This is an archive of past discussions about Evolution. 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.
Here’s an article arguing that bird lungs are superior to mammal lungs [1] . Well, evolution sometimes works that way. It fashions a solution that is simply good enough. And it does not backtrack later to fashion a perfect solution. Here is another article about the respiratory system of birds [2] .
A couple of weeks ago, Gnixon invited me to contribute to the article. Thank you very much for the compliment, but I have not yet found the sweet spot. My writing has been criticized for sounding too much like an essay. Well, I don’t think the writing should be all that difficult to read (afterall, our concepts here are difficult enough!). There is a sweet spot between formality and readability.
And, I’m even more convinced that our article should be longer. This is a major destination article. This might well be our best chance to describe, to explain, to teach. So, if you have found the sweet spot, or even if you feel you’re close, please contribute. I think we could easily use five straightforward examples of evolution working, a much longer history of life on earth, and a longer section on controversy, including claims on “irreducible complexity” about the hemoglobin molecule and bacteria flagellum. When creationists talk about such things, they are really doing us a favor. These are great examples we can discuss. They are bringing up puzzles which do in fact pique people’s interests. Let’s keep the discussion going. I’m thinking about two paragraphs on each topic, even if there is another wiki article that discusses it at greater length, we just include a link (much longer for history of life on Earth). Much too much of wiki is people simply linking together blue words. That’s just the skeleton of the article! We need people who will fill in with good description and explanation. Please talk just like you would to an interested high school or college student. And maybe toward the latter part of the article, allowing it to become more challenging, talk just like you would talking to a professional colleague who’s in a slightly different field and who’s sincerely interested, What’s the latest going on in evolutionary biology? Go ahead and tell us. I want a readable, teachable article. I want to read stuff, be reminded of what I already know, and then go a little bit further. For example, the part about Archaea, that’s a completely different taxonomy than what I grew up knowing (I graduated from high school in 1981). I would very much like having this spelled out in plain English, and the implications. I understand one thing that makes this early taxonomy so difficult is that bacteria swap DNA all the time.
I do appreciate everyone’s efforts. I realize just how hard writing is. I’m making suggestions the best I can, but do it your own way. FriendlyRiverOtter03:22, 27 April 2007 (UTC)
Evolution is "guided" by natural selection and other activities, it attributes no human "value" to anything that happens. I guess I find the word "superior" to be attribute a "value" to something that evolved for different reasons. Birds have extraordinary metabolism (think about flying for 2500 miles when birds migrate), and their lungs evolved to provide oxygen to that metabolism. Humans don't need that, and in fact, bird lungs would not provide enough oxygen for humans to have the massive brain that we do. So, in that case, our lungs provide a superior advantage for humans over birds. Orangemarlin05:10, 5 May 2007 (UTC)
Evidence of Evolution
The evidence of Evolution section does not explain why similar traits among different organisms should preclude independent creation of each design by a single designer. It only shows that it is unlikely that they evolved independently. It also uses the "fact" of vestigal organs as proof of common descent, but it does not prove that they are vestigal. --Ezra Wax22:44, 4 May 2007 (UTC)
Is there anything that would preclude a single omnipotent designer's being the explanation for any phenomenon at all? Is there anything that that hypothesis couldn't in principle explain? Seriously? If not, the hypothesis can't be considered truly scientific. See falsifiability. Schmitty12023:35, 4 May 2007 (UTC)
This article isn't about vestigial organs. If you click on the link for each of the three items, you can read more about their vestigial nature. Also the article Vestigial structure has excellent statements about vestigial organs. However, through the study of morphology and developmental biology, we can illustrate development of various organs and other anatomical features from one organism to another. For example, we can trace one muscle on a fish and how it now functions as the diaphragm of an air breathing mammal. It's really outside of this article to list everything, that's what links are for. As for the similar traits=a designer. Well, that would take pages to discuss. And evolution doesn't care about a designer. The designer is natural selection, and it is unguided. Anything else isn't science, and belongs in a religious discussion. Orangemarlin23:52, 4 May 2007 (UTC)
It is not just "similar traits", which sometimes occur by convergent evolution, it is the same and similar genes. What creationist rejects paternity tests based on shared genes, because, well no, the child may be an independent creation, that just happens to share half his genes with the alleged father. Creationism is untestable, ID is poorly formulated, and perhaps true at some level, but a rather useless and unproductive without any evidence, especially when evolution is useful and productive, and evidently retained by the most scientific forumulations of ID to explain most variation and speciation. --Africangenesis01:56, 5 May 2007 (UTC)
Darwin argued against "special [independent] creation" based on several things: homology, vestigial traits, suboptimal design, biogeographic regions, species ranges, and my favorite, the naturally hierarchical grouping order of all living things. From the first edition: "This tendency in the large groups to go on increasing in size and diverging in character, together with the almost inevitable contingency of much extinction, explains the arrangement of all the forms of life, in groups subordinate to groups... This grand fact of the grouping of all organic beings seems to me utterly inexplicable on the theory of creation." ----- I know your question was about homology, but homology is only one of several lines of evidence that reject "special creation" of each species independently. Note that Darwin never argued against the existence of a supreme being or creator, he only argued that species could not have been created individually, one-by-one. TxMCJ05:46, 6 May 2007 (UTC)
Mutations and other random changes in these genes can produce new or altered traits
Mutation discussion
The following discussion has been closed. Please do not modify it.
