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

I'll repeat what I said over there. Preferential mating is, by definition, selective. The mate's preference constitutes a selection. That's why they call it "sexual selection", after all. You mean, where does evolution happen? Planet Earth. Next question.No, seriously, though. Where doesn't evolution happen? It happens any time that living things are reproducing through descent via modification. I guess maybe you think you're asking an insightful question, but it sounds like a stupid one to me. Even in a population undergoing no appreciable selection, genetic drift is causing changes to the allele distribution of the population.

Because you say so?What's known is that preferential mating is selective. It's a kind of sexual selection. It's right there in the word "preference"! For instance

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The success of an organism is not only measured by the number of offspring left behind, but by the quality or probable success of the offspring: reproductive fitness. Sexual selection is the expansion on the ability of organisms to differentiate each other at the species level, interspecies selection.

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Sexual selection - WikipediaClearly, preferential mating represents a selective force on a population - selection driven towards the preference in question. If females prefer males with bright plumage, males with bright plumage will be selected for and males without will be selected against. I don't know what an "evolutionary event" is, but clearly any influence that alters allele frequencies in a population over time is evolutionary. Things like HGT, or genetic drift, or mutation, alter those frequencies at random; forces such as natural selection and sexual selection alter those frequencies in response to environment (where "environment" includes other conspecifics).

A kind of selection is regarded as non-selective?This isn't an issue of semantics, Chiroptera. This is ol' Jocko not knowing sense from nonsense, as usual.

Right. That's because Hardy-Weinburg breaks down under selective conditions. The assumptions that underly H-W equilibrium are there because that's what you have to assume to take selection out of the picture. Sexual selection doesn't have anything to do with H-W equilibrium except for being one of the reasons that you'll never, ever find a population in H-W equlibrium in the real world.Sexual selection is when alleles increase or decrease depending on the attractiveness or fertility of their bearer. As such, it is clearly selective. Preferential mate choice causes differential reproductive success; therefore, clearly, mate preference constitutes a selective force.

Only because you have no idea what you're talking about when you say "Hardy-Weinburg equilibrium." I assure you that when they cover this concept in your classes, you'll see that there's no contradiction at all in what I just said.

Good point.

You got Brad McFalled!

You're not making any sense. "Operates on the changes"?Preferential mating alters allele frequencies in the direction of the preference; thus, it's a form of selection.If you're going to rebut this, you're going to have to bring something to the table that isn't your usual garbled nonsense. No, of course it is. If the preference of females is for bright feathers, then males that have drab plumage are selected against, and allele frequencies are driven towards bright plumage. If the preference of females is for the male who wins strength contests, then males who can't win such contests are selected against, and allele frequencies are driven towards weapons, like the large curling horns of mountain rams.Preferential mating is selection - sexual selection. No, it doesn't. Preferential mating is sexual selection.Edited by crashfrog, : No reason given.

You introduce an antibiotic into a lawn of E. coli. Resistant individuals live but nonresistant individuals die.How didn't those nonresistant individuals not just experience natural selection? That's the textbook example of natural selection operating on individuals.

Once again I've underestimated your enthusiasm for substituting glibness for actual debate. I apologize.

I haven't the foggiest notion what your remarks have to do with my example. Natural selection isn't death; it's when environment promotes differential reproduction of individuals because of traits they possess that make them better or worse adapted to conditions in that environment.The fact that all organisms die doesn't represent selection - simply because of how universal that is.As I said, selection for antibiotic resistance is the classic example of natural selection. Individuals with a resistant phenotype are selected for; individuals without that phenotype are selected against. A gene that has no effect on phenotype experiences no selection, by definition, because selection can only occur based on phenotype.

Do you have kids?

No, the genes are being inherited. The individuals are being selected based on phenotype. Genes that have no effect on phenotype experience no selection; this fact is sufficient to dispel notions that genes are selected. Right. Genes are inherited. Right. Through genes, which are the units of heredity. I'm not sure what the relevance of any biologist's "eminence" is, exactly. Individuals are selected; then their genes are inherited. The attributes they had that rendered them more or less adapted to their environment. Only because of their expression in the phenotype. If the genes were not expressed, they had no effect on selection.You can have the Super Mutant X gene, that gives you powers over metal or mental powers, or whatever; but if you also have the gene for, say, progeria, you're going to be selected against. Genes are not the units of selection because it's impossible for gene to be selected except as part and parcel of an organism's complete genetic content. An organism is only as "evolutionarily strong" as it's "weakest" gene, regardless of how great other genes might be - since an organism either passes on half or more of it's genes, or none at all.

Clearly they don't experience natural selection; you might say that they experience a sort of "gene selection." None of those figures are involved in this discussion, I notice, so I don't see the relevance of "eminence". I don't see how that question could be relevant without ascribing a telological purpose to evolution and selection.Things get selected for the reasons Darwin originally said - because a given population of organisms will, eventually, grow so large that their environment cannot sustain all of them; at that point, some organisms will reproduce and some will not. Some organisms will reproduce more and some will reproduce less. Statistically, which individuals do or don't will be affected by their adaptations to their environment.But to ascribe agency to genes, as you appear to be doing, is a fantasy. It's a metaphor gone too far; I notice people have a tendancy to do that to Dawkins' material. Often it's just "not die right now." Or, we might call it "making another individual." See, we can reword whatever we want to make either genes or individuals the focus of selection. How you get gene-focused selection out of that is still a mystery to me.

Fallacy of the looming caveat. The vast, vast majority of organisms on Earth, by number or by weight, are asexually-reproducing organisms.So I'm not sure it makes any sense at all to try to define the focus of natural selection based on the behavior of sexual organisms; such organisms are little more than a corner case in the grand scheme of things.