Talk:Natural selection/Archive 5

This is an archive of past discussions about Natural selection. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

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New version of Natural selection

Kim van der Linde and Gleng have developed a updated version of the Natural selection article at User:KimvdLinde/Natural selection. At the talk page there:

This page shows a proposed new version of the article on Natural Selection. This has been developed using parts of the existing version by Kim van der Linde and Gleng, following the discussions on the Natural selection talk page. We have tried to produce an article that will be both clear and rigorously accurate. If there is general agreement that this version is an improvement over the existing version, then we will replace it. Please put any comments and criticisms about this proposed new version on this Talk page, and in particular please indicate your support for, or opposition to, replacement of the existing version. Please do not edit this version except for any minor corrections at this stage.

Kim van der Linde ^{at venus} 05:16, 13 May 2006 (UTC)

I like the new version. Let's go with it. Guettarda 23:05, 13 May 2006 (UTC)

what is born out of spite...

"A well-known example of natural selection is the development of antibiotic resistance in microorganisms."

let's dissect the very first sentence above: "an example of selection is the development of antibiotic resistance..."

kim, i thought you agreed that selection is not evolution !? now the whole new article is full of such high-school-level imprecisions and sloppy formulations.

and, possibly more serious, the new article is mainly about evolution !

everybody should welcome additions and revisions to the existing article as long they are done orderly and carefully.

but one must correct any imprecisions, and one must refocus back to selection any additions that focus mainly on evolution.

note that i am an evolutionary biologist but i couldn't care less about selection for scientific reasons that are not simple.

however, the article about selection must be about selection, i.e. about the generation of fitness differences. Marcosantezana 04:23, 16 May 2006 (UTC)

See User_talk:KimvdLinde/Natural_selection#what_is_born_out_of_spite... for responses. Kim van der Linde ^{at venus} 20:46, 19 May 2006 (UTC)

Axel147 on new KimvdLinde version

I generally like it!! Here are some hopefully constructive comments...

I think the example is given too much prominence and is a bit scary for the layman.
On Sober's distinction the emphasis should be 'cause of selection' vs. 'free rider' (not trait vs. individual).
I think I object to the sentence 'For Darwin, fitness was equivalent to survival'. Darwin did not really use the term 'fitness' obviously undertood the importance of fecundity so I think this is misleading. ('Fittest' is really Spencers.) And is it survival of individuals or families of indiviuals etc.?
The article descibes natural selection in different places as a 'process', 'principle' and an 'idea'. Is this consistent?
The wider defintion is also a 'mechanistic' one: it is just that the mechanism of selection is combined with a mechanism for propagation (inheritance).
I hadn't read Petri Krohn trivia up until now! If only Darwin had used the term 'natural preservation' we wouldn't have had the mass discussions on this page! I'm not so sure this is trivial though as this confirms (if there was any doubt) that Darwin meant natural selection in the wide sense. However 'preservation' is not quite synonymous with 'evolution by natural selection'. New variation is required for (substantial) evolution but not for preservation. So let's get this part right!

— Axel147 19:55, 18 May 2006 (UTC)

I don't think KimvdLinde's point about 'result' quite makes sense: probable survival and reproduction of an individual is the result in KimvdLinde's 'phenotypic selection'. This is not fundamentally different from Darwin's probable preservation of favourable traits as the result of his 'natural preservation'.

(In any case it seems to me to be perfectly legitimate to define a process using a result: scoring a goal, boiling a liquid, lighting a match...)

— Axel147 13:00, 19 May 2006 (UTC)

The examples you give are perfect examples of a process, and that is exactly what the mechanistic version of NatSel does. As in scoring a goal, the ball is not part of the scoring, it is an object used to do the action with, resulting in a result (ball is in the goal). If you would include the ball in the mechanism, scoring a goal with for example a ice hockey puck should have its own name, just as scoring a goal with a discus. Kim van der Linde ^{at venus} 14:16, 19 May 2006 (UTC)

In your world the phenotype is the object used to do the action with, with a result (phenotype is selected). But you haven't answered my point: both defintions can be said to be mechanistic, and can be undertood in terms of a (probable) result. It is false to claim otherwise. — Axel147 15:22, 19 May 2006 (UTC)

You are right, the second has a mechanistic component in it. What would be your preferred choice of labeling those two definitions? Kim van der Linde ^{at venus} 15:30, 19 May 2006 (UTC)

It's difficult. Endler tries 'restricted' and 'general' but restricted sounds a bit pejorative. The only thing I can think of are more neutral words like 'phenotypic', 'wide', 'expanded', 'extended', 'general', 'broad','classic'. (Less sure about 'narrow', 'Darwin's') — Axel147 16:10, 19 May 2006 (UTC)

'Restricted' and 'general' contains a POV, so the words need to be neutral. The reason to use the current terms is that the inclusive version includes the result as wellas the mechanistic part. The mechanistic def describes what it is, just the mechanism. I think the terms should be clear about this. But I will leave it as it is untill there is a better set of neutral terms. Kim van der Linde ^{at venus} 17:22, 19 May 2006 (UTC)

What is it that causes a phenotype to be selected?

Natural selection we are told in the opening sentence is a 'process'. The beginning of the process, presumably, is the point of conception and the end, presumably, is the point at which an individual ceases to have any influence on its descendents (which could even be after death).

But it is imperative we define what it means to be a 'selected' phenotype. Is it defined in terms of capacity to survive and reproduce? Absolutely not — it is defined in terms of its capacity to propagate its characteristics. This is the only thing that matters. It is the only viable definition: and it demands a mechanism for propagation to be part of the definition of natural selection despite objections from KimvdLinde.

It is totally false to imply natural selection can happen without inheritance. If anyone can argue otherwise please do so. I think the article is a failure if we do not clearly define the criterion for selection.

I have since retracted the above!

— Axel147 04:23, 20 May 2006 (UTC)

It is totally false to imply natural selection can happen without inheritance. people try to artificially select for stuff that has zero heritability all the time. My understanding is that hip dysplasia has a heritability not significantly higher than zero in many dog breeds, but breeders still try to breed it out. The Alberta Eugenics Board sterilized citizens of my Province until the 1970s, they were trying to breed out traits with zero heritability. Both of these examples still constitute artificial selection despite there being no heritability. By analogy, traits with zero heritability may still determine which individuals get to breed, by Natural Selection. I've provided you with this argument before, I don't remember what your response was, feel free to just point me to the diff. Pete.Hurd 04:44, 20 May 2006 (UTC)

I am sorry Axel that you feel that this article uses the wrong definition. The only thing I can do is to suggest to you that you write an scientific article about it for a scientific journal and convince the scientific community. See for example Futuyma, D.J. 2005. Evolution. Sinauer Associates, Inc., Sunderland, Massachusettes, page 251. I quote: It (=natural selection) is a name for statistical differences in reproductive success among genes, organisms, or populations, and nothng more.. Or I can send you the article (pdf) of Lande, R. & Arnold, S.J. 1983. The Measurement of Selection on Correlated Characters. Evolution 37: 1210-1226, the key article concerning this topic. A screenshot of the crucial paragraph can be found here (Probably good as fair use for me as limited use, not for wikipedia). The article is cited 1277 times (!!!!!), primarily for this clear distinction. If you want to start a discussion with Russ (Lande), I have the e-mail address of him for you. Kim van der Linde ^{at venus} 04:50, 20 May 2006 (UTC)

I reverted the proposed changes by Axel, because the distinction had become a distinction between natural selection perse and evolution by means of natural selection.

Scientists use several, slightly different definitions of natural selection; the main difference is whether natural selection is viewed as the selection of phenotypes in a single generation or the selection of traits over several generations.

Selection continued over multiple generations is evolution, not Natural Selection. This is a key distinction between the two. Kim van der Linde ^{at venus} 04:59, 20 May 2006 (UTC)

I absolutely agree with Kim on this, and this is not a minor issue. To confuse a mechanism (natural selection) with its consequence (evolution) is to destroy the explanatory power of the mechanism; the "explanation" becomes tautological and vacuous, and the criticisms of creationists gain some validity. The power of the explanation lies in the simplicity, inevitability and "blindness" of natural selection as a mechanism. most importantly here, the mechanism (selection) has no ability to "tell" whether a trait is heritable or not. natural selection will act anyway. There will be consequences whether the trait is heritable or not, consequences that will affect evolution, but adaptive evolution of particular favored traits will only occur if the traits have a heritable component. Gleng 10:36, 20 May 2006 (UTC) In the opening sentence, "the process" could be replaced by "all the mechanisms by which", but I'm not sure that this would be an improvement in clarity.Gleng 10:39, 20 May 2006 (UTC)

In the end, Natural Selection is such a simple concept, that it becomes difficult to grasp. Because what it does is just giving the maladapted a hard time so that the better adapted produce more offspring. The rest is details on sub-mechanisms based on live stage, context, selection agent etc. Kim van der Linde ^{at venus} 15:13, 20 May 2006 (UTC)

Ok, I am forced to retract what I said yestersay as today I seem unable to defend it. I accept natural selection in the phenotypic sense can be both measured and defined 'without recourse to principles of heredity'. Of course selection always happens 'blindly' - I never meant to imply otherwise. In the Darwinian sense inheritance is only required to achieve preservation of variations.

The only case where 'capacity to survive and reproduce' differs from 'capacity to propagate characteristics' I think is with the green beard effect. A green beard may have good capacity to secure its characterisitcs in future generations despite low fitness. But even in this case I accept it is the fittest who are selected (and the descendents of those with the greatest inclusive fitness who survive). And I accept also that fitness can be defined without reference to genes.

Despite all this KimvdLinde's 2 extracts appear to contradict each other: how 'natural selection is statistical differences in reproductive success among genes' is compatible with 'natural selection acts on phenotypes, regardless of their genetic basis' I am not sure? I think the answer is that the second defintion goes out of its way to call itself 'phenotypic selection' and 'phenotypic natural selection' while the first leaves the door open to the extended definition.

The two are within the same scope. The key is difference is the Unit of selection. The first quote includes various levels, while the second was from an article that primarily dealt with whole individuals as the unit of selection, and for that reason used phenotypic. However, you can talk in the same way about it when discussing meiotic drive.Kim van der Linde ^{at venus} 00:48, 21 May 2006 (UTC)

(Continued)Anyway as a thought experiment I would like you to imagine for a moment that the principle of inheritance no longer exists: let's say that individuals still have a genetic basis, and that basis still influences their liklihood of reproducing. But here is the difference: in this world the children's genes have no relationship with those of the parent: we can imagine them to be chosen at random. The question is would natural selection still exist? Well in a Darwinian sense no, because there is no way of preserving particular variations. But in a phenotypic sense yes, and fitness would also continue to exist.