Where in the article is it establisged that mutations can produce new traits. i.e. traits that did not already exist in a recessive form. --Ezra Wax22:57, 4 May 2007 (UTC)
I don't understand your question, recessive and dominant traits are not related and interconvertable forms of the same trait, they are separate phenotypes of different mutations. TimVickers23:38, 4 May 2007 (UTC)
If you want to assume good faith, then assume it. Insinuating bad faith is never helpful; either act on the good faith you assume of others, or, if you think you have strong reason to doubt another's good faith, then file a report or take it to the user's Talk page. Constantly questioning everyone else's good faith based on hunches creates a hostile atmosphere. It doesn't even matter whether the person is genuinely acting on good faith or not. -Silence06:44, 5 May 2007 (UTC)
References 41, 42 and 43 seem to be what you are looking for. I've expanded the section on gene divergence a little. TimVickers00:03, 5 May 2007 (UTC)
Mutations may merely reproduce a gene that already existed, whether recessive or not. Don't get confused by the scale either, a "trait" may merely be a different shaped protein due to the coding change, or a different level of expression of other genes. What makes it so that much of the time the new organism works rather than breaks is the level of redundancy and homeostasis that organisms have. The duplication of genes represented by the contribution from each parent in sexual reproduction is only a small part of the redundancy. It is apparent from the genome sequences, that most of them have been duplicated many times, with what were originally proteins and enzymes that were mere redundant duplicates, over time, diverging into protein and enzyme "families", with different functions, and different levels and patterns of expression. This redundancy means that mutations are often not fatal, and that functional characteritics can drift and provide the variation for natural selection to operate upon. A mutated enzyme, might not function as well as the original, but this may be compensated for in several ways. The gene from the other parent may take up the slack. A homeostatic gene regulation mechanism, may up the expression of the mutated gene, so that it still gets the job done despite its lower efficiency. Other enzymes in the same family may still have been doing some of that enzymes work all along, and faced with with higher levels of the substrate, from the chief enzyme's lower activity, they take on more of the work. It is this redundancy that allows leaps across seamingly deleterious or non-functional gaps. In a sense it is sometimes the lack of new "traits" at the macro or lack of function level, that allows mutations to accumulate and eventually produce novel functionality.
The redundancy and the families of enzymes and genes have a lot of explanatory power. A lot of the side effects of drugs that effect only a smaller percentage of people are due to genetic variation. Another enzyme or receptor in the same family as the target, happens to have a more closely related shape to the target than what is "normal" for most people, it may have even mutated back to the original gene. The pattern of tissues effected is often revealing. Sometimes it is the shape of the drug, that determines which other members of the enzyme or receptors in the same family are also interacted with. Thus different drugs in the same class can have different patterns of side effects. For instance viagra cross reacts with related enzymes in the heart and retina more than levitra which cross reacts more with nasal and sinus and stomack lining members of the enzyme family. Pick your "poison" or design a more selective/specific drug. Hope this helps.--Africangenesis07:13, 5 May 2007 (UTC)
Yep. Susumu Ohno in the 70's, regarding the evolution of novel gene function in vertebrates: "Redundancy created, selection merely modified". TxMCJ05:14, 6 May 2007 (UTC)
These concepts are not well represented in the article. I'm not sure where they would go. There is a redundancy benefit to both sexual reproduction, and to duplication of parts of the genome. The topic of elimination of deleterious mutations is discussed, but also important is the retention of deleterious mutations allowed by redundancy, to someday become beneficial, or part of a beneficial combination. In a sense, any duplication of genes, or retention of a less functional gene, can be considered at least temporarily deleterious, since it consumes resources without being as good as the predecessor. The role of hormesishomeostasis in allowing the retention/toleration of deleterious genes is also not in the article. The development of hormesishomeostasis is probably every bit as important a force in evolution as the development of sexual reproduction. Perhaps rather than a force in evolution, hormesishomeostasis should be considered a powerful enabler, allowing the gaps that so intrigue ID advocates to be bridged, deleterious changes in "irreducibly complex" components to be survived. --Africangenesis07:59, 7 May 2007 (UTC)
