Talk:Artificial selection

Differentiating

Artificial Selection and Selective Breeding are distinguished both by process and outcome.

Artificial Selection is a process by which humans or other organisms, through a process of elimination or reproductive restriction, select which members of a population of organisms will reproduce. This process differs from Natural Selection in that the individuals selected to survive and reproduce do not necessarily possess traits that would be beneficial or provide any reproductive advantage in the "natural" environment outside the protection of the humans or other "selectors". It is this process that domesticates organisms.

Selective Breeding is a process by which individual organisms with certain traits preferred by the breeder are deliberately chosen to produce offspring with these desired traits. This differs from Artificial Selection in that the organisms chosen to breed are removed from the general population to establish a new breeding population, whereas in Artificial Selection those individuals with undesired traits are simply removed from the original population. It is the process of Selective Breeding that produces distinctive breeds of domestic animals and plants.

In general, Selective breeding produces a population with a particular trait. Artificial selection produces a population lacking an undesireable trait.

There is no evidence given to support this. As the article and Darwin himself defined the concept, it includes both intentional and unintentional selection; selective breeding would therefore be a type of artificial selection, not another side of the human-based selection coin. Richard001 08:03, 11 June 2007 (UTC)

Intro

I rewrote the intro. I did not find the previous intro to be very clear -- perhaps this is because this is a complicated topic, but I did not change the rest of the text so I hope the complexities are still here. I changed it with an eye towards two things: first, not defining AS as a residual category; second, framing it in terms of a more general theoretical context. SR —Preceding unsigned comment added by Slrubenstein (talk • contribs)

Baldwinian

Did I miss something? Can someone tell me how any of this is different from Baldwinian evolution? It seems to me that natural scientists theorized all of this a hundred years ago and I am surprised that the article does not inform readers as to this history. And why call it "artificial selection" when for a hundred years people have called it something else? SR —The preceding unsigned comment was added by Slrubenstein (talk • contribs). Yipes! More from 24's canon:

Artificial selection is a specific type of Baldwinian evolution, which itself is a specific type of Darwinian evolution. According to Darwin, evolution occurs through natural selection, whereby environmental conditions determine the relative success of specific traits. This model seems to present organisms as passive. But James Baldwin pointed out that organisms can alter their environment, and thus alter selective pressures, which can thus affect the evolution of the organism's own species.

Artificial selection is a not a type of Baldwinian selection, nor is every example of Baldwinian selection neccesarily a type of artificial selection. Without going into too much detail here, Baldwinian selection is an evolutionary theory dating back to the end of the 19th century describing how what was originally learned behaviour can become innate behaviour (essentially via the usual route of natural selection). It primarily arises in studies of evolutionary psychology and in particular the evolution of language in humans.

Amongst other bad examples (e.g., harems, and economic conditions), there is this fallacious jump:

However, a more obvious artificial selection takes place when an unmarried human male is imprisoned for a crime - removed from the general human society and mating environment for a period of time - most likely for the aggression or valuables-gathering capabilities that natural selection must encourage.

This would require the inferrence that these very tendencies - aggression or "valuables gathering capabilities" in this case - are demonstrably inheritable (let alone "... that natural selection must encourage" them - consider altruism). The whole nature/nurture argument suddenly becomes an "obvious" example of artificial selection. One might try to imply that, in the United States, where non-white racial designation correlates with imprisonment, that this would have a discernable genetic effect; but that's not what is being asserted here.

Controversially, profound examples of artificial selection are often said to be seen in humans themselves, who employ substantial cultural bias in mate selection, most obviously in the preference of human females for socially powerful mates - a factor which is not directly related to natural ecology or to simple secondary sexual characteristics...

...or even inheritable characteristics; or is this article espousing the view that being "socially powerful" is an inheritable characteristic on a par with having red hair? See sociobiology for this type of theory.

... sexual selection in all mammal species favors aggressive males, and that males of other primate species trade food for sex...

Uhhmmm, bonobos much? Polyandry as a phenomenon in humans and other mammals? Presumption that aggression = greater access to food sources? Other animals such as anglerfish as blatant counterexamples? Etc.?

Were a Marxist or feminist view to predominate, then their shared humanism would be artificial selection.

Come again? Is "amenability to marxism" then a distinctive inheritable characteristic?

Some believe the term artificial selection should be employed only to make a distinction between the human-chosen "artificial" factors and the combination of instinct and ecology that is "natural" without human choice.

