What exactly is natural selection and precisely where does it occur?

I agree, and people (including me) have done that in their replies to the messages I pulled your quotes from.Although I replied to your message, the content was actually intended for Modulous. He believes that you've been misinterpreted and never intended to say that the process of natural selection includes evolutionary change, and I thought I could persuade him otherwise, but I guess not.This rebuttal from you fails to address or even indicate an awareness of the key points and is illustrative of your grasp of these concepts: Moving on: First, supposedly you're addressing my claims that you believe that natural selection includes evolutionary change and that sexual selection is not selective, but this doesn't address these claims in any recognizable way. For example, nothing I said was related to microevolution. And second, I'm unable to identify a meaningful point, or even any meaning at all. The "evenness of reproductive success" is the not same as natural selection. Differential reproductive success is not natural selection - it is a consequence of natural selection. Natural selection operates on phenotypes (or "gangs of cooperating genes" if you wish) and provides the opportunities for reproduction as a consequence. I don't know what a "microevolutionary event" is, unless you just mean birth or cell division, and its hard to understand how changes in allele frequency could not at a minimum be microevolution, since changes in allele frequency in a population over time is the very definition of evolution.If you have some concrete points to make then could I suggest using an example instead of speaking in the abstract.--Percy

Indeed. As I said, I'd not use the word include to describe my position for reasons you just highlighted. Indeed. Let's do as I suggested and throw the word include out because it is clearly the wrong word for the job. No wonder Hoot Mon is getting confused. So if germ line DNA mutates, that is not evolutionary change. If an asteroid wipes out 90% of all organisms, that is not evolutionary change. I define evolutionary change in terms of gene/allele frequency change as per the modern synthesis. You seem to be putting an Ultra Darwinian POV forward.Let us establish what we agree on.

1. Hoot Mon says that when Natural Selection occurs evolution occurs.
2. Hoot Mon says that evolution can occur without natural selection occurring.
   

Do you agree that Hoot Mon has said both of the above? I can provide the quotes again if you'd like.If Hoot Mon has said both of the above, then what is the relationship between natural selection and evolution according to Hoot Mon? You say that Hoot Mon believes that evolution is a subset of natural selection (that natural selection includes evolution) - I challenge you on this since the second thing Hoot Mon says is not consistent with this.I agree that Hoot Mon is not using precise terminology, but your interpretation is nonsensical and mine isn't. You'd have a point if it weren't for Hoot Mon's statement number 2. It is straightforward. I am using the totality of statements that Hoot Mon has made that I have read to come to an understanding of his complete position. You are taking each individual statement as the totality of his position and saying that he is flip-flopping (or you ignore certain statements he makes that contradict your view of his position). His statement about active contexts only looks meaningless because of your view of what he is saying. With my model of Hoot Mon's position this statement goes from meaningless to meaningful but with ambiguous terminology. I'm not sure that is true. Hoot Mon is asking 'what exactly is natural selection?' He is not asking 'what basically is natural selection?' He doesn't understand it because it doesn't make sense. I don't understand it! When you really dig for what exactly natural selection is, the individual point of view ceases to make sense. Much like relativity goes bananas when you ask 'what really is the fabric of the universe?'.The individual point of view only makes sense if you ask 'Can you please give me an illustration of natural selection at work in the real world?'See Hoot Mon's first response in this thread: What level does differential reproductive success operate on? What is actually experiencing differential reproductive success? Many people have said c), but those same people struggle with c) in some situations, and have to resort to d) (see ant colonies discussion).I say e) is where the real action is, and that just gives the impression of d, c, b and a when you take a suitably large step back. I have never seaid includes=implies. Nor have I ever said natural=artificial. I have taken great pains to discuss the differences between these words so how you got to that is beyond me. If you read this post and still conclude as above, then fair enough we'll leave it there. I still think that it is just a communication issue not one of understanding the issues. I'll post a grand 'Hoot Mon's position' post for you to peruse and we'll leave it at that.