Exactly, it would still exist, the difference is whether it has an effect towards the next generation. Kim van der Linde ^{at venus} 00:48, 21 May 2006 (UTC)

(Continued)In answer to Gleng one of my main reasons for joining this discussion is with hope of adding to an article that would clearly express what Darwin intended, so as to counter creationist objections. I understood the argument and think the problem wouldn't exist if Darwin as he later wished had used the term Natural Preservation.

I think one of the manin faults of the scientists is that they get dragged into the discussion with creationists about Darwinism. We are 150 years ahead, and the current science is so much more sophisticated. It actually caters them because it is much easier to shoot holes into Darwinism than in the current thinking of Natural Selection. Furthermore, wikipedia is an encyclopedia, and it should reflect what we know. It is not a soapbox, nor has it an agenda. If an accurate description of an topic results in ammunition for a certain group, so be it. Kim van der Linde ^{at venus} 00:48, 21 May 2006 (UTC)

(Continued)In the current article we have an opening sentence 'Natural selection is the process by which individual organisms with favorable traits are more likely to survive and reproduce' . But if favourable traits are those which help an organism survive and reproduce it is this defintion which seems tautological. Darwin's 'preservation of variations' is much more substantial. Phenotypic natural selection therefore, not Darwinian natural selection is surely the one which is more easily reduced to tautology (see Endler). However the argument for evolution stays the same: all we are debating is whether inheritance falls inside natural selection of outside of it. The potential tautology just sits in a different place.

— Axel147 20:32, 20 May 2006 (UTC)

It may look like a tautology but those can be found by removing pieces of the sentence as they are redundant. So, if this sentence is tautological, we could remove the word: Natural selection is the process by which individual organisms with traits are more likely to survive and reproduce. This first version does bot mean anything anymore. The second version not even produces a coherent sentence. And you are correct, most of the discussion we had was about whether NatSel was evolution or not. Kim van der Linde ^{at venus} 00:48, 21 May 2006 (UTC)

To be consistent please correct sentence 'Natural selection need not apply only to biological organisms; in theory, it can be applied to any system in which entities 'reproduce' in a way that includes both inheritance and variation.' — Axel147 22:45, 20 May 2006 (UTC)

When I was at university I developed a genetic algorithm.

Generate a population of phenotypes ('best fit curves' for a quantum mechanical problem) from genes (input parameters).
Select phentotypes to reproduce using a fitness criterion
Reproduce (with inheritance by shuffling groups of genes of selected phenotypes)
Add variation (micro and macro mutations)

If step 2 is 'natural selection' I would say it is impossible that step alone can create complexity? — Axel147 09:55, 21 May 2006 (UTC)

Indeed, Natural selection on its own can not generate complexity. If the complexity is associated with higher fitness, those more complex individuals will be selected for. However, if the highest fitness is achieved by simplification, those will be selected for. You could have programmed that in to your genetic algoritm (I love them), and the result would be simplification, which for design purposes can be very usefull fitness criterion. The whole algoritm that you described is evolution by means of natural selection. Kim van der Linde ^{at venus} 14:38, 21 May 2006 (UTC)

My point was why did you put in the artice whether 'natural selection per se can generate complexity is strongly contested'. Surely selection (step 2) on its own cannot generate anything. Only in the extended sense (step 2 + 3) is there even a debate? — Axel147 17:04, 21 May 2006 (UTC)

Missed it, this section was copied from the old version,a nd although I have read over it, it has not endured the same scrutiny as the new sections that I wrote above. I will in the coming days look more into the isue, and I think I will rewrite it somewhat. The claim that NatSelEvol can not generate complexity is a creationist one, in biology, there is not an issue about that. Kim van der Linde ^{at venus} 17:20, 21 May 2006 (UTC)

In response to Gleng. I think we are on agreement with this (and apologies for giving a now retracted false argument for inheritance which appeared to show I was confused over the mechansism). Whhat I intended to say is that I think it is important to understand that the use of words has changed but the explanatory power has not. When Darwin says natural selection is [to paraphrase] 'the selection and preservation of variations which result from selection of the best adapted individuals' this does not undermine the explanatory role of phenotypic selection which is part of this process. (Nor is this equivalent to evolution as there is no mention of new variation.) There is no confusion over the mechanism (despite my strange contribution a couple of days ago!). It is just a question of semantics. — Axel147 09:55, 21 May 2006 (UTC)

I'm sure we are in agreement, and just struggling with the right words. I think though that it is easy to forget how important non heritable variations are for individual fitness. Most of the things that make individuals differ are differences of environment (whether involving interactions with genes or not), or are the results of chance and circumstance, or are acquired characteristics. These determine traits as we understand them much more than differences in genes, the effects of which will be more subtle and more widespread (each gene affects many traits, mostly in slight ways). It's still a bold idea that natural selection of individuals for these traits as a whole, but resulting in selective preservation and recombination of just the genetic components, can have such power.The argument is far from tautological, and the conclusions far from inevitable - the mechanism might be inevitable but the consequences still take a leap in vision to encompass the vast time, the large populations, and the effects of random change. Darwin grasped this vision, but he saw the big picture only - the devil in the details means that we are struggling with words and concepts whose meaning has shifted as the importance of the nuances has become clearer. Reading Darwin now, he is not wholly consistent and coherent in his usage; he was a thinker, not a preacher, and thinking is a process of continual change of meaning :) Gleng 12:40, 21 May 2006 (UTC)

In the Wikipedia evolution article I think we should clarify the sentence 'Natural selection is the idea that individual organisms which possess genetic variations giving them advantageous heritable traits are more likely to survive and reproduce and, in doing so, to increase the frequency of such traits in subsequent generations.' The is good description of Darwinian natural selection but we should more clearly distinguish this from phenotypic natural selection otherwise people will be confused. — Axel147 09:55, 21 May 2006 (UTC).

I had seen that sentence, and I am going to poke the editors there in some time. Currently I am focussing for a small time on less contentious articles (parrot species and systematics), but when I am in the mood, I will start talking there also. Kim van der Linde ^{at venus} 14:38, 21 May 2006 (UTC)

HIStory

Yo! Can we dump the history and sociology stuff from this article? It heavily retreads stuff that happens in evolution, and I think, as a secondary page, it doesn't really belong here. Brief mention of it and reference to better, secondary articles on the subject are in order, but not the 4-5 odd pages we've got here. I humbly submit. Anyone concur? Graft 23:24, 21 May 2006 (UTC)

Well dumping it completely no, but cutting out significant sections, fine with me. That are oieces that are left of the old article, I did not want to rewrite everything at once. Kim van der Linde ^{at venus} 01:16, 22 May 2006 (UTC)

Looking at the History and Impact sections here and in evolution I would say they are generally focussed on Natural selection here and on evolution there. There are two issues - the impact of the idea of Descent of species (covered in evolution - and the impact of the explanatory power of the mechanism, covered here. I don't know that an article on Natural selection can avoid either the history or discussing the very broad impact beyond biologyGleng 08:37, 22 May 2006 (UTC)

general comment

I want to thank all the people who have been active on this article over the past couple of weeks - I am commenting on the process, not the article itself - I think this has been a model of collaboration for writing Wikipedia articles. bravo! Slrubenstein | Talk 11:01, 22 May 2006 (UTC)

adaptation

"this can lead to adaptation" - I think this needs explanations. Most non-scientists think adaptation is an intentional act; I think in evolutionary biology it is an effect, not an act. "Adapt" is a verb and it is hard to think of it as anything other than an act, the act of the creature thad adapts (i.e. not the act of "nature"). Slrubenstein | Talk 11:04, 22 May 2006 (UTC)

I tweaked it a bit, and I think it is clearer now. Kim van der Linde ^{at venus} 11:21, 22 May 2006 (UTC)

Thanks. Now, please look at my latest edit to the article. My fear is that I am being redundant. My concern is to be crystal clear about adaptations being (1) inherited rather than learned and (2) effects rather than acts. I think the whole article is consistent with this view, but I also think these two distinctions are what trip up almost all non-scientists and even many scientists, so I think the two distinctions need to be highlighted and explained very clearly. Right now, they are explained in the context of a larger narrative about the development of the theory. There is nothing wrong with this narrative, I just fear non-scientists will fail to appreciate these subtle and counterintuitive distinctions. I invite Kim, Gleng, Graft, Axel, others to address this in the article. Slrubenstein | Talk 12:51, 22 May 2006 (UTC)

The way you have added it is actually causing more cinfusion, as this implies that adaptaitons are behaviour, which they are not perse. I will undo it for the moment, and add something to clarify it there as well later when I am back from workKim van der Linde ^{at venus} 13:02, 22 May 2006 (UTC)

That's fine - as long as you understand my point, then, if we agree, I am fine for you to figure out an effective way to communicate the point in the article, if you are willing, Slrubenstein | Talk 13:06, 22 May 2006 (UTC)

I think I will add a sentense making explicite what adaptation is in this context, more like a defining sentence. Or something like that. It is perfect clear what you want to say, and it is indeed one of those little nifty things that need to be addressed.-- Kim van der Linde ^{at venus} 13:09, 22 May 2006 (UTC)

I tweaked it, let me now if it is clear enough now. -- Kim van der Linde ^{at venus} 13:27, 22 May 2006 (UTC)

Kim, first, I re-indented this section - I think as long as it is just the two of us we should each be intented uniformly - otherwise, the text will get more and more cramped (and I think this indentation serves to make it clear who says what). I do not think your recent edit is enough ... but I am not impatient and can wait to see what others come up with. I want to stress that I do not think anything in the article is in any way "wrong." My concern comes only from my experience with non-scientists - undergraduate students mostly in the US but now in the UK, but also well-educated professionals, who really just don't get it. I think the language you use (including "passive") is correct and anyone with a good solid understanding of evolutionary theory will understand exactly what you mean and why it is important. I just think most lay-people will miss it. What is at stake here is not the accuracy of the article or even the clarity, as such, but who our audience is. If I asked an undergraduate student to read this article and prepare for a quiz, I am sure the student would read it carefully, memorize much of it, and be able to regurgitate it. But if I asked them to then talk about where new species come from, or ask them what makes Darwinian thought so radical, I'd discover that they just didn't get the distinctions I make above. Is this important? I think so, given how many students increasingly turn to Wikipedia, and given the popularity of creationism in the US which is tied to the abysmal standard of science education we have. But I do not expect you or other people contributing here necessarily to agree with me on this point - my point not about natural selection but about our target audience. So does the article really need more work in this regard? I think so but am happy to see what others think, if you or anyone else think it is worth the effort or see elegant waysa to address this. Slrubenstein | Talk 13:49, 22 May 2006 (UTC)