I agree that gene and genome duplications constitute an important part of evolutionary history (I always give one to two full lectures on this topic in my college Evolution course)... but I'm not sure whether we ought to give it much more than passing mention here, because that concept can quickly get complex (gene families, orthology/paralogy, etc.) Redundancy is really more specific to topics like genome evolution and the evolution of novel gene function, but it probably belongs here as well, in part. TxMCJ09:44, 7 May 2007 (UTC)
Article looks great
This is the best the article's looked in my experience of seeing it. While going through and making a bunch of minor edits last night and today (mainly for clarity and accuracy), it was clear that somehow this article has undergone a massive improvement over the past few weeks. Kudos to the editors, and now let's hope that for the most part, we have the wisdom to "leave good enough alone". :-) TxMCJ17:38, 6 May 2007 (UTC)
Maybe we should nominate it for FA status once again! You and Tim Vickers did a lot of "science" work on the article, it reads well (considering the number of editors), the POV edits from a certain POV editor have been reverted or toned down, and it includes everything but the academic categories or whatever it was called that Silence wants. Orangemarlin16:21, 7 May 2007 (UTC)
Good idea. If nothing else, the article is testament to the possibility of achieving even temporary success and article quality, even in the most socially volatile subject areas, and even with an army of new editors, POV-pushers, and vandals coming and going all the time. Vigilance, article custodianship, and strict adherence to scientific standards have paid off -- at least for the time being. TxMCJ16:52, 7 May 2007 (UTC)
Thanks for the feedback, but this is still work in progress. "Evidence of evolution" and "Evolutionary history of life" are still under-referenced for a FAC. I'm also intending to add a discussion of current areas of research in evolution, as outlined in the talk section above. TimVickers17:06, 7 May 2007 (UTC)
Points taken -- I'm just complimenting the progress this article has made over the past month or so. With all due respect to prior editors, it was really kind of a mess in early April. TxMCJ17:50, 7 May 2007 (UTC)
developmental biology and homology?
Traditionally shared or primitive characteristics and development in embryos have been pointed to as evidence for evolution. We probably don't need this now, since it doesn't really add anything to the huge body of evidence, since we are so reductionist to gene and molecular level. However, shouldn't this be included for historical purposes at least? Even the evidence for common descent article barely mentions it.--Africangenesis08:15, 8 May 2007 (UTC)
Apropos, I think the article on embryology could benefit from some development. I am no expert and not competent to work on it, but perhaps some pf you active on this page can help improve that article. We spend a lot of (constructive) time improving this article - but sometimes important linked articles are neglected ... Slrubenstein | Talk12:01, 8 May 2007 (UTC)
The evidence for evolution section should be deleted. How many times do we need to remind people of this? The section was already renamed before following a discussion, but Orangemarlin apparently wasn't paying any attention to the ongoing discussions and, out of confusion, reverted a lot of in-progress changes during a lull. An "evidence" section is a completely inane idea, because everything in biology is, in one way or another, "evidence" for evolution. The reason the "evidence" section needs to be deleted is the same reason that Evidence of evolution was recently changed to Evidence of common descent: a discussion of "evidence" is integral to every aspect of evolution, so it should, properly, be discussed in the relevant section instead. For example, the evidence for mutation should be discussed under Evolution#Mutation; the evidence for speciation should be discussed under Evolution#Speciation and exinction; the evidence of common descent should be discussed under Evolution#Common descent; etc.! A single centralized section for "evidence" makes as little sense as having a single centralized section for "theories" or for "facts". That is why the "evidence" section was in the process of being shortened and reorganized into "Homology" and "Phylogeny" subsections of the new "Common descent" oversection (in this order: "Common descent" lead, "Homology" (encompassing both anatomical and molecular homologies), "History of life" (including a paragraph on abiogenesis), and "Phylogeny and systematics" (integrating information on the relationships between organisms, formerly discussed in a variety of other sections). The fact that this reorganization was reverted before it could be finished, while the editors who had been working on it were taking a break, is purely and simply an error—and a truly ridiculous one. -Silence23:49, 8 May 2007 (UTC)
By the way, if you consider this is a reversion, then I'm guilty. If I change the name of section, because it wasn't clear what it was representing, then that's hardly a reason for your attack above. Orangemarlin00:34, 9 May 2007 (UTC)
