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

Correct. Indeed - my entire point. The whole of what though? The genes. The entities that experience reproductive sucess are genes - not individuals since some individuals are incapable of reproduction. Altruism doesn't have to be an act of will or decision. The individual ants aren't being altruistic in the sense we are used to - they are being selfish by making sure that their genes get passed on. They do this by making sure their sisters and brothers are able to protect the reproductive members of the community whose role is to directly replicate the genes. I agree that natural selection cannot happen on the individual members, nor can it happen on the Queen. Individual ants don't get selected. Their genes get selected to replicate into the next generation (or not). It is not the colony that gets selected to replicate, it is the colonies genes. The colony is more than just the genes - there are plenty of things that are included in the set {colony} that do not and never will be copied in the next generation - including exact numbers, exact actions, exact phenotypes. These things are not copied. The genes are largely the same from generation to generation, though some increase in frequency, some decrease, and some are lost. I understand the metaphor - as I have previously said. And I agree it has its uses. However, smudging the lines on what is and what is not an individual based on reproductive capability is dodgy grounds, for reasons I have already highlighted. However, genes do replicate - that is their defining feature. Individual genes are the true individuals that are the subject to natural selection. The hallmark of a solid theory is right here. The genecentric view doesn't have to ignore these exceptions. These workers don't suddenly become individuals having been limbs or organs or appendages all their life previously. They have the same genome they always did (give or take normal intra-genome mutational events of course) - those genes are working to replicate themselves through the tactic of emergency queen-duty replacement.

---

We don't even have to look at insects - several social mammals exhibit similar quandries to the individualist. Consider individuals that voluntarily decide to not reproduce - perhaps it is a society with an alpha-individual or alpha-group who are permitted to reproduce. An individual that is not permitted should (according to the individualist) attempt to mate anyway...otherwise they will be selected out. However, this doesn't happen nearly as often as the individualist model would predict.The lesser males/females in this group are charged with other duties to the group. Things such as lookouts, childcare, parasite removal etc etc. Are these individuals also 'appendages'? Of course not! They are individuals. They are protecting their genes, and helping them replicate. The genes that are responsible for instructing the individual not to mate are looking out for themselves! If these individuals did mate, there could be overpopulation problems - the group's resources will be pushed to the limit, and more of them will die. That means less genes survive, which the genes do not want to happen since their only goal is to replicate. Those genes that replicate well survive, those that don't get selected out.

Percy, I simply don't agree with you, and furthermore I don't write "nonsensical ramblings." (Your attitude causes me to think that you have not read very much of S. J. Gould.) You have not yet convinced me that, even with cartoon characterization for a colorful spin, all reproducing individuals experience natural selction.Thus far, we have established three schools of thought on the operational definition of natural selection:1. Natural selection selects or selects for groups. For example, crashfrog wrote in Message 3: 2. Natural selection selects or selects for individuals. For example, Quetzal wrote in Message 67: And Percy wrote in Message 66: 3. Natural selection selects or selects for for genes (or kin). For example, Modolous wrote in Message 63I happen to agree with Modolous, mostly, if more emphasis is placed in allele frequencies. Individuals don’t get naturally selected, or selected for, not in the Darwinian sense.But there is another issue here: Does natural selection, in and of itself, amount to evolution? Or does natural selection only lead to eventual evolution?I’ll think Darwin saw natural selection as the actual evolutionary event, or as its cause, because he explained it (standing on Malthus’s shoulders) as an active mechanism or agency of evolution. While I agree that evolution can happen without natural selection”via random genetic drift, for example, as crashfrog points out”I don’t agree that natural selection and evolution are NOT the same thing. Indeed they are, if one views NS in an active context. Why would Darwin even bring up the idea of natural selection if it didn’t explain how biological evolution works in the active sense?To me, the Darwinian meaning of natural selection is best seen in the active context. You however prefer to view natural selection is the passive context. Which one of us is right?”HM

How did you get that from what you quoted?

quote:

---

Even in a population undergoing no appreciable selection, genetic drift is causing changes to the allele distribution of the population.

---

Those were my words, but I don't see where I used the terms "natural selection" or "groups" in any of that.Go back to the classic example - bacteria and antibiotic resistance. Individuals who are resistant survive, individuals who aren't, do not. The subsequent generations are all the descendants of those individuals who survived, which means they're also resistant, and so now you have a population that has evolved resistance by selection of individuals.The things you write are nonsense, because apparently you don't understand what words mean. That's the only explanation I can offer for why you understood what you quoted to be referring to "natural selection of groups," language that does not appear in the quoted section. A house has walls and a roof, but does that mean that a roof is a house? Or that a wall is a house? You're confusing the process with the result. Natural selection is one of the processes that result in evolution of populations.

As I said in the very message you're replying to, everyone is just explaining the same thing to you, but in different words and from different perspectives. There are not "three schools of thought" about natural selection. It's a simple concept with only a single school of thought. I hope Modulous sees this, because it makes clear that you understand natural selection neither in terms of genes nor of individuals. Darwin didn't know about genes. He described natural selection in terms of selection of individuals.What was it about the analogy of natural selection to artificial selection that you didn't understand? People keep explaining natural selection to you, and you keep asking what it is. I see no evidence that yet another of my explanations is finally going to do the trick, maybe someone else will finally find the right words.--Percy