If I am correct, the question you ask is about the scope of the article. I do not think that this article should detail speciation for example, there are a whole series of other articles about that on wikipedia. In the end, Natural selection perse is pretty dull. It is the embedding in the wider context that makes it so radical. Darwins idea was so radical because he explained evolution by means of natural selection. And maybe that is what we need, a seperate article about Evolution by means of Natural Selection (which might be actually already covered enough in Darwinism and evolution). What I question to a degree is how far we have to go in making each and every article creationist proof (it actually annoys me at times to see that some American controversies creep into every possible article that is even slightly related to it). Maybe we can do a littlebit here and there to clarify and point towards the appropriate articles, but in the end, I think we should keep the article as much as possible on the topic, and leave all the social controversies out of it. Just my 0.02 Euro cents. -- Kim van der Linde ^{at venus} 14:30, 22 May 2006 (UTC)

Fair enough! But just to be clear, I didn't mean that we should explicitly discuss creationism or any creationist objection (which we do in the evolution article) or go into detail on speciation - only highlight and explain the two distinctions I draw concerning adaptation. (My comments about creationists were only meant to explain why I feel strongly about being so clear about adaptation, not to spell out more turf the article should cover). Let's see what others think. Slrubenstein | Talk 14:58, 22 May 2006 (UTC)

I understand Slrubenstein's concern, but I think it's difficult to avoid using the word 'adapt' in some form or another. I can't think of anything better than Kim's wording at the moment. I think like Kim we could go too far in making the article creationist proof, but equally we could go too far in making it read like a science text. The audience for an encyclopedia no doubt includes many lay people particularly for an article with such great general interest as this. Ensuring the article accessible to non-scientists is surely a worthy goal if it can be done without compromising it. Hopefully that should also help in making it creationist proof. — Axel147 18:22, 22 May 2006 (UTC)

If it is a problem with the language that is near-impossible to avoid, perhaps the only solution is to explain (as concisely as possible) what we mean by "adapt" (i.e., adaptations are inherited not learned, and the effect of natural selection and not the cause) in any article on evolution or some aspect of evolutionary theory (in other words, I am suggesting the link to the adapt article is not enough, we need a very brief definition/explanation even here). Just my own GBP .02 (and remember, this is worth more than a USD .02!) Slrubenstein | Talk 09:48, 24 May 2006 (UTC)

Did I get lucky with Endler?

Forgive me for presenting this topic once more but I do have a bit have a bit more evidence - so please bear with me. And this is related to the scope question, whether a separate 'evolution by natural selection' would still be useful and also the creationist proofing.

First let me say I welcome the paragraph on definition in the new version but just think it might go a little further. Kim's view that 'natural selection per se is pretty dull' and that it is the 'embedding in the wider context that makes it so radical' is of course perfectly coherent. The problem is that is true only when using a phenotypic definition while many scientists and creationists are using a wider one.

No, because Natural selection is a single generation thing regardless of definition, and what is interesting is the multigeneration thing where you get speciation by a passive process and do not need a God. -- Kim van der Linde ^{at venus} 14:41, 23 May 2006 (UTC)

Once we have included inheritance, we have the full mechanism, the full life cycle so that is enough for difference in trait frequency. — Axel147

Depends on your defintion. -- Kim van der Linde ^{at venus} 01:20, 24 May 2006 (UTC)

The crux of the difference on the definition issue is heritability and depending on one's taste (and wideness of definition) we know the role played by inheritance can be either:

A pre-requisite for or part of the mechanism of natural selection
Only required for natural selection to be 'effective' or to achieve 'results'

With the first it's important to realise the mechanism is split into the 2 separate parts of i) blind selection followed by ii) inheritance.

We also know that these equate to what I have been calling 'Darwinian natural selection' and 'phenotypic natural selection'. And that there is no difference in understanding, in overall mechanism, merely in semantics, but it is still important to make this clear.

So are both definitions equally in play? Can we get rid of one? Well as a representative of the layman (and without easy access to scientific literature) I have to conclude the answer is 'no'. Let's for instance have a quick look at using the views of three eminent professors Sober, Futuyma and Dawkins.

Starting with Sober, he is clearly using the phenotypic definition. In 'The Nature of Selection' he tells us 'natural selection does not explain why I have an opposable thumb. This fact falls under the purview of mechanism of inheritance.' That is reasoanable enough. It implies, in the phenotypic sense, natural selection by itself cannot achieve or explain adaptation.

So when Futuyma says (in his interview linked to the article) ' Natural selection is the process by which species adapt to their environment. A mechanism of evolution ' he seems to be using a wider definition.

No, he is saying that NatSel is PART of evolution. Besides that, we do not distinguish every detail all the time, and speaking language is not nessecarily reflecting always the underlying details how we actually deal with it. -- Kim van der Linde ^{at venus} 14:41, 23 May 2006 (UTC)

It is difficult to square his 'a process by which species adapt' with your view that 'NatSel by itself is pretty dull' — Axel147 17:59, 23 May 2006 (UTC)

If you equate NatSel with adaptation, you are right. -- Kim van der Linde ^{at venus} 01:20, 24 May 2006 (UTC)

Dawkins on the other hand is unequivocal in his use of the wider Darwinian definition. He explicitly makes the point in this quote:

'Turning from the fact of evolution to the less secure theory of its mechanism, natural selection, the mechanism that Darwin and Wallace suggested, amounts to the nonrandom survival of randomly varying hereditary characteristics. ' [1]

As explained within evolution context, not as a mechanism by itself.-- Kim van der Linde ^{at venus} 14:41, 23 May 2006 (UTC)

And you can hear him address the exact point on heredity here.

Just to show this position is very prevalent here are 10 serious links which explicitly make reference to heritability as part of the definition:

I agree that some of these positions are difficult to separate from 'evolution by natural selection'. But I think the point is that evolution is the outcome and natural selection is the full mechanism including inheritance. (As I have mentioned before a possible distinction suggested by Endler is that evolution requires new variation whereas natural selection requires only initial variety.)

I think one of the problems here is that nearly all definitions of natural selection use the word 'reproduction'. And the mechanisms for reproduction and inheritance are equivalent, though the two are conceptually different. As a result if often unclear whether an author intends the role of inheritance to be read as 1 or 2. While other authors deliberately avoid the debate by never unbundling the phrase 'evolution by natural selection'.

I think here you go seriously wrong with your train of though. The mechanisms are not only conceptually different. Reproduction is a way of passing the inhertitable information on to the next generation. Dividing the cell, as bacteria do is another way of passing it on (basically a variant of reproduction, but without sex). Other ways of passing this on what we would call horizontal gene transfer, which happens a lot in plants and is caused by virusses transported by insects. Furthermore, if a trait is not heritable (See for example the article abiout DES and reproductive issues related to usage of the hormone during pregnacies DES), offspring is often seriously maladapted to reproduce. However, when they reproduce, they do not pass this on to he next generation because it is not heritable, but in the mean while, natural selection has eliminated part of the DES population because they are incapable to reproduce. In this example, non-heritable variation, NatSel and reproduction come together, and as you can see, all three have their own place in the story and are not equivalent at places. -- Kim van der Linde ^{at venus} 14:41, 23 May 2006 (UTC)

This is not the crux of the argument. I am just trying to give a bit of background as to the origin of the differences. But in any case I think you are missing the point here: reproduction always results in inheritance of some of the characteristics. (Even if some characteristics can transfer by another mechanism this does not invalidate the argument as fitness is defined with respect to reproduction) — Axel147 18:14, 23 May 2006 (UTC)

Sorry, reproduction ~~does not result in~~is not equivalent to inheritance. -- Kim van der Linde ^{at venus} 01:20, 24 May 2006 (UTC)

Oh yes it does. Surely inheritance is 'the process of genetic transmission of characteristics from parents to offspring'. It is not possible to have an offspring with no relationship to a parent. — Axel147 07:12, 24 May 2006 (UTC)

Yes, it is that. To be honest, I find it sometimes difficult to follow what you want to say, and which point you want to make (echoing graft's remark). The general sweeping statement is correct, yes, most characteristics do have a (small) heritable component which is passed on to its offspring. However, not all phenotypic variation is heritable, and in fact, MOST variation in natural populations is generally not heritable (environmental, dominance, epistasis, maternal effects, GxE, etc effects are all not heritable). My last response was incorrect, what I intended to say is that reproduction is not equivalent to inheritance, reproduction leads to inheritance of the heritable component of the characteristics of the parents. -- Kim van der Linde ^{at venus} 13:17, 24 May 2006 (UTC)

In my original argument I say the two are conceptually different. I did not make any general sweeping statement about whether a small or large proportation of charracteristics are heritable: this makes no difference to the point. In terms of being difficult to follow it's probably becuase the original argument is hacked up so much! — Axel147 15:53, 24 May 2006 (UTC)

It was me than who misinterpreted this: And the mechanisms for reproduction and inheritance are equivalent. Anyway, glad we have solved this issue. I will be more carefull in responding, my appologies. -- Kim van der Linde ^{at venus} 16:11, 24 May 2006 (UTC)

Another is that natural selection is often used as a kind of short or long hand. Darwin's 'preservation of favourable variations' is succinct enough but Darwin might be guilty of this himself in other parts of his text. In the evolutionary narrative, whether directly or indirectly, it is both individuals and characteristics that end up being selected.

Those who prefer the phenotypic view seem at pains to separate selection from its consequences: to emphasise its 'blindness'. Those who take wider view seem equally at pains to identify natural selection with the full idea: not just the existence of differential reproduction but the observation that this results in a change in trait frequencies. Many people do seem on the fence (either accidentally or purposefully). But the end point of 'evolution by natural selection' remains the same, so does the understanding and so does the mechanism. And in this sense this is an empty debate.

'We must not lose sight of the distinction between natural selection and evolution by natural selection. There may be selection for a trait without that trait's increasing frquency. That will happen if the trait has zero heritability.' Sober.

True, but nor should we lose sight of the difference in the uses of the term natural selection.