Along with almost all biologists, ecologists, creationists, and evolutionary theorists, count me in this camp. Certainly, when very few people use the term in any other way, it makes sense for an encyclopedia entry to use the standard meaning of the term, rather than a personal essay on all things vaguely political and evolutionary. All of this may be interesting speculation in the areas of politics and sociobiology - but it's not a very good definition of artificial selection! Chas zzz brown 04:01 Jan 31, 2003 (UTC)

Dairy Cows are also a good example of artificial selection, we bred these cows to constantly produce milk and they have to be milked every 12 hours. They have become dependant on us and if they are not milked they will suffer disease and most likely die. If we humans were to disappear the cows would definately die and it is because we have made them so dependant on us. Is this exactly fair? Who are we to select what they are and what they are supposed to look like? —The preceding unsigned comment was added by 194.83.25.10 (talk • contribs).

cleanup of this article

I did some cleanup of this article and removed the following text:

Controversially, profound examples of artificial selection are often said to be seen in humans themselves, who employ substantial cultural bias in mate selection, most obviously in the preference of human females for socially powerful mates - a factor which is not directly related to natural ecology or to simple secondary sexual characteristics. Critics of this view argue that sexual selection in all mammal species favors aggressive males, and that males of other primate species trade food for sex - and that aggression and food-gathering capacity are causally related to social power in any social species. This argues for a fuzzy line between ecological, artificial and sexual selection, especially in a highly cognitive and highly social species.

In many societies, institutions such as polygamy and the harem have served to permit some of the most successfully aggressive and logistically competent males to father drastically more offspring than others. Similar historical observations are made of harems of the Ottoman Empire and Siam, and of polygamy in Islam and among Mormons.

There is substantial controversy as to whether these are truly artificial selections, or examples of ordinary sexual selection, or even (when the economics predominate) natural selection, carried to extremes in human beings. Controversies of this sort lead some to make a careful distinction between ecological selection and sexual selection, i.e. to differentiate which of the two aspects of natural selection can be said to apply to humans in what circumstances, and what "artificial" aspects are perhaps "environmental" but neither naturally ecological nor wholly sexual.

Another way to resolve the controversy is to suggest that when humans act on humans, as when other animals act to select any of their own species as mate or when members of their species are harmed as a part of the mating rituals, the entire process should be considered part of sexual selection, and that only man acting on non-human species is a true "artificial" selection.

In this view, even such complex matters as economics may be considered wholly "sexual" (by certain green economists) or even wholly "natural" (by some anthropologists using the neoclassical political economy). This begins to intersect with Social Darwinism and fascism to a degree, both of which held that dominant human societies optimized, but did not alter, the fundamental factors driving selection of individuals to propagate a species.

Predictably, such assumptions also conflict with Marxist or feminist views which hold rather that an imposed political economy, i.e. capitalism (classical and neoclassical economics) or patriarchy/feudalism/militarism (as in the harem case above), are creating artificial conditions drastically at odds with what is of highest survival utility for the human species as a whole. But, as other cases of runaway sexual selection demonstrate, individuals or cliques within a species do not in general act for species-wide utility, and individuals and even whole species are sometimes extincted due to excesses of their species' sexual selection process. Were a Marxist or feminist view to predominate, then their shared humanism would be artificial selection.

Some believe the term artificial selection should be employed only to make a distinction between the human-chosen "artificial" factors and the combination of instinct and ecology that is "natural" without human choice. To describe more deliberate influences on human behavior they may refer to moral selection or ethical selection, e.g. as in the prison case.

These terms, too, often recur in moral philosophy and in arguments regarding influences on the evolution of societies deemed "desirable". The central focus in many religious traditions of suppressing sexual desire seems to suggest that what is usually deemed desirable for the society as a whole may well be exactly the opposite of what is desirable for the individual under normal natural selection, e.g. a human male who learns he has Human Immunodeficiency Virus could attempt to impregnate the maximum number of females hoping to have one born without the virus, or could choose to forgo sexual activity entirely due to the suffering it could cause. Or, alternatively, could choose to reveal the deficiency to partners, exactly the type of acquired trait that males in natural sexual selection would conceal. Removing oneself from the mating pool or drastically limiting mating choices in these ways would seem to constitute both morally sound and reasonably ethical behavior, and also clearly exemplify artificial selection.

