Is there more than one definition of natural selection?

In what way? I thought you weren't looking from the genes eye perspective, which would seem to be the only one from which this statement would make any sense whatsoever.This just suggests that you don't even understand what 'differential reproductive success' means.TTFN,WK

There are thousands. Natural selection is a result of the action of the environment on an organism with a particular phenotype, and at the gene level with particular genes and gene complements.Until we understand every interaction between an organism and its environment and the contribution of those factors to the organisms reproductive success then we will not have a full accounting of the cause/effect relationships shaping natural selection in that population and the various genotypes/phenotypes within it. Well since it is a general definition he would be unlikely to mention more specific forms such as sexual selection and artificial slection. As to mutation this is a significant source of the variation upon which natural selection can act but not a component of natural selection itself. I'd say it can be both in as much as the constitution of any generation resulting from previous selection will form part of the environment shaping subsequent selection. I'm not sure that any of the things you have said here actually reflect the disagreements that arose on the previous thread.Maybe you should read some of Philosopher of Biology Roberta Millstein's work on the relationship between Genetic drift and natural selection and their respective roles as causes of evolution. The page I have linked to contains further links to the full text of many of Millstein's writings. I think that her paper “Are Random Drift and Natural Selection Conceptually Distinct?” is particularly relevant.TTFN,WK

Your reply ties in with the paper I was suggesting you look at. The question is whether the co-fertilisation or subsequent change in allele frequency were affected by heritable differences or just the result of stochastic noise blind to the phenotype/genotype.In other words this may lead to evolution in terms of the allele frequencies in the next generation being affected but it is not natural selection as the process is blind to the genetic makeup of what it is acting upon, similar to the effect of genetic drift. Is it a measure?TTFN,WK

Then you are going to be very uncomfortable. Positive selection, negative selection, purifying selection, disruptive selection and frequency-dependent selection are all frequently discussed forms of selection.I think the main problem is that your view of what NS encompasses is too simplistic.TTFN,WK

Only if you want to just start making stuff up. Roberta Millstein is a she. As to what she is saying you seem to have understood some of her conclusions but decided to frame in exactly the opposite way to how she presents them.Rather than saying there are situations where Natural selection and Drift are indistinguishable she is arguing against the position that they are always indistinguishable.AS you say the key criteria is whether one considers NS a process or an outcome, but this is a distinct question to whether it is a cause or an effect.I only think of NS in terms of being a process rather than an outcome but I think of it as both a cause and an effect in different contexts. The outcome would only be the way we try to measure the extent to which the process of NS was operating on the population.TTFN,WK

I agree with a lot of what you say here, since it is you talking about a paper I already said I agreed with .I would take issue with one thing however. Why do you still insist on saying that preferential mating (Sexual selection) is separate from differential reproductive success (Natural selection). You can certainly have NS without sexual selection but unless you are talking about a meaningless case of preferential mating based on non-heritable traits I don't see how preferential mating can be anything other than directly connected to differentials in reproductive success.Why do you persist in trying to separate sexual selection from natural selection?TTFN,WKP.S. There are some quite nice simple simulations of a number of relevant things at the site EvoTutor . You will need Java runtime installed to view the simulations.Edited by Wounded King, : No reason given.

No one has said they are an equality, we have persistently said that sexual selection is a subset of natural selection. It is one of the many 'environmental' factors which can form a selective pressure for a population. How? It is obvious how migration into a population, mutation and genetic drift can act as countervailing processes, but how do you propose sexual selection does so. There are lots of selective pressures that can pull/push in different directions but they are all incorporated into NS so how can selective pressures be counter to NS itself?TTFN,WK

Natural selection is not one force. There are a large number of environmental factors producing selective pressures which act upon a population. It is the action of all these pressures to selectively affect the genetic constitution of the next generation which constitutes natural selection. These pressures need not all act in the same direction with regard to a particular trait.Sexual selection is simply one of these factors. You can no more separate it from NS simply because it acts against the directional trend of any other particular selective pressure that you decide to term as belonging to NS than you could separate out that pressure for acting against the trend produced by sexual selection. They are both selective pressures and therefore both part of natural selection.Why do you think sexual selection is particularly distinct? This has to be the stupidest example ever. Your scenario has sexual selection strongly reinforcing NS. Good looking ones mating together is assortative mating for similar phenotype. The bad looking ones are more fecund. Natural selection will favour the bad looking organisms because of their more fecund genetic elements. By assortatively mating the good looking organisms are strongly reinforcing the direction of natural selection by not mixing their less fecund genetic material with that of the bad looking ones.Without this sexual selection you would expect the more fecund genetic elements to quickly predominate, and if they were genetically linked to ugliness then that too would rise to prominence. If you add in your proposed assortative mating it happens much quicker as the increasingly larger fecund population only interbreeds and flourishes while the less fecund one does not incorporate the fecund genetic material consequently lags behind and is swamped.TTFN,WK