How do you figure? This is precisely the definition of natural selection Darwin and Wallace developed. NO! How many times do you have to be told? You even quoted us in this post on this subject! Evolution is the result of natural selection operating on individual members (or suites of genes if you like Mod's construction better) over generations in a population. Natural selection is (one of) the mechanism(s) of evolution. It is NOT evolution. Populations evolve. Individuals (or genes) are selected. There is no disagreement here. Good grief - you even state it here! It is the agency or mechanism of evolution! Why do you keep repeating the nonsense (and apologies, but that's what it is) about individuals evolving if subject to natural selection? And here again, for some reason, you lose it. I really and truly do not understand what element of the concept you're not grasping, Hoot. I really don't. Setting aside for the moment whatever it is you're trying to convey with the "active context" and "active sense", which, since they aren't terms used in science as far as I know, are inherently meaningless (you'll really need to expand/explain what you're trying to say), Darwin absolutely DID use natural selection as the explanation for biological evolution. In fact, it was his (and Wallace's) key insight into the mechanism of evolution - natural selection - that was so revolutionary. Up until then, various folks from Lamarck to Erasamus Darwin could see that evolution occurred - but nobody until Darwin came up with a how that fit all the facts.

quote:

---

2. Natural selection selects or selects for individuals....

​

3. Natural selection selects or selects for for genes (or kin).

---

I suggest that right now. you don't worry about whether it is the individual organism or the gene that is being selected. It isn't important to the definition of natural selection. Try to understand the basic concept first; complications and extensions to the basic concept can come later.I will repeat my earlier attempt at a definition: Note that I made no mention of whether it is the individual or the gene that is being selected. All I have done is define natural selection in terms of observable phenomena, namely that some individuals leave behind more progeny than others, and that this difference be due to inheritable characteristics.Whether the "individual" is the organism or the gene can be put off later, after it is demonstrated that you understand the basic concept.

---

Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine

All right, thank you, everyone. My education is coming along nicely. You teachers have been so kind and polite about my corrective surgery. Just to be sure I have things right, though, maybe you could critique these two statements about the agencies of evolution:1. The allele frequencies of population A over time t remain unchanged, owing to the absence of selective pressure and/or random genetic drift.2. The allele frequencies of population B over time t change, owning to the presence of selective pressure and/or random genetic drift.More nonsense?”HM

And we can add another:3. The allele frequencies of population C over time t remain unchanged despite the presence of selective pressure.4. The allele frequencies of population D over time t change despite the absence of selective pressure and/or random genetic drift.Both of these are possible as well.

---

Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine

That can't be right, can it? Even the maximally simple population, the Hardy-Weinberg population, moves towards equilibrium, doesn't it? And wouldn't mutation also cause changes in allele frequencies?

I'm going with #5, then, because allele frequencies must have nothing to do with selection pressure and/or random genetic drift. Hmm, I wonder what accounts for them. Morphogenic fields? Parallel convergences?”HM

quote:

---

...allele frequencies must have nothing to do with selection pressure and/or random genetic drift

---

If you say so. But I think you are again demonstrating how little you know about the subject.Edited to add:
I still think you should be concentrating on understanding the basic concepts before trying to add complications.Oh, and happy birthday. I hope you have a good one.Edited by Chiroptera, : No reason given.

---

Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine

Thank you. It is a good one, but a wet one here in the Puget Sound region.I take it, then, that you disagree with Modulous, who wrote in Message 136: To explain NS and other agencies of evolution, I think you have to focus on the replicators, which are the genes and their alleles. Replicators are the biological entities that get selected and evolve. Individual organisms are not replicators. They do not replicate themselves, not as unique individuals. They only reproduce more unique individuals. And what about the worker ant individuals (re: Modulous's discussion) that don't reproduce at all? Would you say they get naturally selected against? (Are eunuchs and homosexuals naturally selected against?)”HM

As I have been saying, I think it will be more fruitful if we were to focus on the basics first; complications like eusocial species can come later.I will repeat my attempt at a definition: First, this definition makes no mention of which is being selected, the organism or the gene. It simply makes a simple observation: some individuals do not reproduce as much as other individuals. Whether the invisible hand of natural selection is actually pointing to the individual that is not reproducing or to its genome isn't yet important. I am merely linking natural selection to the most observable phenomenon.In fact, I suspect that Modulous will basically agree with this definition (although he might, and should, have some reservations about details). Neither he, nor anyone else, has objected to this since I have proposed it twice, so I am assuming that most of us are in broad agreement that it is a useable definition.I would suggest one or two fixes myself, now that I think about it, but let's see what the objections to this definition are first. In particular, I am interesting in seeing what your objections are. As far as I know, this definition is or is close to the actual definition actually used by biologists.

---

Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine

Let me step in, and say that this is pretty much bang on! I'll quote Dawkins yet again, since he is the prolific, understandable, modern writer on genecentric selection. From {New Scientist}I know that copy/pastes from sites are frowned upon and 'own words' are looked for, but I can't resist citing this 'compromise' site. Which basically mirrors what I have been saying. From here.Not really debating your position here. I thought bringing together my thoughts in the often more carefully crafted fashion of professional writers would help clarify my position to any who may have been confused.As an addendum, I'm arguing a specific position heartily, because it is under represented here. This is a genuine debate, a genuine controversy as it were. It's fascinating to hear both sides, but I generally favour the utility of genecentric vision for truly understanding what is going on - but I accept the pragmatics of discussing things at higher levels such as organism /family/colony/race/breed/species/[insert arbitrary grouping, as long as that grouping is done on the basis of common ancestry] level.I just think it is easy to go from the pragmatics of this view, and get a little carried away with it - finding oneself in a position of having difficulty explaining certain things.

Heh, this is what I've been saying all along - although obviously not as well. The last paragraph in your quote also sums up well - the genotype is indeed what gets replicated (outside of clonal species, of course). That is never in question. Throughout I've been talking about what gets selected - not what gets replicated. Perhaps that's where our miscommunication arises?