However, most biologists and evolutionary theorists employ the term artificial selection only to make a distinction between the intentionally human-chosen "artificial" factors and the combination of instinct and ecology that is "natural" without human choice. To describe more deliberate influences on human behavior they may refer to sociobiology, moral selection or ethical selection.

... which is sort of POV-ish, poorly written, and not terribly useful. Anyone have an attachment to this text or some of the ideas it contains? Opabinia regalis 22:19, 13 June 2006 (UTC)

Merge from Selective Breeding

The selective breeding article covers the same topic as this article, but is confined to the scope of domesticated animals. I think selective breeding should redirect to this article, and the information from the present selective breeding article be merged in as a subtopic. Tarcieri 02:57, 31 July 2006 (UTC)

Given the content of selective breeding, I agree with you, but there's a long chain of merge proposals here - crossbreed into selective breeding and crossbreeding into crossbreed. I can't say I see much of value in the latter two, but one concern is that a number of dog breeding-related articles seem to link to them, and in those contexts a link to artificial selection might be a bit off track. Opabinia regalis 04:26, 31 July 2006 (UTC)

The actual breeding of domestic animals, while related, is certainly a topic unto itself. The specifics of dog and cat breeding are common enough in culture to merit their own articles, thus I don't think these should be merged. Artifical selection is more general and probably should be kept that way. If however, someone can think if a more descriptive name than selective breeding, I wouldn't object to that. The crossbreed and crossbreeding can go together, but should stay away from both artificial slection and selective breeding. I see no reason to merge selective breeding and artificial selection as I think it would make the topic too diverse to be comprehended. pschemp | talk 05:23, 31 July 2006 (UTC)

Ok, first, the merge tags were not set up correctly, but I fixed that. Second, the whole crossbreeding thing centers around hybridisation, maybe it should go visit articles in that topic area. However, it has little to do with the selective breeding or natural selection as hybridisation is not their main focus. That being so, I removed the crossbreeding from this merge proposal as it doesn't make sense, and was formatted incorrectly anyway. pschemp | talk 05:31, 31 July 2006 (UTC)

I merged Crossbreed and Crossbreeding and agree they should stay out of any article that results from this discussion. In general, regardless of the outcome, the cat/dog/etc breeding articles should stay distinct from the evolution-related articles. That said, selective breeding at the moment is a bit of a misnomer, because it's almost entirely about mechanisms for deliberate breeding of domesticated animals. That's half domestication and half artificial selection, but doesn't really cohere as a topic of its own. It's also slightly backwards that artificial selection is listed as one strategy for selective breeding, when conceptually selective breeding is a subtype of artificial selection. This might make a big mess since so many articles link to selective breeding, but if I were starting from scratch I'd redirect it to artificial selection and keep separate and expanded articles on cat breeding, dog breeding, etc. (Or maybe a general breeding of domestic animals article). Opabinia regalis 05:26, 1 August 2006 (UTC)

I'm thinking this through, but I think what you are running up against is a term used in the popular lexicon in a different manner than the scientific one. The other thing is that that breeding is not the same thing as selection, so just eliminating it by making it a redirect doesn't make sense. It is true that selective breeding uses artifcial selection, but as they aren't synonyms, one shouldn't redirect to the other. It is obvious from the muber and type of links that selective breeding in the popular use has a different meaning than a biologist might use. However, getting rid of it for that reason probably isn't the best idea. A few things link to it when really they should link to Artificial selection, but that can be easily cleaned up. Basically, A.S is the biological concept, and selective breeding is that concept in action. Many, many things refer to selctive breeding in the way that our article is written. I agree it needs to be cleaned up and straightened out, but I can't see a merge of the information being beneficial. More thoughts later. pschemp | talk 05:38, 1 August 2006 (UTC)

Okay, here's what I'd suggest then: Rename "Selective breeding" to "Selective breeding (domesticated animals)", then configure a redirect from "Selective breeding" to "Artificial selection" with a reason of:

This article discusses selective breeding in the context of biology. For its colloquial usage regarding household pets and farm animals, see selective breeding (domesticated animals).