With respect to this article I think we can do a little more to make the distinction clearer. It could even be said that in preferring the phenotypic definition but giving us an example of 'evolution by natural selection' this article is adding to the confusion!

(Please add comments at the end) — Axel147 08:29, 23 May 2006 (UTC)

As I said, NatSel by itself is pretty dull; effectivly: you take a population, apply some mechanism of eliminating the maladapted and you have a selected population. That is all. Then there is a lot of mechanistic stuff we can talk about. The main problem is that NatSel is best understood by its consequences, and that is why the example includes the effect over time. I would be perfectly fine with eliminating that, but I think that it become less readable, and less understandable. I think it is not wise to spend to much time on digging in deeper on the definition issue. This is promarily an academic issue, an important one, but not the main thing of the article. I rather focus on the rst of the text and get that as clear as possible to explain the details of mechanisms of NatSel.

You have to keep in mind, that the way people talk about NatSel is in the general way, as in Evolution by NatSel. It is an easy shorthand. It is when you get to the details when it start to differentiate. For that reason, EvolNatSel will win the popularity contest with NatSel. Try to step back from your own preferred views, and look at the wider context. Look at what is actually the aim of Wikipedia, and loo at the other articles that are out here. The aim is to bring the state of the art, not what popularity polls suggest. Cut through the normal speak and see what is there underlying at the science basis. -- Kim van der Linde ^{at venus} 14:41, 23 May 2006 (UTC)

There is nothing particularly state-of-the-art about the phenotypic definition. Why don't you take a step back from your own preferred views. I have tried to present both positions in a balanced way. Both definitons give the same understanding. By saying 'NatSel' is this or that and persistnetly using the phenotypic selection which you have accepted as being different from Darwin, Dawkins, Endler etc. I think you're the one being dogmatic. — Axel147 17:41, 23 May 2006 (UTC)

I agree with Kim, here. Selection without heritability is not worth discussing. Yes, there's "selection" against "individuals who smoke", "individuals who ate lead paint", "individuals who got hit on the head with a really big rock". But, without heritability it's simply not interesting. And there's no way to discuss fitness without heritability, so I think we should ignore the issue entirely and stick to heritable traits.

Also, I note that we have no discussion of selection coefficients, which we ought to very early on, methinks. Graft 16:38, 23 May 2006 (UTC)

Well, I find the mechanisms themselves also interesting, but I agree with you, most of the realinteresting stuff is about the effects of natural selection on the underlying genetics. And maybe we have to split the current mechanism section into two, of which one is about the signature of NatSel on the genetics. I will play around with that a bit. I disagree with you about selection coefficient at the beginning, but I will play around with them and see where they make sense. -- Kim van der Linde ^{at venus} 01:20, 24 May 2006 (UTC)

I think Graft is more or less agreeing with me. But in case it's not clear in the wider definition 'selection' is not the same as 'natural selection'. Kim and I agree it's important to separate selection from its results. We also agree that if there was no inheritance whatsoever the whole thing would be a waste of time. And we also both agree there is more than one definition of natural selection. We just disagree on which should take the lead. — Axel147 17:41, 23 May 2006 (UTC)

Okay, now I'm not sure who I agree with, because this debate is kind of rambling. Can you concisely state what the issue is? I'm wholly unaware of an important distinction between 'selection' and 'natural selection' (excepting the fact that the former might also include artificial selection). Graft 19:51, 23 May 2006 (UTC)

The debate put simply is whether natural selection is this or selection due to fitness differences (differential reproduction). — Axel147 21:22, 23 May 2006 (UTC)

Well, I'm assuming you don't give a shit about variation, since that's merely a presupposition; selection is predicated on the existence of variation, so in its absence it obviously can't occur. So your beef is only with including heredity in there, i.e., does selection occur in the absence of heredity? I think this distinction amounts to, at best, a parenthetical, and I don't we shouldn't waste time with abstruse questions of usage. You're not going to achieve a consensus on this based on vernacular or even scientific usage, because I don't think there is any such consensus. Perhaps selection only represents differential reproduction (as in, attempting to select for traits with zero heritability), or perhaps it represents the outcome of differential reproduction. That is, selection has occured when something is selected for. I think you'll find this varies depending on circumstance. Does this really strike you as a major and important distinction to be made? And if so, why? Graft 22:41, 23 May 2006 (UTC)

Graft, what you see as Natural selection is only one of the definitions, and I would say that the one you use is the genetical theory of natural selection. There are good arguments for other definitions and they are also widely used (see for example Futuyma's book, or the ground breaking article of Lande and Arnold). What I have tried is to write it such that it avoids as much as possible those definitional questions.-- Kim van der Linde ^{at venus} 01:13, 24 May 2006 (UTC)

What we are debating is a subtlety. But the reason it is so important it that Darwin's radical idea which explains adaptive evolution is either natural selection itself or something which sits alongside it. Surely whether natural selection is one of the greatest scientific ideas in history or 'by itself pretty dull' matters! — Axel147 07:33, 24 May 2006 (UTC)

Darwin's radical idea was Evolution by means of Natural Selection and the fact that evolution did not need the hand of an Creator but a rather dull and simple mechanism. -- Kim van der Linde ^{at venus} 13:17, 24 May 2006 (UTC)

Just a couple of comments here, coming back to the following " Selection without heritability is not worth discussing...But, without heritability it's simply not interesting. And there's no way to discuss fitness without heritability" There's a temptation creeping in here to overstate genetic determination. Fitness is defined without reference to heritability and doesn't have very much to do with it. Selection is inevitably mostly of individuals for traits that may not be heritable or have only a slight heritable component. Now selection of heritable components of traits have consequences clearly foreseeable - you might class these as interesting therefore, and they are. But selection for non heritable traits also has consequences, including for evolution. This encompasses a huge range of things - founder effects are a result of selection of individuals for traits (the property of being in the right place at the right time) that do not have a genetic basis; prenatal and neotatal environment have massive effects on phenotype and are in some senses inherited. Inheritance in the sense that most people will understand it is about wills and money. So what's my point? Don't overstate the genetic basis. It's not true that most traits have a simple genetic basis; natural selection is blind and "noisy", it's seldom a clean knife. The strength of the idea is not that natural selection is this intelligent, designing force, but that it is anything but. It's simple, crude, blind, and only a part of what is selected will make any difference in the long run (and other things might make more difference in the short term). Yet, given enough time, enough variation .... Pulling evolution into the definition of natural selection makes it much less interesting in my book, and much less powerful as an ideaGleng 09:00, 24 May 2006 (UTC)

Founder effects are precisely NOT the product of selection. That's simply an extreme population bottleneck. That's not selection.

As to the genetic basis, sure, many traits don't have a simple genetic basis, or even any genetic basis at all. But, as I think Kim is saying, it means precisely dick outside of the context of evolution, i.e. in the absence of heritability. What is it's power in that context? What makes it worth discussing in detail? Graft 14:31, 24 May 2006 (UTC)

I personally think it is worth a lot, because to study the mechanisms of Natural selection you do not need to know the heritability and to speak with Russ Lande, see here, it is interesting to know what happens at the phenotypic level and what happens with the non-additive genetic variation, why otherwise study phenotypic plasticity, GxE and maternal effects. But my gut feeling is that we come from different fields, and that that might influence our perspectives. -- Kim van der Linde ^{at venus} 14:45, 24 May 2006 (UTC)

I think we need to think quite hard about this. Founders are selected for by happening to be in a particular place at a particular time. In what objective sense is this different from being selected for by happening to be stronger or more fertile? Obviously being stronger is more likely to have a heritable component than being in a particular place. But strength is also about epigenetic effects, maternal nutrition, environmental effects, training (acquired characteistics) - and who knows, maybe being in the right place might have heritable components too (a fondness for solitude or affection for islands?). Now non-heritable mechanisms - well I don't know much about lots of things but I do know a bit about developmental programming, and for instance the early neonatal exposure of animals to stress for instance can programme the adult stress axis - and this early environment is affected by and affects maternal behaviour - so there is a non-genetic inheritance of maternal behaviour that affects adult phenotype in ways that, it has been argued at least, are adaptive. (protective mother vs neglectful mother, affects life strategies in ways that can both be adaptive given different environments and are non-genetically heritable). Now these are rather major influences (The Barker hypothesis etc etc). I'm not for a minute suggesting that any of these should be discussed in detail, or even at all. What I am suggesting though, is that it should be pointed out clearly a) that most selection is not for heritable features b) that for most traits at most only a component is heritable c) that accident and circumstance - chance and contingency - play a dominant part in the fates of most individuals and yet, given enough time, natural selection will amplify the few genetically heritable components, and this simple, blind and crude mechanism, acting out its small role in a sea of accident, fashions evolution. The idea is made great and bold by its smallness and simplicity.Gleng 15:40, 24 May 2006 (UTC)

Partly in response to Gleng on his point higher up. It is important to understand whichever definiton of natural selection is preferred the radical idea which results in adaptive evolution is exactly the same. Nothing is diminished either way. By using the wider definiton some people may always fail to understand selection's blindness. By using the phenotypic defintion others will always fail to understand the link between selection of phenotypes and preservation of charactertics. But these are such fundamental misunderstandings there a limit to what we can do about them.