Did you just not understand anything I wrote? You certainly haven't addressed any of it. We aren't talking about evolution, we are talking about what constitutes Natural Selection. You think I am too selection oriented in my thinking about natural selection? Perhaps that is why I think you are talking nonsense. Well I don't, so this is one more on the growing list of things you are wrong about. No, I see all selective processes as forming independent vectors whose results when summed produce specific directionalities, including stabilising and disruptive ones, in the allele frequecies of a population. Please don't tar me with your own inability to think of NS as anything more sophisticated than just an inchoate concept.I didn't trivialise non-selective forces, I just don't consider them part of natural selection. They are the noise that disrupts natural selection's signal. Such as? This sort of glib non-response is verging on the trollish. You certainly do.

Probably not I grant you, but any degrees of interaction will be subsumed into the final result either way. The independence of each process is not the main issue, the fact that all of the selective processes contribute to natural selection is. Yes you are, the question you are currently refusing to address is about sexual selection, not mutation or gene flow or genetic drift. That was one of the key points of Millstein's paper. We don't have to be able to empirically dissect out the relative contributions of selective and non-selective factors to the resultant gene frequencies to be able to say that they are conceptually distinct from one another.TTFN,WK

In what way is sexual selection conceptually distinct from natural selection?Or did you once again forget that sexual selection isn't a non-selective factor? The clue is in the name.Once again, no one has said that NS and SS are the same thing, they have repeatedly said that SS is a subset of NS and therefore not seperate and not a non-selective factor.TTFN,WK

Ugh, that has to be one of the the sloppiest and least accurate descriptions of the process I have seen which still used all the right terms. DNA isn't transcribed by mRNA but to mRNA by the RNA polymerase. The events you describe as occurring on the way to the ribosome actually occur within the ribosome, the ribosomal machinery is as much a part of the translational machinery as tRNA is not merely some subsequent stage of assembly. tRNA isn't actively translating anything, merely bringing the write amino acids to the site of translation.No doubt once again pointing out your tenuous grasp of molecular biology is only ankle-biting.TTFN,WKP.S. Care to address Message 66 yet?

Only the Edinburgh site makes a claim that sexual selection is distinct and if you look at the definition it gives for Natural Selection... Sexual selection seems to fit right in with this definition since it clearly influences an organism's chances of reproduction. Edinburgh seem to have treated reproduction and fecundity as the same thing, which they aren't.Be that as it may, I agree that if your definition of NS only encompasses survival and fecundity then you can make a clear case for a distinction. The real question was whether Hoot Mon could make such a case, and he seems to have singularly failed to do so.Even if we can't necessarily agree on a canonical definition of NS or SS we should still be able to agree on the implications of accepting specific definitions.TTFN,WK

You have yet to provide anything to cause me to revise my opinion, your example was one where sexual selection and natural selection would cooperate, the exact opposit of what you were trying to demonstrate. If you think it wasn't then explain why. It seems that whenever you get your basic molecular biology wrong it is merely perfunctory. ___
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Oh rly?Please see here, here, here,here, here, here and most of the rest of the internet. Since non-random mating and sexual selection are not the same thing this makes your point rather irrelevant. You may have seen what AZPaul wrote upthread. If you want to define NS narrowly as only selection acting on survival and fecundity then I agree that you can discriminate between NS and SS as forces. Then you need to add in a whole lot of other selective forces which are not sexual, survival or fecundity. I prefer to treat the various element of fecundity, survival, sexual, gametic,viability and whatever other forms of selection act upon heritable genetic chracteristics to influence allele frequencise in subsequent generations as all elements of Natural Selection.TTFN,WK

Because while you can have non-random mating without sexual selection you can't have sexual selection without non-random mating. The difference is in the non-randomness of the mating acting upon heritable traits.If females chose not to mate with males of a certain colour, but that colouration was due to an entirely random environmental factor, then you would have non-random mating which would not effect any meaningful selection. Um, no. Quite clearly not. I see all the selective forces which act upon heritable genetic chracteristics to influence allele frequencies in subsequent generations as Natural selection and I see Natural selection to be one of the factors in evolution, but along with mutation it is one of the most important ones. I already agreed previously that mutation, gene flow and genetic drift could all effect
changes in allele in a population, and thereby evolution, and that these were distinct from natural selection by way of being indiscriminate as to the genetic constitution of the population and organisms.I will caveat that by saying that mutation can be affected by the genetic makeup of an organism, and there is a good case to be made for natural selection having produced a number of strategies for modifying the rates at which variation is produced in some areas. Equally there may be genetic bases which predispose an organism to more frequent migration from its original population, but these are unnecessary complexities to the basic concept of these forces being essentially non-selective.Can you give us any idea where you came up with what you put forward as my position?TTFN,WK