That way both uses are covered, the redirect takes you to the biological usage of the term, and the dog/cat related articles can update their links accordingly. Is that a good solution? Tarcieri 09:04, 1 August 2006 (UTC)

Just caught up with this discussion again. I didn't look to break down the types of articles linking to selective breeding but I'd have to think the default would be to not do anything that would make dozens of domestic animal related pages have to change their links. I'm starting to think the best response is to put a disambig statement on selective breeding redirecting to artificial selection for the usage in evolutionary biology. Opabinia regalis 04:41, 5 August 2006 (UTC)

Well, I went ahead and removed the mergefrom/to tags and just put a disambiguation-type statement on the selective breeding page, since no one else did anything. Tarcieri 09:01, 9 September 2006 (UTC)

"genetic processes underlying..." wording

there is no real difference in the genetic processes underlying artificial and natural selection

I'd like to see the wording here altered a bit. While it may be true that the genetic material acted upon by selection is the same regardless whether the selection is 'artificial' or 'natural,' there are no "genetic processes underlying selection." That is, said "genetic processes," i.e. mutation and recombination, are independent of selection.

The intent of the quote is clear, and I accept it. As I read it, it is trying to say that both "types" of selection act upon the same substrate, and both result in evolution. True as can be. That said, such processes do not underly selection; rather, they independently and irreverently precede it.

Perhaps for some this is a paltry distinction; I see it as a cause worthy of a more discriminating phraseology. The notion that genetic variation is itself somehow an element of selection is a misapprehension which contributes to the subsequent and frequent misunderstanding (common among both laypeople and science-kinder) that selection is directional, and evolution fatalistic.

Eradicating this misconception has long been a focus of popularizers of evolution science like Stephen Jay Gould and Richard Dawkins (though the former much more than the latter), since it precludes what they (and many biologists) interpret as an extremely important corollary of evolution: a strong refutation of human-centric fatalism--that humans are a "pinnacle of evolution," that our species was "destined to arise." [note: This is a significant cornerstone to the belief held by Dawkins and many others now and before him, that evolution is an argument against the existence of God (or god or gods).] In essence: (a) without evolution, humans would not exist; (b) evolution lacks goals; therefore, (c) humans are not the achievement of a goal. [note: I have summarized this argument in such a way as to make its logical inadequacies clear. Despite its flaws, it is often presented, albeit in more obfuscating prose, by people-who-should-know-better of all stripes (my favorite figurehead is Dawkins, but he's put himself there, so I don't feel bad about it). The next time you hear it, please call them on it! Also, if you'd like to chat about why it is logically inadequate, and the more interesting and rigorous conclusions that can be drawn without making it, feel free to message me!]

Returning to the topic at hand... in summary: evolution includes selection AND processes which yield genetic variation; BUT selection DOES NOT include processes which yield genetic variation. The two processes are independent constituents of evolution.

That said, I propose (and, barring objection, will institute) the following change to the wording:

From: "It should be emphasized that there is no real difference in the genetic processes underlying artificial and natural selection"

To: "It should be emphasized that the genetic material ultimately acted upon by selection is the same whether the selection event is termed 'natural' or 'artificial'"

Thoughts? Vitriol? Sweet, sweet lovin'?

Cheers! Temptinglip 10:24, 22 December 2006 (UTC)

Hmm. I'm not a fan of the phrase 'genetic processes' (though I think I may be the original perpetrator). But I think your suggestion leaves out some of what the original is trying (failing) to express. It's not just that both processes operate on the same genetic material (that much is, or should be, blatantly obvious), but also that natural and artificial selection are not two different things. In 'artificial selection', human preferences and practices form part of the environment of an organism; it's not functionally distinct from any other species remodeling its environment. Opabinia regalis 05:12, 23 December 2006 (UTC)

I understand the importance of the distinction, but "artificial selection" and "natural selection" are different. The substrate on which they act, genetic material, is the same, but they are "two different things" for two key reasons.

Mechanism: Artificial selective pressure regularly exceeds (and by orders of magnitude) the low, stable thresholds common to natural selection. This is by no means simply a distinction by degree: modern population genetic models of evolution by natural selection--that is to say, modern evolutionary canon--regularly assume weak selection, both as an acceptance of empirical evidence (high values of selective pressure metrics are exceptionally rare), and because assuming strong selection results in major changes to the output of these models. Belyaev's foxes are a fantastic example of artificial selection's ability to produce both output and rate of change that would not occur given weak selection, and thus would be a curious exception to the rule if observed in nature.