Good point. We should try to avoid inviting misunderstanding by overemphasising heritability of traits when discussing selection, but we must equally stress that it is selection of those elements that are heritable that are particularly important for evolution. Gleng 20:35, 24 May 2006 (UTC)

The Russ Lande article above (apparently cited 1277 times) qualified his defintion as 'phenotypic selection' and 'phenotypic natural selection'. If we are preferring this definition I think we should do the same. (Even in the wider definition it could be argued natural selection acts on phenotypes - that is different from saying it is the selection of phenotypes and no more.) — Axel147 15:56, 24 May 2006 (UTC)

For what it is worth, my sense is this: natural selection applies to all sorts of phenomena (including the development of neural pathways in the developing brain, and cultural (meaning symbolicaly coded and learned) beliefs and practices) which is why it makes the theory very exciting to many non-evolutionary scientists. However, it certainly helps explain speciation, which is why it was a radical and provocative idea for natural scientists. When applied to the study of neural pathways or culture, natural selection does not require that the material it acts on be inherited. However, when used to explain speciation, the material it acts on does have to be inherited. What the actual mechanics of inheritance are is irrelevant - Darwin knew this (that the material had to be inherited, and it doesn't matter what the rules goverhing inheritence are). Many people, especially in the US, are still shocked by this idea because we have a cultural belief, almost dogma, that what is inherited is immutable. I mean this in the colloquial sense. I am not talking about the mutation of genes, I am talking about a deeply held cultural belief that is more pervasieve (e.g. he is such a good violinist, its his mother's genes - scientifically a meaningless statement, yet an example of the kind of statement most of our readers often make). For the modern synthesis, it is not enough that genes can mutate. As most creationists will rush to observe, mutations are almost always harmful. But this is because they are focusing on the level of the individual organism. I think one of Darwin's points (central to understanding natural selection) is that when you look at things on a much larger scale (a population) mutations produce variation and natural selection acts on this variation in a way that, while harmful for many individuals, is very positive for the population. I have introduced two new terms, variation and scale. I think both are necessary to make the link between inheritence and natural selection clear. Slrubenstein | Talk 10:55, 25 May 2006 (UTC)

Top image

I uploaded a slightly cleaner version of the image (anti-aliased, looks a bit nicer). Let me know if font sizes, line thicknesses, or the text need changing. It's PD, so use at will! - Samsara (talk • contribs) 18:54, 24 May 2006 (UTC)

It is better, except that the color difference between two most resistant versions is pretty much invisible. -- Kim van der Linde ^{at venus} 19:02, 24 May 2006 (UTC)

I tweaked the colours. Take another look! :) Samsara (talk • contribs) 12:08, 26 May 2006 (UTC)

On my computer, it is somewhat better, but I still have a problemto see thatbthe resistant ones are actualy two different colors. Sorry :-( -- Kim van der Linde ^{at venus} 16:06, 26 May 2006 (UTC)

Have now done the same for the second image. I couldn't get it to look quite like the original - let me hear your comments! - Samsara (talk • contribs) 12:54, 26 May 2006 (UTC)

I like it! -- Kim van der Linde ^{at venus} 16:06, 26 May 2006 (UTC)

Diagram of different definitions of NS

File:Natural Selection Usage.jpg

I've made a picture! probably easier than the spaghetti of this thread. Above is what I was tring to say — Axel147 19:36, 25 May 2006 (UTC)

It is wider than my screen, so not easy to see. -- Kim van der Linde ^{at venus} 20:22, 25 May 2006 (UTC)

Out of curiosity, where would you place R.A. Fisher (The Genetical Theory of Natural Selection) and Sewall Wright (adaptive topologies)? Ted 16:43, 28 May 2006 (UTC)

Outward form of an individual

Do we have to worry that nontechnical readers of this article might read "outward form of an individual" to exclude vascular systems, organs, behavior, and the such? Ted 22:39, 26 May 2006 (UTC)

As a "nontechnical reader" of the article, my interpretation of that phrase is physical appearance and possibly behavior - internal organs and such are presumably excluded when you say outward. Moulder 02:32, 27 May 2006 (UTC)

I agree, it might not be the best way to say it, as it would include everything. Maybe TedE has a good proposal, I will also think about how to reword it. -- Kim van der Linde ^{at venus} 02:37, 27 May 2006 (UTC)

I changed it, hopefully, it is clearer in this way. -- Kim van der Linde ^{at venus} 02:41, 27 May 2006 (UTC)

Not to be pedantic but...

The article uses the heading "Genetical theory of natural selection", which sounds odd to me. The -al difference (e.g. historic and historical) generally comes down to personal preference, but is there a difference (perceived or real) between genetic and genetical? I'm curious to know. Moulder 02:30, 27 May 2006 (UTC)

I used it as Futuyama Used it, in his standard work for biology students (Evolution). I have no preference. Is one or the other more linked to British or American english?-- Kim van der Linde ^{at venus} 02:36, 27 May 2006 (UTC)

It's possible Americans prefer genetic and Britons prefer genetical. My preference comes from familiarity with epigenetic theory, but English has no real rules at times. I thought there might be a distinction in academic circles, otherwise I wouldn't bother bringing it up. :) Moulder 02:58, 27 May 2006 (UTC)

I understand. As I said, I have no preferences. If there are no good reasons, I think we might want to stick with Futuyama, who is at least a recognized scholar in the field. -- Kim van der Linde ^{at venus} 03:01, 27 May 2006 (UTC)

See: The Genetical Theory of Natural Selection (1930) by R.A. Fisher, one of the cornerstones to the area by one of the Titans. Ted 04:27, 27 May 2006 (UTC)

R.A. Fisher's The Genetical Theory of Natural Selection is the foundation book of the modern synthesis, and where Futuyama is paying homage by using the phrase. Pete.Hurd 04:38, 27 May 2006 (UTC) (Whups! Ted's edit must have gone in before I hit the edit button! It's like slashdot on this page) Pete.Hurd 04:45, 27 May 2006 (UTC)

I really doubt that the genetical theory of natural selection was first proposed in 1930 by Fisher. I'm away from my collected works of Fisher, but I suspect I could find an earlier paper. I also wouldn't be suprised if Sewall Wright introduced it earlier. Fisher's 1930 book was the first synthesis of many aspects of selection, including such things at Fisher's fundamental theorem of natural selection. Maybe Joan's book can shed some light. I'll check when I get back to my office. Ted 05:33, 27 May 2006 (UTC)

Based on what's at Modern evolutionary synthesis a reasonable candidate for first would be The Correlation Between Relatives on the Supposition of Mendelian Inheritance... sort of... ish... Cheers, Pete.Hurd 05:59, 27 May 2006 (UTC)

In the evolution by natural selection part the word 'genotype' is being used. Shouldn't this be just 'gene' as we are talking several generations? — Axel147 10:05, 27 May 2006 (UTC)

Here's another one, maybe pedantic: should 'A prerequisite for natural selection to result in adaptive evolution is the presence of heritable genetic variation' be qualified? The heritable genetic variation needs to lead to fitness differences. If all variations are fitness neutral no adaptive evolution can happen. (Note when 'heritable variation' is intended as 'hertiable varition in fitness differences' the above qualification isn't necessary, but might help clarity. When talking about heritable variation in genes or traits it is.) — Axel147 11:08, 27 May 2006 (UTC)

As Bruno Latour and Steve Woolgar have explained in their ethnography of science, scientific claims often change over time in a process that eventually leads to their either being dismissed or accepted as fact. This suggests that it would ehlp to look at "genetical" in a historical context. At the dawn of the modern synthesis scientists were working out the implications of genetics for Darwinian theory. Thee was a time when people were not sure what the result would be. It is no surprise that at this time people would use "genetic" (or, if they are brits, who seem always to love an extra sylable, genetical) as an adjective to make it clear to everyone that they wer enot being strictly Darwinian. I think that moment in the history of science has passed. The validity of genetics is well-established, as is the fact that it does not contradict Darwinian models. Attempts to synthasize the two that were preliminary and provisional seventy years ago are now well-established. I do not think that the adjective is needed anymore. All scientists today know that to study evolution you need to know genetics; every article on evolution discusses the impact and value of oour understanding of genetics. In short, it now all goes without saying. My point: genetical natural selection is not a specific theory of natural selection, it was a specific theory at a specific time in the development of the science. I think the adjective is useful only in the historical context. Slrubenstein | Talk 10:59, 27 May 2006 (UTC)

I agree with Slrubenstein, the term while historic, has been replaced by genetic - and seems out of place in comtemporary english (US, AuE, Brit ect).--Peta 11:11, 29 May 2006 (UTC)

Jargon usage

Just a note, to watch out for usage of some words in a way that is peculiar to the field. The frequency of an allele is something WE understand as the frequency in a population - but it is potentially ambiguous or misleading to lay readers. Prevalence might be a better word here, or incidence. As the article (rightly) gets into more technical detail, it is particularly important to watch out to be both rigorous scientifically, but also rigorous in the use of language as it will be understood by a lay reader. (I think I count myself as lay here).:)Gleng 21:03, 27 May 2006 (UTC)

Good point. But many lay people will not really get what we mean by prevalence or incidence. My suggestion is: whenever we use a term of art (even - indeed, especially, when the word is quite common in other contexts) we should have a very brief paranthetical gloss. It might seem pedantic to some, but it will really help others who are not conversant in the language of science. Television is full of shows where one character tells another "Whoa! I am not a rocket scientist" or "In plain English please." I think we need to anticipate such responses AND I do not think doing so requires us to dumb down anything. It just means that whenever we use jargon (including using words familiar to everyone, but in unfamiliar contexts or ways) we just have a paranthetical explaining what we mean in non-jargon. This in a way is the point I was making about "adaptation" - everyone knows this word, but most people don't understand how evolutionary scientists use it. That's why I think ever time an evolution-related article uses the word "adapt" or "adaptation" we need a paranthetical that says (for scientists, this word does not refer to the intentional act of an individual, but to the effect of unintional processes on individuals). I have not actually added this paranthetical because I do not want to write against a consensus. Kimvlinde, do you object to this? Gleng? Axel? Graft? If no one objects, I will put it in. Slrubenstein | Talk 12:35, 28 May 2006 (UTC)

I think this is a good idea - maybe a short glossary in a text box, so as not to break the flow of reading? and especially for words whose technical use might conflict with common use? Gleng 13:13, 28 May 2006 (UTC)

Let's see what others think. I am opposed to a glossary - no other Wikipedia article has it and I think it is bad form in an article (glossaries are I think appropriate for books). I think a short paranthetical the first (and only the first) time a word is used will not be too much, will not render the text overwrought. Slrubenstein | Talk 13:16, 28 May 2006 (UTC)

Fine by me, try it.Gleng 13:19, 28 May 2006 (UTC)

I think that a good article is self explanatory, and we have dealt with several terms by just explaing them. I do not think we should do that in the lead, which the previous discussion kind of circled around. I had the impression that Gleng comment was primarily based on the genetic sweep sections and such that use more jargon. I actually think we have to copy and past some of that information to seperate articles, after which we can condense the stuff to a more resonable proportion of the full text. -- Kim van der Linde ^{at venus} 17:12, 28 May 2006 (UTC)

Anything that is potentially ambiguous, should have a link to an article of its own or a Wiktionary entry. I think jargon should have a brief explanation, but once allele frequency is linked, the reader has access to a definition of the term. Guettarda 17:58, 28 May 2006 (UTC)

I would be completely with you, but I try to keep in mind that the topic of this page is also atrackting a lot of people who really start from the basics, so I think it is warranted to explian slightly ore than in many other articles. Just my 0.02 Euro cents -- Kim van der Linde ^{at venus} 18:08, 28 May 2006 (UTC)