Hi Modulous,I've been mulling over your "natural selection isn't natural and artificial selection isn't artificial" position (see your Message 186) trying to make sense of it. I wasn't originally going to address this as I thought it would tend to draw the thread off-topic, but I'm also concerned that it might be confusing to this thread's goal of composing a coherent definition of natural selection for Hoot Mon, so I've changed my mind and decided to respond.I'm not going to address your main position directly. The question of whether natural selection is best viewed as individual-centric versus gene-centric is almost like one of those "what's the best text editor" religious wars, i.e., it includes a large element of individual preference. It doesn't bother me at all that some people prefer emacs (the best editor in the universe) while some other egregiously confused people prefer vi (an abomination exceeded only by teco). In the same way, I don't care whether someone prefers the individual-centric or gene-centric view of natural selection. I think debating these different perspectives can be very interesting and illuminating, but I don't feel impelled to participate at this particular time.But I do think that clear communication requires agreement about the meaning of terms, and so it is this from your Message 186 that has raised my concerns: I've read this a number of times now, as well as the clarification that follows, and I can't find any interpretation that alleviates my concern. The terms "artificial selection" and "natural selection" have had clear definitions for nearly 150 years. These definitions have been updated and modified in light of new knowledge and improved understanding, but the distinction that artificial means man-influenced or directed while natural refers to a creature's natural habitat have not changed.There's no argument that man is actually as natural as everything else. That may not be the position you were advocating, I'm having difficulty deciphering your position, and I just mention the "man as natural" position because it's the only interpretation I could come up with. But the important point is that whether that is your meaning or not, or whether some other definition is your meaning or not, it is not the way we traditionally view or talk about artificial and natural selection.Clear communication requires that we agree upon the meanings of the terms we use. It is perfectly fine to introduce new, more specialized definitions for common words in order to assist communication in technical discussions, but one should never introduce new definitions for what are already specialized terms with specific meanings. Only confusion can result.So if your position is that I'm misinterpreting the meaning of artificial and natural selection, then please correct my misunderstanding (hopefully in terms I can understand). But if you're actually trying to substitute your own preferred definitions for these terms, then I think that is a really, really bad idea.--PercyPS: By the way, do you think the way we spell is hereditry? Might there be a dietry contribution? Is it perhaps involuntry? A momentry lapse? Your secretry's fault?

I don't think either of us is going to budge on the issue of whether Hoot Mon understands the concepts behind the terms he's throwing around. I'm content to let Hoot Mon's foot-in-mouth rate let people make up their own minds.--Percy

Message 1
I agree with this. There might be uneven reproductive sucess in a population that has no genetic variation and never will - this would not be natural selection. Agreed. Hoot Mon shows that he understands the individual point of view of natural selection but that it isn't necessarily what is exactly happening. I great short summary of the issue that has faced biologists. He includes some of the problems that face individual selection (altruism) and mentions that several other proposed selection locations have been abandoned by the majority of the community. He also states that natural selection isn't the only cause of evolution, which I think everyone agrees with.The only part I disagree with is the preferential mating part.

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Message 6Though, his earlier statement would lead me to the conclusion that he is now approximately equating diff. reproductive success with natural selection for convenience.

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Message 12
Once again driving to the heart of the issue.

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Message 44But wait. What if Johnny, a mere pawn in the game, was a strategic move on the genes' part, operating under the principle of genetic altruism? Hamilton, Dawkins, et al. have argued that genes can be quite strategic in their adaptations for survival, even to the extent of demonstrating altruistic determinsim. So, individual survival may NOT be the real focus of natural selection; instead it would be focusing on the genes and their alleles, or on changes in their relative frequencies thereof.[/qs]Bang! Again, continuing with theme that the genecentric view is better than the individual view. Individual survival (survival selection) is not the real focus - but looking at genes it begins to make more sense.

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Message 49This is where Hoot Mon gets confused, and it is easy to do. In my view natural selection is pressuring the handicap and is also pressuring against the handicap. The ideal strategy is to be a little bit handicapped, but also able to survive and reproduce.Hoot Mon seems to think that these are two seperate forces, when they are just one force acting in two different directions. He calls one force preferential mating, or sexual selection. He doesn't need to though!

