Is there more than one definition of natural selection?

Go back to the weebles example and you'll see how individuals are selected.

cf wrote: But where to the individuals go in the course of evolution when that are "naturally selected"? Through Door # 1 to lay down and have sex? Don't unworthy or undesirable individuals sometimes get to have sex, too? Please see my post to RADZ above in Message 240”HM

To cheap no-tell motels, to make with the boom-boom and get somebody preggers."Naturally selected" means "lived long enough to reproduce." Usually they don't live long enough. They die virgins. Or, a mate may reject an individual's sperm through various physical mechanisms. So it's possible in some species for an individual to inseminate a mate, yet still be naturally selected against when their sperm never has a chance to fertilize an ova. 240 is what I replied to, so obviously I did see it. Again, my weebles example addresses all your questions in regards to natural selection operating on individuals.

No! The "naturally un-selected" individuals often get to do that, too. Think about Rwanda. “Naturally selected” means that a population has experienced differential reproductive success. There are no NS agencies going around picking out individuals who qualify to have sex and then makes a bed for them; that's more like "sexual selection." NS, instead, is going around populations of individuals picking out alleles that are disproportionately favored when that population is undergoing differential reproductive success.”HM

Clearly not, if they were selected against. You mean, where all those children were killed long before they could possibly have mated and produced offspring of their own?That's kind of what I'm talking about, HM. The classic way that that differential success occurs is because some individuals have phenotypic traits that lead to their untimely death before they've had a chance to mate.The sexual selection way that occurs is less fatal; it's a matter of one individual obtaining mate access less successfully than his peers. Eventually, though, the result is the same - he dies having less offspring than his peers.Either way, it's happening to individuals, and having an effect on the population. Except that natural selection can't pick out one allele. You can only knock out one individual's alleles at a time, because natural selection operates on individuals.Why don't you get this, yet?Edited by crashfrog, : No reason given.

cf writes unwisely: If individual A is selected to mate with individual B and they successfully produce offspring, neither one of them, as individuals, will evolve by NS into their offspring. Of course you know that. What actually is selected and what actually evolves is that complex of alleles mixed together from individuals A and B, which in combination somehow succeed to make other successfully reproducing individuals. So, you see, individuals can only live their effemeral lives and die without ever experiencing the joy of evolution. They don't get to go to Darwinland. But their alleles might have that pleasure, if they are good enough.Please, once again: No individual can be selected by NS or evolve by NS because every single individual lives but one life.*I think RAZD is mostly right about phenotypes being selected by NS. And phenotypes mean genotypes, of course. NS works on those phenotype/genotype complexes, not on the individual carriers of them.It may be worth noting here that very few phenotypes are carried by individual gametes when they unite in fertilization. For this reason, I see genotypes and their alleles as the true loci of evolution by NS.”HM*Why don't you get this, yet?

....what? "Evolve into NS"?I see that we've passed the point where you can construct meaningful statements about biology. We hit it eventually, every time, it seems. For the third time, stated differently - some of those lives contain the production of more children than the lives of their peers. Some of those lives are long, with much mating. Some of those lives are too short to have mated at all.That's why natural selection operates on individuals - because individuals have lives of different length, with different amounts of reproduction occurring therein.Do you understand, now? Go back to the weebles. Right. And both phenotype and genotype are properties of individuals. Populations only contain different phenotypes and genotypes because they contain individuals with different phenotypes and genotypes, in the way that a milk crate can only hold milk because it's a holder for milk bottles. When they unite in fertilization, they contain only the one phenotype.

Ahhh, please read my words again. I never said "Evolve into NS."That's downright shabby! You ought to be whipped with a cane. Nah, I ain't goin' back there. I've been to the weebles. Done that. Now I'm going to TVeebles to watch pro football. Go Seahawks!”HM

Hrm, could have sworn. Weird.Well, fair enough. My bad. So we're agreed, then? NS selects among individuals?