I agree with Kim. My position is that technical terms should have - if not at the very first instance (e.g. in the introduction section) then in the first instance in the body, very brief explanations. I believe this because I think many people reading this article will not follow the link. Certainly, if someone thinks they know what the word adaptation means - and they actually do, in a colloquial context, they probably will not follow the link. This is unfortunate because if they followd the link they'd discover that the word means something slightly different in this context. Nevertheless, I think many won't follow the link. SO some kind of minimal explanation of jargon is necessary. Kim, if you and I differ only in that you feel that such explanations shouldn't be in the lead, I am fine with that - would you oppose the kinds of parantheticals I suggest at the first instance in the body? Do you want to propose some, or should I and then let others revise them? Slrubenstein | Talk 13:06, 29 May 2006 (UTC)

I am fine with parentheses, explanatory sentences, or whatever is needed to make it clear. I would prefer for the lead to have it self-explanatory, without parentheses, but if needed, fine. What I am more concerned about is the general line of the article, but it slowly becomes clear to me that I should back of from this article and spend my time with other articles. -- Kim van der Linde ^{at venus} 16:00, 29 May 2006 (UTC)

Axel's rewrite of the definiton section

For reference, the edit referred to in the following is [2]. - Samsara (talk • contribs) 18:27, 30 May 2006 (UTC)

I am not happy with Axel's changes of the definition section, as I think that as it is curently worded, it sounds like the article is incomplete because we use the non-complete definition. Besides that, I think it is incorrect, heridity perse is never part of the definition (if so, that would result in the inclusion of processes like mutation, recombination etc), but the result related to heridity is sometimes included. If it is included, it will affect all heritable traits, not some. And no, it does not always lead to adaptive evolution, it most of the time results in consolidation (stabalizing selection).

I am not going to change it because this seems a big deal to him, and the rest of the article is in pretty good shape. But I would like to hear other opinion about it. -- Kim van der Linde ^{at venus} 17:12, 28 May 2006 (UTC)

I do agree with you, but that's about all I can contribute to the conversation - my interest in the page is mainly what I learn from it. Moulder 03:59, 29 May 2006 (UTC)

It seems silly to say that natural selection is only survival to reproduction in the defintions section, then in the very next section include a diagram that shows much more to selection than simple viability selection. This discussion will go nowhere until you see the problems inherent in the definitions. Go up to the section on Talk:Natural_selection#Diagram_of_different_definitions_of_NS and try to answer my question about Fisher and Wright. If you can figure out what they are talking about (and surely they are the two that originally defined the field), then I feel the rest will go much easier. Ted 04:48, 29 May 2006 (UTC)

It seems to me that Fisher uses selection in the mechanistic sense. Consider two individuals in a generation, one who has inherited a beneficial allele and another who has not; does it make sense to say that one has been selected by NS and not the other? Or consider two individuals with the same trait, in one of whom the trait is inherited and the other the trait is acquired, both of whom reproduce; does it make sense to say that one is selected by NS to reproduce but not the other? In both cases, both individuals have been selected to reproduce, and in both the process of selection is a natural one.

It's hard to resist this verbal linkage and I think this is why we have 2 definitions. But many things are selected in nature and that's not automatically 'natural selection'. Darwin simply did not define NS in this way. He wished he'd used the term 'natural preservation' but it was too late. Nothing in the modern synthesis forces us redefine natural selection so the Darwinian usage is still with us. I doubt Fisher used it differently but I'm interested to check it out. — Axel147 01:33, 30 May 2006 (UTC)

Throughout Fisher’s work is the sense that NS is a mechanism, multifacetted and stochastic, involving heritable elements as just one aspect, though the important aspect for adaptation. If you include the outcome as part of the mechanism, you’re liable to get stuck with a logical absurdity if you want to use NS as referring to individuals as the unit of selection. So I’m not sure what Ted’s point is exactly. Axel’s concern I think I understand better, if there is a disagreement I think it’s mainly in differing perceptions of where misconceptions are more likely to arise by the reader. Anyway, below would be my preferred version, more to set out my position rather than to suggest it as a replacement, and clearly reflecting my concern to emphasise the lack of direction of NS and its ultimate simplicity and inevitability.

Definitions of natural selection

In any generation, only some individuals will leave progeny. We can think of this as being a "natural” process of selection of individuals to reproduce. Individuals with certain traits are more likely to be 'selected' than individuals with other traits. When such traits have a heritable component, they will become more common in the next generation.

No mechanism of selection of individuals in a population can ‘know’ which traits are heritable; in this sense, the mechanisms of selection are ‘blind’. However, the term "natural selection" is often used to encompass the consequence of blind selection as well as the mechanisms; i.e. to describe the complete process that leads to the preservation of useful characteristics -. the 'blind' selection of individuals followed by propagation of some of their characteristics through inheritance.^[1].

Nevertheless, for scientists today it is often important to distinguish clearly between the mechanisms and the effects of the mechanisms. Accordingly, they may define “natural selection” specifically as ‘those mechanisms that contribute to the selection of individuals to reproduce’, without regard to whether the basis of the selection is heritable or not. This is sometimes referred to as 'phenotypic natural selection' to emphasis its precision^[2]

This article uses this precise, phenotypic definition of natural selection to describe and explore how it operates.

Gleng 16:23, 29 May 2006 (UTC)

Gareth, I have taken your version, and have changed it somewhat, please let me know what you think of it. In general, I think this is a good alternative, and this would be my version:

Of the surplus of offspring in each generation, only some individuals will successfully produce offspring themselves, and of those that reproduce, some are more successful than others. We can think of this as the "natural” process of selection of individuals to reproduce. Individuals with beneficial traits are more likely to be 'selected' than individuals with other traits. When those traits have a heritable component, they will become more common in the next generation.

The mechanism of selection of individuals in a population does not ‘know’ which traits are heritable; in this sense, the mechanisms of selection are ‘blind’. However, the term "natural selection" is regularly used to encompass the consequence of blind selection as well as the mechanisms; i.e. to describe the complete process that leads to the enrichment of the beneficial characteristics in the next generation.^[3].

At the same time, it is often important for scientists today to distinguish clearly between the mechanisms and the effects of the mechanisms. Accordingly, they define "natural selection" specifically as ‘those mechanisms that contribute to the selection of individuals that reproduce’, without regard to whether the basis of the selection is heritable or not. This is sometimes referred to as 'phenotypic natural selection' to emphasis its precision^[4]

This article will first discuss the mechanisms itself, followed by the changes it can have on the underlying genetics, and will finally venture into the realm of evolution by means of natural selection.-- Kim van der Linde ^{at venus} 02:07, 31 May 2006 (UTC)

Would be a good compromise. What about natural selection at other levels? (Think, since Aristotle, scientists have always distinguished cause from effect, not just 'scientists today'.) — Axel147 23:24, 29 May 2006 (UTC)

Kim, what do you mean by "heridity [sic] perse [sic] is never part of the definition?" I don't think it is simply coincidental that the early people who developed the field of population genetics are also those who developed the field of quantitative genetics. Not just Fisher and Wright, but also Lush, Li, Robinson, Robertson, Cockerham, Kempthorne, Falconer, etc. Ted 01:08, 30 May 2006 (UTC) Nevermind. I see that KimvdLinde has stated she will no longer respond to discussion with me. It seems that I tend to reference dead people. Ted 04:52, 30 May 2006 (UTC)

Who are we writing for?

Kim's characterisation above of my concerns is correct, I was worried about jargon "creep" into the later sections. RA Fisher I know better as a statistician, and there's a passage of his that I often use, where he argues against argument from authority: Of statistical tests, he says "the questions involved can be dissociated from all that is strictly technical in the statistician's craft, and, when so detached, are questions only of the right use of human reasoning powers, with which all intelligent people, who hope to be intelligible, are equally concerned, and on which the statistician as such speaks with no special authority" To me this expresses the ideal of what we should be trying to do here, to explain natural selection, and the logic and power of the arguments, in ways that all intelligent people can follow without specialised knowledge. I'm not suggesting "dumbing down" or that sophistications should not be introduced, but only that we should be careful to write for the intelligent reader who comes to the article with no specialised knowledge. (For this reader especially we must be careful e.g. not to use 'allele' and 'gene' as though they were interchangeable, or talk of the phenotype of a gene when we've defined it as the property of an individual)

In any generation, only some individuals will leave progeny. We can think of this as being a process of "natural selection" of individuals to reproduce. Individuals with certain traits are more likely to be 'selected' in this sense than individuals with other traits. When such traits have a heritable component, they will become more common in the next generation.

It seems to me that this is the core, the beginning of a logical progression that anyone can follow.Gleng 10:34, 29 May 2006 (UTC)

I was interested in the Gleng/Graft discussion on whether founding a new population is in fact a result of selection? After thinking about this and re-reading Sober's chapter on chance I think the answer is we have both cases (but again it could depend on definitions):

Natural Selection - e.g. a trait exists which increases liklihood of founding new population. (Here selection could operate at the group level.)
Founder Effect - e.g. an intrinsically random event such as a one-off meteor strike destroys part of a population and splits it into two.

Sober seems to support this idea of both possibilities when he considers two 'phenotypically identical' twins, one struck by lightning. He says, 'One must be willing to treat organisms that differ in their [actual] reproductive success as identically fit to capture biologically significant generalisations.' Part of the reasoning is that the world is non-deterministic current state does not guarantee future state.

He later feels the need to qualify 'differential proliferation and extinction' of groups by requiring this not to have occured by chance i.e. to be 'nonrandom differential proliferation and extinction'. (Note the revised definiton is still not group selection as Sober goes on to emphasise but this is a different point.)

So I think I agree with Sober's implication that natural selection requires some property to select (and that just being in a different place isn't enough). In other words natural selection is differential reproduction correlated with fitness differences, not just any old differential reproduction.