Agency: Turning to a more philosophical realm, we have the issue of the agent of selection. Artificial selection, by definition, results from the work of an agent, a "selector," whereas natural selection... to phrase this carefully... requires only a selective environment, not a selective agent. [There are those who posit that natural selection is guided by supernatural forces of various descriptions, and my point about Dawkins was that even he, when pressed, admits that such direction is ultimately unfalsifiable (which is why he opts instead to employ arguments of improbability.)] I'm not sure where you're from, O. regalis (great username, by the way), but here in the United States (and other countries with popular evolution-denial movements) this is far from a trivial distinction.

My previous post was probably not as clear as it could have been, and also included the point that evolution and natural selection are non-synonymous (which is still important but irrelevant to the objection at hand). I agree with you, though, that my phrasing is weaker than what it replaced, and am certainly open to suggestions about how to accommodate for these important considerations while maintaining the strength and spirit of the original, so please feel free to suggest a revision! Temptinglip 06:46, 2 March 2007 (UTC)

Why, thank you; good usernames are in short supply these days ;) Much of this, though, is distinctions without differences. 'Agency' is a red herring here. Humans are animals, they have an impact on the environment experienced by other animals, and thus influence the reproductive outcomes in those populations. The process is in no way different because we're more organized about it or do it faster. That's like saying a chemical reaction that occurs in nature is fundamentally a different process than the reaction that occurs in a beaker with a synthetic catalyst. I agree that anything in the article should not misleadingly imply that the analogy runs the other way around, and that a 'selector' is a component of all selection processes. I don't have any good suggestions just yet, but I'll think about it. Opabinia regalis 08:16, 3 March 2007 (UTC)

Origin of Species quote

Quote from OriginOS: "Slow though the process of selection may be, if feeble man can do much by artificial selection, I can see no limit to the amount of change, to the beauty and complexity of the coadaptations between all organic beings, one with another and with their physical conditions of life, which may have been effected in the long course of time through nature's power of selection, that is by the survival of the fittest."

Darwin only used the phrase once. The phrase was not in use before he published it. How did Darwin formally establish that man is "feeble"? Feeble in relation to what. I am looking for something on par with http://en.wikipedia.com/Astronomia_nova where Kepler established the laws of planetary motion , which was used by Newton to derive calculus which led to the Fourier Transfrom without which the Internet would not exist. In what way did Darwin formally establish the concept of Artificial Selection. How did he derive it from first principles. Where did he establish the principle of SoFittest, Artificial Selection must be independantly specified because in the quote he seems to define AS in terms of SoF. He seemed to conflate Natural Selection, SoFittest, never making clear what is the distinction. Darwin did'nt formally define AS, and ever since everybody has simply assumed it to be somehow formally established like the Laplace Transform is established. Artificial has a pejorative meaning as his use of "feeble" indicates. And survival of the fittest is an obvious tautology. It should be deeply embarrasing for Evolutionists to keep on stating that those that are fit survive and those that are not fit won't.

TongueSpeaker 17:26, 18 March 2007 (UTC)

Differentiation with Eugenics

Maybe the article doesn't need it, but I do. My previous understanding of the terms Eugenics and Artificial selection were that they were the same. I've read the respective articles, and I'm not any clearer on this. Maybe someone could explain it?
Is it that Eugenics is Artificial Selection practiced on humans, and carries negative connotations? The negative connotations are easy to account for. Is this the only distinction? Eugenics isn't practiced on sheep, is it? Cheers.--The Chairman (talk · contribs) 08:40, 5 August 2007 (UTC)

Eugenics is a form of voluntary selective breeding to improve the quality of society, at least in Galton's sense. Artificial selection is much broader, including, for example, antibiotic resistance. Richard001 05:45, 7 October 2007 (UTC)

I don't know how voluntary it might be, I still remember the mentally challenged adults that spoke to my High School civics class and how they complained about being forcible sterilized. Hardyplants 12:31, 7 October 2007 (UTC)

Negative selection (artificial selection)

Can we merge this here? I don't see any logic splitting off something like this from an article as underdeveloped as this one. Richard001 23:00, 13 October 2007 (UTC)

lost picture

There's a misisng image on this page, info below:

File:Corn selection.jpg

Selective breeding transformed teosinte's few fruitcases (left) into modern corn's rows of exposed kernels (right). —Preceding unsigned comment added by Smartse (talk • contribs) 00:14, 5 March 2009 (UTC)

Who?

In the "Contrast to natural selection" section it says:

"Indeed, many evolutionary biologists view domestication as a type of natural selection and adaptive change that occurs as organisms are brought under the control of human beings."

Which evolutionary biologists say this?