then one might also see a three-legged-dead-dog "trait"?Creeping Lamarckism is a constant problem.”HM

The HW principle describes a theoretical equilibrium for genotype frequencies at a given locus. Calculating the HW equilibrium relies on eight different assumptions. The HW equilibrium does not describe what we see in the real-world because no natural population fulfils all the assumptions made in the calculation.
Note that any kind of selective pressure, not just sexual selection, can cause a departure from the theoretical HW equilibrium. This is the point of the HW principle, the extent to which real-world genotype frequencies depart from the theoretical equilibrium indicates the amount of selective pressure a specific gene locus experiences. It was never a description of real-world populations.

And this from the person complaining that we are all focussed on natural selection as an outcome, you seem to have just said that you aren't interested in anything other than the extent the outcome deviates from the expectations of HW. No. You may choose to define it so personally, but that is just yet another of your idiosyncracies. Heritable traits are just the only ones that are generally relevant to evolutionary biology. But that isn't an argument. Since one isn't discussing heritable traits these are simple any descriptive feature which can be ascribed to the organism, and being dead fits that criterion. It is an absurd example because a dead animal is clearly excepted from being a possible contributor to the gene pool, without human intervention with modern fertility techniques, but otherwise it fits the criteria. Not for anyone here, once again you ascribe views to others which they have never propounded. Your failure to actually substantively debate anything and inability to focus on any one issue sufficiently to come to some clear resolution is much more of a constant problem.TTFN,WK

Good point, Malcolm, but what kind of exactitude do expect from evolutionary modelers? Modeling the "forces" of evolution and the results they produce is always going to be a difficult task. But not impossible. So far as modeling the real-world process and effects of random genetic drift in fruit flies is concerned, Daniel Hartl & Elizabeth Jones (in Essential Genetics/A Genomics Perspective, 2002, p. 528) show convincing experimental results from experiments performed, albiet with very small populations, to develop and test predictive models of drift, which rely of course on HW assumptions and calculations: "Figure 14.27 (A) Random genetic drift in 107 experimental populations of
Drosophila melanogaster, each consisting of 8 females and 8 males.
(B) Theoretical expectation of the same situation, calculated from
the binomial distribution."Their work must count for something in the real world. Please show me anything better if you've got it.”HM

Do you have the original reference for this work, rather than the textbook reference?TTFN,WK

And you'll probably be waiting a long time too! Sexual selection is definitely nonrandom mating. However, not all nonrandom mating is sexual selection. Just because all fast cars are red, does not mean that all red cars are fast. There is no need for HW equilibrium being a reference point for defining evolution. Any change in allele frequencies is defined as evolution, HW equilibrium is simply an unnecessary entity in defining it.I'm not entirely sure you've nailed the understanding HW equilibrium here, it seems you seem to using to mean an Evolutionarily Stable State. Any redistribution of allele frequencies is evolution, regardless of what resulted from it.

quote:

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Do you have the original reference for this work, rather than the textbook reference?

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Buri P (1956). Gene frequency in small populations of mutant Drosophila. Evolution 10(4): 367-402.AEdited by Allopatrik, : No reason given.

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Natural Selection is not Evolution-- R.A. Fisher

Those original graphs are from D. L. Hartl and A. G. Clark, 1989. Principles of Population Genetics, and the data in part A are from P. Buri, 1956. Evolution, 10:367.”HMEdited by Hoot Mon, : No reason given.

WK, can you provide a good example of a "non-heritable trait"?”HM

I used the HW equilibrium because of the five "forces" that are known to disturb it. Is there another measure of an evolutionary "rest state" that would be more relevant? Would it be better to more simply define the "Evolution*" effect as "*Redistribution of allele frequecies"?”HM

Hi Percy,Just got back from the field last night, so now have some time to post again. I'm not sure your characterizing my interactions with Hoot accurately. It's less that I think he's right about a lot of things, but rather that I discern some validity to the questions he brings up. Unlike Brad, who I've never understood, Hoot DOES seem to be on the right track fairly often. It's like trying to evaluate a boundary condition - Hoot seems to come right up to the edge, so I can't help but try and explain things in a different way, or think that if I answer the question clearly the little light will come on and he'll make the crossing. I may be wrong, of course. Or maybe it has something to do with puppies...Anyway, I think it's worth trying. I can understand yours, crash's (and other's) frustration. I may arrive at that point myself eventually. I'm just not there yet.