I would suggest differential reproduction or Futuyma's 'statistical differences in reproductive success' could happen by chance if a population is hit by a meteor. Not just blind with respect to inheritance but totally blind. But is this natural selection? — Axel147 22:33, 29 May 2006 (UTC)

There is a problem. How can you ever tell whether survival is the result of chance or not? I don't think you can objectively, and I suspect that any attempt to do so will end up in the circularity of defining natural selection by its outcome. So I think the clean answer is that natural selection is all selection that doesn't involve a designer, and that heritable traits influence the probability of selection, and why I think that in the end, this is why heritability cannot coherently be part of the definition. Fisher analysed the impact of selection on populations: I don't think it is possible to think of the effects of "natural selection" on a population as separable from the effects of "other sorts of selection" on a population. For any individual, how could you tell why he has been selected? It's all natural selection, it's just that some involves heritability and some does not.Gleng 11:51, 30 May 2006 (UTC)

I agree this is a problem. The point I am making above is all about chance vs. selection for a property i.e. selection with a cause/reason (nothing to do with inheritance). But there is there no reason to define something just so we can objectively measure it. (This was meant as a philosophical point as aside from my serious point about the definition) — Axel147 12:28, 30 May 2006 (UTC)

As a separate point to Gleng, when Dawkins says 'natural selection, the mechanism that Darwin and Wallace suggested, amounts to the nonrandom survival of randomly varying hereditary characteristics' you may not agree with him. But I don't think it's helpful to say the use of heredity is 'incoherent'. Dawkin's 'Blind Watchmaker' was specifically emphasise selection's blindness. It's just he doesn't equate 'selection' with the term 'Natural Selection'. Both points of view are coherent otherwise we could easily dismiss one. We are are just using terms differently and unless we see this it will be difficult to make progress. — Axel147 13:28, 30 May 2006 (UTC)

Yes, I do see your point, and didn't at all mean to be judgemental (good grief, who am I...), I meant coherent in the sense of "sticking together" not in the sense of being unintelligible - sorry about that. You'd like to dissociate the "signal" from the "noise", but we can't tell what is signal and what is noise except statistically on populations. I agree that metaphysically you can distinguish them, but I kind of go with Feynmann, it's when you can measure things that really makes science become powerful, Fisher made natural selection measurable in its effects, and for it to make sense in terms of what he measured, natural selection is the mechanism not the effect. I agree that when people talk about Natural selection they sometimes use it for the mechanism, sometimes for the effect, sometimes for both, and I think most people actually glide amongst these depending on the context. It doesn't often matter after all, and it's a kind of shorthand that encompasses a lengthy explanation that can be made if you have to. I think we must acknowledge that people use this term in various ways. But within the article, if we're not clear about exactly how we're using it, then what we write may be illogical or simply wrong on a different, but reasonable readingGleng 15:37, 30 May 2006 (UTC)

Another try for a definition (deleted due to lack of interest)

This section was deleted by me (the author) due to lack of interest in the process. Ted 01:27, 4 June 2006 (UTC)

Posted at TedE's talk page

I posted this at TedE's talkpage, but I think the rest might want to know as well:

Ted, thanks for the invitation for the renewed definition discussion at NatSel. I think however that it is wiser that I let it in your hands and refrain from participating. There is still a lot of work that needs to be done at other important article that I for the moment prefer to concentrate on those instead of spending my energy on a renewed definition discussion. Best -- Kim van der Linde ^{at venus} 19:08, 30 May 2006 (UTC)

Good luck with the renewed definition discussion! -- Kim van der Linde ^{at venus} 19:50, 30 May 2006 (UTC)

who are we writing for exactly?

I'm just passing by this article, and certainly don't feel any ownership, where it goes it goes. I thought this was something important for WP though because of another space - the search space. This article will get a lot of hits from lay people, high school students, some attracted by creationist controversies, some by popular science articles etc etc. It's a quite different audience to those who will search for say population genetics. So it seems to me that this page is inevitably a portal, and we mustn't scare anyone off, or try to dazzle them with either authority or sophistication too fast, but be clear, interesting, and get the essence of the important ideas across in an accurate way and make the arguments internally consistent. I don't think that the intention was ever not to characterise different usages, or to "prioritise" one except for the important purposes of internal consistency for logic and clarity. Ted is raising interesting issues here, - you have to think carefully through how statements about the gene/individual/group as the unit of selection fare for instance. I am far from sure whether it is possible to find a definition that can be applied consistently across levels, and would be very interested in following a discussion. My reservation is not about the value of this - only about whether this article is the right place. Like I suspect everyone here feels, there are no fundamental scientific differences here, just different perspectives from different backgrounds. The rght answer depends on who's asking the question; it's the same answer I hope, but couched differently. So here, who are we writing for? Or rather you, because like Kim I should really move alongGleng 20:12, 30 May 2006 (UTC)

One of the joys of contributing to this article is not just that natural selection is an immensely powerful idea but as Gleng says that this page will almost certainly serve as a portal for such a broad and important area of science. I really believe we are close to a solution. Though we occasionally discuss ferociously I also agree with Gleng there are no fundamental scientific differences, no fundamental differences in understanding of evolution. I do think there a two different major definitions which cannot and should not be merged (as in my diagram) but I also understand those who say we should not get bogged down in terminological questions which detract from the real science. My preference is to identify differences without dwelling on them rather than papering over them. I think Slrubenstein is right to say all we can do is acknowledge and explain the major viewpoints. And I think Gleng's summary of the defintion question question is a very good one and we should use a version of it. Maybe I argued it from the opposite side of the fence and my language was not neutral enough. I welcome Ted's efforts for achieving clarity and understanding where people are coming from is likely to be the key to this, but think a minor tweak should do the job.

I also welcome Kim's efforts not in only in rewriting this article and making it more readable, but also for considering the definition issue. I think Kim and I were the first people in the thread to acknowledge 2 definitions. The slight disagreement as to which is the more important and which how the difference should be expressed is really quite small.

For the record I have an MA in chemistry but I am not a practising scientist. My hope was and is that we can provide a well rounded article, with rigour and clarity. One accessible to the layman and in this way one that reflects the historical importance, current biology and one that is 'creationist-proof'. I really feel we are very close. — Axel147 22:33, 30 May 2006 (UTC)

I'm happy with Kim's rewrite and glad to see that we might be close to a stable solutionGleng 08:37, 31 May 2006 (UTC)

Not quite happy. Just a tweak to get there...

I looked in my local library last night and 7 out of 7 dictionaries and encyclopedias of biology did not use the phenotypic def. so against my better judgement I will only I agree to using it as a lead if we are absolutely neutral about both definitions in the definition section. It's proabably useful to say terms such as 'principle of natural selection', 'theory of natural selection' tend to be historic and now most people prefer to describe NatSel as a process/mechansim. In terms of neutrality. For the phenotypic defintion it's important we have no pejorative suggestions that it is

Only part of the whole story
Close to being reducible to tautology

For the wider definition we need no suggestion it's:

Not mechanistic
Not current (even though I think it was preferred historically)
Equal to the outcome 'Evol by NatSel'
Loose/imprecise
Not scientific mainstream

Also no general suggestion that separating mechanism from outcome is a new thing. I think also we should explicity use the word inheritance/heredity/heritability rather than ducking it. Please see Endler Talk:Natural_selection/Archive_003#Endler_-_Thankyou!.

I propose, I mean request Gleng does a tweak bearing some of this in mind to keep us all happy. — Axel147 08:55, 31 May 2006 (UTC)

Well, thanks for the confidence, though it's probably misplaced. Axel's points are fine to me. I've just done a Google search for definitions of natural selection: most don’t really define it at all, but say something like “ a natural process that results in the survival and reproductive success of individuals or groups best adjusted to their environment and that leads to the perpetuation of genetic qualities best suited to that particular environment”. This statement is consistent with any definition we’ve talked about (if it’s taken as a statement about natural selection rather than a definition of it). If we were in conflict with these, then I’d be worried, but I don’t think this is the case. Anyway I’ve tweaked Kim’s version, thought about Axel’s points, looked at the article again to see where this section lies in relation to the rest, and come up with this suggestion.

Of the offspring in each generation, only some individuals will produce offspring themselves, and of those that reproduce, some will leave more offspring than others. We can think of this as the "natural” process of selection of individuals to reproduce. Individuals with beneficial traits are more likely to be 'selected' than individuals with other traits. When those traits have a heritable component, they will become more common in the next generation. The mechanism of selection of individuals in a population does not ‘know’ which traits are heritable; in this sense, the mechanisms of selection are ‘blind’.

However, the term "natural selection" is often used to encompass the consequence of blind selection as well as the mechanisms; i.e. to describe the complete process that leads to the enrichment of the beneficial characteristics in the next generation.[3].

Nevertheless, it is sometimes helpful to distinguish clearly between the mechanisms of selection and the effects of selection. When this distinction is important, scientists define "natural selection" specifically as ‘those mechanisms that contribute to the selection of individuals that reproduce’, without regard to whether the basis of the selection is heritable or not. This is sometimes referred to as 'phenotypic natural selection' [4]

From here on, this article discusses natural selection in this sense of being the mechanisms of selection of individuals to reproduce. Of particular importance is selection according to traits by which individuals differ from each other. It discusses the effects of this selection on the genetic characteristics of a population when some components of beneficial traits are heritable. Finally, the article ventures into the consequences of these effects for evolution.

Gleng 10:57, 31 May 2006 (UTC)

Fine with me. -- Kim van der Linde ^{at venus} 12:42, 31 May 2006 (UTC)

Fine with me! — Axel147 13:40, 31 May 2006 (UTC)

How does balancing selection fit into the first paragraph? Ted 18:06, 31 May 2006 (UTC)

I don't see a problem. Balancing arises by selection of individuals on the basis of their fitness, just in this case individuals with different genotypes are selectedGleng 19:07, 31 May 2006 (UTC)

True, but "they will become more common in the next generation" isn't true when they are at equilibrium. Ted 19:47, 31 May 2006 (UTC)

This statement has too much of the feel of design. It is as if there is something physical (or, metaphysical) that is evaluating individuals and deciding to keep or reject based on their phenotype. I don't think this is what you want to say. Ted 18:10, 31 May 2006 (UTC)

Certainly something we all want to avoid; obviously I didn't read this into the above myself - any suggestions?Gleng 19:02, 31 May 2006 (UTC)

Maybe we should add a 'tends to' and 'in the absence of other evolutionary forces' to be clearer — Axel147 21:54, 31 May 2006 (UTC)

Good catch Ted, potentially good solution Axel or replace 'in the absence of...' with '(but see balancing selection for exceptions). "When those traits have a heritable component, they will tend to become more common in the next generation (though not always, for one exapmle, see balancing selection for exceptions)."??