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Message 57If any one or more of these conditions are met then biological evolution may occur. NS does not always play a part, but it may eventually have a role in selecting for changes in the allele frequencies resulting from the consequences of the other evolutionary 'forces'.[/qs]Once more - an accurate overview of the theory of evolution. There is disagreement at play as to how many distinct forces there are (sexual selection for example) and the exact nature of those forces, but not a terrible description.

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Message 129
If Natural selection then evolution.
Hoot Mon has earlier said that if evolution then not necessarily natural selection (could be drift for example).Mathematically this relationship is natural selection=>evolutionI suspect Hoot Mon either forgot or was not aware of this relationship symbol so used = instead earlier in the post. We don't see Hoot Mon ever say Evolution = natural selection, and I suspect there is a reason for this, and that is that the relationship is one way only. From Hoot Mon's own words this seems crystal clear. And I agree.

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Message 130 (chiroptera) And I agree with this. The only time natural selection occurs is when a heritable trait is passed on (or not). Heritable traits that go towards reproductive sucess are selected for - literally meaning that more of these traits will be present in the population as time goes on. Heritable traits are so because of genes. So genes that create these heritable traits get selected for. Thus natural selection is selecting genes, not individuals.

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Message 147And this is a good question, once again highlighting the issue at hand.

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That should suffice to explain how I'm getting to where I am with regards to Hoot Mon's position. It seems clear to me, but I've read a lot of Dawkins relatively recently so I'm used to the way Hoot Mon is explaining his position so am able to understand even when he sometimes falls short of the explanatory skill of Dawkins. I've tried to use my understanding to help Hoot Mon with the explanation of this position - perhaps I failed, I cannot be sure - but it has been a fascinating discussion nevertheless.

Hi Modulous,We evidently don't agree on the definition of natural selection, and I think it might be profitable to examine this in greater detail. I'm only going to discuss your views, or views you say you agree with. I would have said the exact opposite, that differential reproductive success is a possible consequence of natural selection. Let's examine this more closely, not by examining one of the many exceptions like ant colonies with thousands of sterile members or asteroid strikes, but by examining a straightforward example of a sexual organism's life cycle:Hopefully we need not quibble about details, such as the whether sperm/egg conjoinment is part of natural selection or not, and whether we need to be more general or more specific. I can see such things either way and don't think them important to this discussion.Differential reproductive success is not on this diagram because it is not the same thing as natural selection. Differential reproductive success is the result of natural selection operating upon the differential fitnesses of individuals for the particular environment.Unlike you, I am not arguing that there is only one proper perspective, and I am not arguing that your perspective is flawed or misleading. I'm arguing that this is one of the correct perspectives, and furthermore, that as far as communicating concepts go it is one of the simplest and most easily understood.--Percy

Oh, I wouldn't want to ignore the demolition amphibian. (He's too much fun to squish!) So, if you would kindly itemize my errors, one by one, I will kindly address each one. I'll be fair, too. If I truly wrote in error I'll admit it. But if the intentions of my words have been mistaken by others I'll try to set the record straight.”HM

You're free to respond to any of the innumerable posts where I've done just that. It's specifically your misapprehension that sexual selection is non-selective that I've been interested in engaging you on. Others have taken on the task of rectifying your idiosyncratic "understanding" of natural selection in general.