[Seahawks...ugly. Booo!] That one goes into your permanent record. And it's not the first one, either! Without resorting to the weebles, I think it is fair to say that NS uses individual organisms as software stores, stocked with beneficial alleles, from which it makes its selection. Remember, individuals are not the ones that evolve. Individuals die early and become dirt. But their alleles, even without much phenotyplcal protection by haploid gamete cells, are the things that actually get selected by NS and survive an evolutionary event...and they survive their host organisms many, many times over.crash, what's the point of NS selecting an individual if it is certain that the individual will die? You're looking in the wrong place to find the survivability meaningful to evolution by NS. Evolution by NS happens when a population fixes new beneficial alleles in some significant way. Your individuals can be selected by each other to have sex, of course, but this is not the same thing as NS, this is only sexual selection. All any individual can do to participate in NS is to make gametes, have sex, and die. Meanwhile, down at the genome ranch, what is really being naturally selected are the beneficial alleles of a population.”HM

That's my point. What's selected are individuals. I was about to remind you of that, but that's what I've been getting at the whole time. Natural selection selects among individuals; populations experience changes as a result.Those changes are evolution. Agreed?So it still seems like "both" is the answer. We see the effects of natural selection on both individuals and populations. Having sex. That's the point. Getting to have sex.Not everybody lives long enough. Some individuals live long enough, but their sex is "fruitless", and it's the same as them never having had it.Populations are comprised of individuals who are alive. That's important to keep in mind. Whether an individual isn't alive because they were killed, or they're not alive because they were never born, is immaterial to natural selection; the end result of selection is that populations are restricted in terms of what individuals are alive at any one point. Selection is selection. That was certainly Darwin's point - that natural forces shape populations in precisely the same way that pigeon breeders do, by culling individuals and promoting certain matings or preventing others. It's instructive, sometimes, to identify differnet kinds of selection pressures, but that shouldn't make us lose sight of the fact that, ultimately, selection shapes populations by restricting the diversity of individuals.

crash, you are confusing sexual selection with NS. Sexual selection happens when there is disproportionate mating amongst individuals of a population. NS happens when there is differential reproductive success across individuals of a population. Nah. You're talking about sexual selection”differential mating success. That's not what NS is. And I can only see your individuals as perfunctory camels, carrying their allelic burdens to a marketing oasis, where their cargoes will be selected like dates for their usefulness and desirability.”HM

Since the first obviously results in the second, sexual selection is clearly a form of natural selection. Another form would be the predator selection I used in the example of the weebles, and another form would be the artificial selection of plant breeders and animal husbanders. But it's all natural selection. As long as you understand that the selector is the environment they live in - which includes the other members of their species - then I don't see your problem with that conception.

crash, I don't think you understand what NS really is. NS arises from the differential reproductive success amonsgt individuals across a population. Differential mating success may or may not leading to NS. There is no rule that requires sexual selection to lead to NS. They are two different things. Sexual selection may go on in a population without any NS occurring at all.btw: I wouldn't be too distracted by the word "natural" in NS. It was put there by Darwin to differentiate his theory from "supernatural selection," if you will, or otherwise "Creation."”HM

I know that. Differential reproductive success has many causes. One cause would be differences in survival, where some individuals simply don't live long enough to mate. Another cause would be human breeders selecting which individuals are allowed to reproduce and which are not.And yet another would be sexual selection, where the differential success in sexual organisms being able to attract mates results in a differential in the reproductive success between individuals.Sexual selection is a kind of natural selection, obviously. Even Darwin recognized this. It must; it's inescapable. Sexual individuals who have differential success in attracting mates must, by definition, also have differential success in reproducing. It takes two to tango. The peacock who can't ever get laid, obviously, is not going to produce as many offspring as the Wilt Chamberlain of peacocks. If selection is occurring, it's natural. I'm not distracted by it. It was simply Darwin's attempt to indicate that, like plant or animal breeders, environment itself selects which individuals leave more or less offspring - that it's not just random. The number of offspring an individual leaves behind is affected by its individual traits, its adaptation to environment and its attractiveness to mates (in a sexual species.)Again I find myself at the point where I have to ask you what you don't understand about what's going on, here. (Maybe you could go work on your boat for a while and think about what I've said. It might grow a little clearer.) Sexual selection is clearly one mode of natural selection. Everything you say only proves that that is so.