Anyway, I'm tied up for a bit now with exam boards so it's up to you guys. Axel, if you're willing and able to make the improvements to the definition section I think there's consensus that we have an improved version; perfection is beyond any or all of us (it will evolve).Gleng 10:49, 1 June 2006 (UTC)

Passive process

What do you mean by "passive process?" I presume it is a pre-emptive strike against Intelligent Design, but I'm not sure it really fits. Is selection a passive process to the organism? The individuals are certainly part of the selection process, particularly when you study behavior. Selection is a ~~random~~ stochastic process, based on the inherent properties of the individuals. That doesn't seem passive to me. Ted 18:25, 31 May 2006 (UTC)

I agree, passive is redundant and if it needs to be explained to be justified then it doesn't belongGleng 19:03, 31 May 2006 (UTC)

But you don't mean random here do you. It's hard isn't it, to find the right wordsGleng 19:29, 31 May 2006 (UTC)

Yes, I do mean random process. It doesn't mean undirected, it simply means you can't predict the actual results (there is randomness). If I were to close my eyes while driving down a road, I will hit some random object (another car, lightpole, bridge, tree, etc.). Not all possible targets have equal chance, but I can't predict exactly which one I will hit. That is random. Unfortunately, most people tend to think that random means uniform random. Ted 19:42, 31 May 2006 (UTC)

But there lies the problem Look in a dictionary for random, and you'll find something like "Of or relating to an event in which all outcomes are equally likely" and look up "random process" technically and that won't fit either. I know what you meant, but choosing the right words depends on a sense of who you're writing forGleng 20:32, 31 May 2006 (UTC)

I agree entirely. My dictionary (American College Dictionary) lists both random and random sampling. Only random sampling mentions equally likely. I'll try to be more careful. I've replaced random with stochastic. Ted 20:40, 31 May 2006 (UTC)

Inherent in the 'natural selection' metaphor, is the idea nature is doing the selecting. The whole point is that selection is not random in the sense of it being unbiased: it is biased towards fitter phenotypes (but of course it is blind as to whether the features are heritable). The process of selection is obviously probabilistic, not deterministic so maybe we should add a 'tends to' and 'in the absence of other evolutionary forces' to be clearer — Axel147 21:11, 31 May 2006 (UTC)

Kim put in the word "passive" in response to a concern I raised. I am not committed to the word "passive" but I do think my concern remains valid and should be addressed in the article. Most people - even some biologists, but I mean most if not all lay-people - believe that the verb "adapt" revers to an intentional act. Moreover, I believe most believe that "adapting" is akin to "learning." Thus, many people assume that "adaptations" are usually learned behaviors, the result of the intentional act of adapting. Now, it seems to me that even in Darwin, certainly in the modern synthesis, adaptations are (1) non-intentional and (2) inherited rather than learned. I believe that the article communicates this, but I believe it communicates this in a way that is evident to anyone with a decent science education - but in a way that many if not most lay-people (and most people have a pretty bad science education, at least in the English-speaking world) will not really appreciate. For this reason, I felt that these differences (between how evolutionary scientists use the words "adapt" and "adaptation" and how lay-people colloquially use the words) need to be highlighted in this article. I suspect there are a number of ways of doing this. My own way would be to have a paranthetical saying "(in evolutionary science, adaptations are inherited rather than learned, and unintentional)" or something like that. What do you guys thing? Please come up with something very explicit, because I think that this really needs to be highlighted the first time "adapt" or some variant of the word is used, at least in the body of the article (if not in the lead) Slrubenstein | Talk 10:02, 1 June 2006 (UTC)

I think your concerns are absolutely right. I'm tied up now for the next couple of days at least. I doubt if there is anything but support for your intentions here. I think this is why this article has been so hard - we're trying to write for a lay audience in a way that is going to be rigorous when read by an expert (or rather by experts from many different perspectives). Go ahead and tweak. This article is everybody's.Gleng 10:38, 1 June 2006 (UTC)

What selection is natural selection?

What types of selection do you consider to be part of Natural Selection?

viability selection
fertility selection
fecundity selection
gametic selection
mate selection
truncation selection
gametic selection
hybrid dysgenesis
sexual selection
kin selection
group selection
clonal selection
balancing selection
stabilizing selection
altruism
reciprocal altruism
density dependent selection

Ted 18:25, 31 May 2006 (UTC)

Feel a bit like I'm the Weakest Link here but I think truncation selection is an artificial algorithm for selection. Don't know if you can call altruism or reciprocal altruism mechanisms, they are certainly features that influence survival of individuals so will have an impact upon natural selection. Pass on a couple but most I'd recognise as submechanisms of natural selection. I know Fisher seemed to write of sexual selection as different from Natural selection, but my reading of him, (perhaps very wrong because I've only quickly looked at some of his writing on selection), is that he saw a "category difference" - "Natural selection" is the name of the set, the above include some members of the set, particularly those members the represent mechanisms that often involve heritable traits. I shouldn't get into this, I'm lousy at pub quizzes too :) Gleng 19:22, 31 May 2006 (UTC)

Sorry, I didn't mean it to come off as a pub quiz, although if you want a pint before thinking about it, go ahead. I tried to come up with a smattering of selections that are found in the area. I chose some classical and some quantitative; others are ecological or social; some have individuals as units of selection and others have hives as units of selection; etc. Do we want to cover all of these? A subset? If so, what subset? Do we want a definition to be inclusive or exclusive? How much simplification? I guess I'm strange wanting to understand what the discussion should cover before writing. It certainly helps with larger projects, such as books. Ted 20:17, 31 May 2006 (UTC)

I was tempted to try the quiz but got stuck. I think they are mainly sub-mechanisms too. They generally identify either a different property being selected which is a subset of fitness, or a different object being selected i.e. a different level of selection. Providing there are phenotypic differences (of any object at any level) that cause differential reproduction we have a form of natural selection. (Ought to qualify by saying while this true it is also possible to have competing selection that cancels iself out and therefore does not result in diffferential reproduction. So maybe I should withdraw that one-liner!!??!!). Brainstorming all types of selection is interesting but seems more useful if we are creating something new. But as natural selection exists already I think maybe we can define that first using other reference points and then see where the other terms fit in?? (And add this in the specialist section for the non layman!) But as a matter of interest do you have the anwsers.... — Axel147 21:45, 31 May 2006 (UTC)

The "quiz" was not meant to have a specific set of right answers. Instead, it is a gauge about how people view selection. Some population geneticists would include all forms of selection as natural selection, preferring to think only of natural vs artificial selection. Others would only include those forms where the individual is the unit of selection (excluding Hamilton's altruism, Williams' sexual selection, Trivers' reverse altruism, Wilson's group selection, etc). That, of course introduces problems, such as with bacteria where the selection is clonal (or "infection-al"). It is, instead, a test to see if you are a clumper or a divider. (PS. My apologies for actually referencing someone who is not quite dead yet. I know it is out of character.) Ted 17:27, 1 June 2006 (UTC)

Well, I saw this article as a portal, essentially for the intelligent layman, with links or entries into I guess all of these in some way rather than covering any in particular. But now you mention it, a sction on natural selection in termite species would be fascinating and aperhaps a great way of introducing some of these subtleties to the lay reader. Want to have a go at it?Gleng 20:42, 31 May 2006 (UTC)

If you want it to be a portal, then I suspect you would want to take a more inclusive view of natural selection, plus trying to spin off most of the material to other articles. Ted 17:27, 1 June 2006 (UTC)

Lead section

Not to put any additional pressure, but "For the planned paper Wikipedia 1.0, one recommendation is that the paper version of articles will be the lead section of the web version. Summary style and news style can help create a concise intro that works as a stand-alone article." (WP:LEAD). Ted 20:24, 31 May 2006 (UTC)

Chrrrpbrcheep. Gleng 20:43, 31 May 2006 (UTC)

Change to defintion section put in

I've added the change to the definition section for which there was more or less agreement. I left out balancing selection. If we'd claimed natural selection resulted in adaptive evolution I agree balancing selection would be an exception. But we didn't say this. We only considered one generation. As I understand it for a given generation at a given context it is still fair to say 'beneficial traits tend to become more common'. What is beneficial may differ from generation to generation as the frequency changes but for I single genration I think it's still valid. — Axel147 22:08, 1 June 2006 (UTC)

Axel, natural selection in general does not result in adaptive evolution, it can do it, but in general it results in balancing selection keeping things nicely as it is, keeping gene-frequencies etc nicely as they are. That is why it is so important to keep evolution and adaptation seperate from Natural selection. -- Kim van der Linde ^{at venus} 23:34, 1 June 2006 (UTC)

True I'm not disagreeing with you. In fact for the wider definition I was emphasising this point. For me it is wrong to say Darwin's 'preservation of favourable characteristics' is synonymous with 'evolution by natural selection' for exactly this reason. When looked at over a single generation or a few generations, preservation of favourable characteristics is compatible with both balancing and stabilising selection. It does not need to result in adaptive evolution. Just to be absolutely clear it is because Darwin is saying it is a principle not a 'must have' outcome. Of course even the outcome 'evolution by natural selection' need not be adaptive either. — Axel147 07:08, 2 June 2006 (UTC)

Do you mean stabilizing selection? Balancing selection seems to be rather rare, unless you look at multiple niches. Isn't stablilizing selection also adaptive? I don't think you have to restrict adaptive evolution to directional selection. Ted 02:29, 2 June 2006 (UTC)

^ For example: Endler JA (1986) Natural Selection in the Wild. Princeton University Press
^ For example: Lande R & Arnold SJ (1983) The measurement of selection on correlated characters. Evolution 37:1210-26; Futuyma DJ (2005) Evolution. Sinauer Associates, Inc., Sunderland, Massachusettes. ISBN 0878931872
^ For example: Endler JA (1986) Natural Selection in the Wild. Princeton University Press
^ For example: Lande R & Arnold SJ (1983) The measurement of selection on correlated characters. Evolution 37:1210-26; Futuyma DJ (2005) Evolution. Sinauer Associates, Inc., Sunderland, Massachusettes. ISBN 0878931872

[1] For example: Endler JA (1986) Natural Selection in the Wild. Princeton University Press

[2] For example: Lande R & Arnold SJ (1983) The measurement of selection on correlated characters. Evolution 37:1210-26; Futuyma DJ (2005) Evolution. Sinauer Associates, Inc., Sunderland, Massachusettes. ISBN 0878931872

[3] For example: Endler JA (1986) Natural Selection in the Wild. Princeton University Press

[4] For example: Lande R & Arnold SJ (1983) The measurement of selection on correlated characters. Evolution 37:1210-26; Futuyma DJ (2005) Evolution. Sinauer Associates, Inc., Sunderland, Massachusettes. ISBN 0878931872

[1]

[2]

[3]

[4]