Wow. This thread has definitely moved on since the last time I was able to participate. I don't want to go back and rehash old ground, but I would like to make a couple of final points and/or clarifications, if it's not too late. Right. I'm not sure why you brought this up, since it's not a point of disagreement. Further up-thread, I mentioned to Hoot that I felt that the term "natural selection" was a poor one, precisely for the reason you mentioned - all selection is natural. I also mentioned to him that the terms "natural" and "artificial" have been in constant use for ~150 years, so it's unlikely that we're going to see the last of them.As to the bolded part, I don't disagree - normally when we are discussing NS, we're discussing it in terms of evolution. Perhaps it's only because we interpret the purpose of this particular thread differently, but I was under the impression that we were trying to discuss NS more or less in isolation - not evolution. After all, the original question was: "What exactly is NS and precisely where does it occur?". Evidently we've been discussing two different things - and that may be why you're not understanding my position. I understand the genecentric viewpoint well. It is nearly purely a way of looking at multi-generational selection response. It is not a good way of discussing NS itself - except in the context of evolution. I have stated multiple times on this thread alone that in the context of the adaptive response of taxa to NS (i.e., evolution), the gene is far and away the best (and I'd go so far as to say the only) way to cogently discuss the question.Let me go a bit further, however, and make two points on "practicality". Hopefully you'll be a bit clearer on my perspective. My discipline is focused on discerning, describing and evaluating the interrelationships of whole organisms to one another and to their environment. As such, we are concerned with phenotype, and outside of the context of population dynamics (i.e., response), in many cases it doesn't even make sense to talk about genetics. In fact, we most often don't even consider the individual organism - we're concerned with populations, communities, or entire ecosystems (c.f., the subdisciplines of macroecology, landscape ecology, etc). One of the things that goes along with this is trying to understand selection pressures in isolation from the organisms being affected. It doesn't matter whether these pressures are a bloody great rock or fluctuations in a local microclimate. Therefore, it is more "natural" for me to think about selection (not evolution) in terms of the effects on individuals during their lifetimes, than the effects on populations over evolutionary or generational timescales - and to describe NS in that context.The above brings me to a second, subsidiary point that may have some relevance for this thread. You have stated repeatedly that you feel the genecentric view is "easier" to use to explain NS to those without a biology background. I very much disagree. People (erm, non-biologists anyway) don't walk outside, look around their backyards, and see genes. They see individual plants and animals. I have led enough natural history ecotours, and given enough presentations to non-scientists, to have learned that the best way of providing simple illustrations of complex concepts (from the effects of ecosystem degradation to symbiosis to adaptation and evolution), is by couching the explanation in terms that people can intuitively grasp. In other words, discussing NS in terms of organisms. The genecentric view merely introduces an additional level of abstraction that can get confusing (as can be seen on this thread). If the purpose of threads such as this one is to describe NS to folks who don't have a bio background, then I submit that the individual organism is the best way to do it.If I was talking to scientists, then I would use whichever viewpoint best illustrated whatever point I was trying to make, at whatever level was appropriate. And if I was describing evolution, then I would use (and have used) the genecentric position - because that's what evolution is all about.Hope this clarifies.

Hi Hoot,If you still have questions on anything else in my post 175 let me know. Since this thread has moved on quite a bit, I don't want to waste what little time is left. I would like to try and clarify one point, however. Like any metaphor, we've got to take it with a grain of salt, and be careful of how far we push it. Here is a very simple illustration/explanation for NS that I have used in the past, that may explain what I was trying to get across. Remember, please, that I used the seive analogy in response to your question: They used to sell a toddler's toy (I think it was one of those Fisher-Price things), which consisted of a clear plastic cylinder divided vertically into separate compartments by plastic plates with different size holes. You put a bunch of different colored and different sized plastic marbles in the top, shook the thing, and the marbles cascaded down through the toy. The marbles got sorted by size, with the biggest staying at the top, and the littlest tumbling through the various holes and ending up at the bottom. The rest are sorted by size to the different levels. Let's say that all the littlest marbles are also red. The toy "selected" small, red marbles, in other words. However, it didn't select for red color, it selected for size. There is selection of red marbles, but only because all the red marbles are also small. Thus the individual selection filter doesn't "obviate the selected for" aspect. It actually explains the difference between selection for a particular trait and selection of un-related traits.

Maybe, like Jesus, I have suffered for your sins. And, like Jesus, I am quite willing to be crucified for the sake of clarity about what natural selection is and where it occurs.I am not immune to foot-in-mouth disease. I am one of the tawdry few who have to live with this crippling affliction. But maybe it is a treatable condition for me, if the doctor would please give me some good medicine. Perhaps the doctor could examine me by posing a few simple questions:1. Hoot Mon, do you believe evolution automatically means natural selection? (Answer: No.)2. Hoot Mon, do you believe natural selection automatically means evolution? (Answer: NO.)3. Hoot Mon, do you believe an evolutionary event can happen without natural selection? (Answer: Yes.)4. Hoot Mon, do you believe some evolutionary events can be attributed to natural selection? (Answer: Yes.)5. Hoot Mon, do you believe all evolution events can be attributed to natural selection? (Answer: No.)6. Hoot Mon, do you believe sexual selection is the same thing as natural selection? (Answer: No.)7. Hoot Mon, do you believe sexual selection can occur without natural selection occurring? (Answer: Yes.)8. Hoot Mon, do you berlieve that natural selection can occur without sexual seletion occurring? (Answer: Yes.)9. Hoot Mon, do you believe that an evolutionary event can occur without either sexual selection or natural selection occurring? (Answer: Yes.)...Just keep 'em coming, Percy, and we'll get to the bottom of this.”HM

Excellent! Thank you, Quetzal.Let me ask you this: If the "selection" going on in your model is size-oriented, would you say that "selection" would still go on if you adjusted your model so that all marbles and and all holes were of equal size? In other words, all you did was to make your sieve non-selective for size. Does "selection" work like this on a scale of 0.0 to 1.0? Would it be fair to say that natural selection occurs even when there is no "selection" goin on?”HM

I have to say, I don't see these questions as especially probative. It seems to me that your time would be better spent, not worrying about whether or not sexual selection is exactly the same thing as natural selection, but in thinking about the effects that:Selection by environment
Selection of males by females
Selection by human breedersetc. might have on the genetics of a population, as opposed to the effects that genetic drift might have on the genetics of a population, as opposed to the effects that mutation might have on the genetics of a population, etc.The idea of thinking about evolution as a series of evolutionary "events", while perhaps applicable in a narrow set of circumstances, doesn't seem like a fruitful approach to understanding evolution in general.It's easy enough to imagine the example of antibiotics and bacteria, and to imagine that the introduction of the antibiotic to the population is the "evolutionary event", because that's the single event that, in the short term, is going to have the most profound influence on the genetics of the population.But evolution in general doesn't proceed in "events"; the genetics of a population is in constant flux, constantly changing. And while in the short term we might identify:the introduction of a new species in the environment,
or an astronomic event such as an asteroid,
or the "founder effect" responsible for punctuated equilibrium's effect on the history of morphology,as the "evolutionary event" that was responsible for a sudden shift in the fossil record, it would be very, very wrong to imply that evolution is just a series of events separated by stretches where no evolution takes place at all. Evolution is constantly ongoing as individuals experience differential reproductive success for a variety of reasons, like luck, or their adaptations to environment (including predation and disease), or their attractiveness to potential mates. And that differential success has a non-random effect on the genetics of the population.Selection is selection. It doesn't seem fruitful to me to worry about the different kinds, except to note that we characterize them with different terms because they have, in general, different effects. Natural selection gives rise to adaptations that promote survivability, defense against diseases and predation, and enable access to new food sources (among other things.) Sexual selection gives rise, in males generally, to weapons for ritualized combat and bright displays for females. Often traits that are maladaptive but nonetheless successful in increasing reproductive success.But selection is selection, and it all works the same way - individuals with the traits being selected for have more offspring, and those with traits being selected against have less offspring. And whenever selection is occurring, changes to allele frequencies are the result, and thus, evolution.

So you're a gradualist. Gould sends his worst regards. Do you not agree that evolution can be attributed to causal factors?”HMEdited by Hoot Mon, : No reason given.Edited by Hoot Mon, : getting back to frog

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7. Hoot Mon, do you believe sexual selection can occur without natural selection occurring? (Answer: Yes.)

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This I don't understand. It is very easy to see that sexual selection is a type of natural selection from the gene-centric viewpoint.I'm not going to distinguish between NS and differential reproductive success because that makes most sense in individualist-thinking. So i'll define natural selection as I have before If you basically agree with above definition, then its clear that the genes of the sex competing for attention will have differential reproductive success due to the traits they produce (e.g. peacock tails, bird songs, etc.)On the other side, the genes of the sex that is being discriminatory about their mates will have reproductive success due to their discriminatory phenotype, i.e., they'll "choose" genes from other individuals that they'll interact with most optimally, or something to that effect.