Orangemarlin is a valuable editor, and I'm sure he didn't mean to backpedal on this. In principle I agree with Silence's point, that "evidence" should be distributed within relevant sections... although for folks who truly need a quick-and-dirty education in Evolution, condensing all of it in one section can be helpful. I can see it going either way. Also, I have never been too fond of the word "evidence" in this context, because it sort of implies a kind of detective-guesswork thing, which science really isn't. Scientists also rarely use the phrase "evidence of evolution" and are more apt to use phrases like "evolutionary patterns in:" genomes, homology, phylogenetics, the fossil record, whatever. Anyway, both Silence and Orangemarlin have proven themselves to be valuable, objective, and non-POV editors, so it will be nice to see "everyone getting along" again soon (remember when you were all tapping your feet waiting for me to quit arguing with Gnixon?) Peace, TxMCJ07:31, 9 May 2007 (UTC)
This is slightly off topic, but I wanted to address this article. Considering Evolution is the foundation of Biology, the quality of Evolution far surpasses the article on Biology. Moreover, Biology should be the core article for everything else about biology in Wikipedia, yet it is poorly written, barely referenced, and makes a poor reference source for all of the better articles on Wiki. If any of you have time, please head on over and edit if you can. I know the Evolution/Creation articles are about 7 full time jobs, but Biology needs help. Orangemarlin16:03, 9 May 2007 (UTC)
Perhaps your comment is badly phrased OM? Evolution is fundamental for the current understanding of major parts of modern biology but without evolutionary theory parts of biology would still be valid and topics about microscopy or organismal vs cell theory could be validly discussed without an understanding of evolution (although with it some discussions would inevitably be enhanced).
However, this point aside I will look at the bio page and if it lacking then well spotted ....Candy16:16, 9 May 2007 (UTC)
Well, partially poorly worded, but really without Evolution, the Earth would be filled with a chemical soup, maybe with some one-celled bacteria, all of the same species, lying around. And Wikipedia wouldn't exist. George W. Bush would never have stolen the election in Florida. And the New York Yankees will never win a World Series EVER. I digress. My point is that yes, if Creationists are right (and then I have a lot of apologies to make), Biology would still be an important science. But without Evolution, nothing would exist biologically speaking. Or it would be quite dull (with just one species of Bacteria), but we wouldn't be around to care. That's about as philosophical I can get without an additional cup of coffee this morning. Orangemarlin16:38, 9 May 2007 (UTC)
For such an important article, I think we should put this through another round of peer-review before submission as a FAC. I'll try to get some input from experts in the field as well, scientists working in this area tend to recognise the importance of communicating with the public. TimVickers22:23, 9 May 2007 (UTC)
Evolution FAQ: Level of Acceptance of Evolution among Scientists
Old discussion on Poll
The following discussion has been closed. Please do not modify it.
First let me say that I am not a creationist or ID advocate--I am trying to evaluate both sides skeptically like a good critical thinker. I have a problem with the part in the Evolution FAQ on this talk page that says, "Evolutionary theory is not controversial in biology itself, where more than 99.84% of scientists accept it.[1][2]" Cited are references to a Gallup poll of scientists. Firstly, these are tertiary and secondary sources, respectively, the first referring to the second. Secondly, because of that I cannot know exactly what question was asked. Roughly 99.84% of American scientists may reject "creation-science," but that study was taken 20 years ago, and in that time ID has risen. ID (officially) is neither creation-science nor evolution. Furthermore, did that 99.84% actually reject all creation science or just YECism (which was making public splashes at that time, as in McClean vs. Arkansas)? The Newsweek author might not have realized the difference. I would just clip that statement out, but then there would be nothing left, so someone would probably revert me. I don't doubt that a significant majority of scientists are pro-evolution (just peel open any science journal). Does anyone wish to provide further evidence in defense of this poll, or a different meter of scientific acceptance? Otherwise, that statement needs to be revised or cut. Good day. Schmitty12000:26, 3 May 2007 (UTC)
I would also note that polls are completely meaningless in science. No scientific consensus is ever reached by voting or polling, it is reached by data, hypothesis testing, and familiarity with the total evidence. There was a time in History when Darwin and Wallace were the only two scientists on Earth who "believed in" (or even understood) Evolution. But being in the 0.00001% minority at that time didn't make their conclusions less true. TxMCJ05:25, 6 May 2007 (UTC)
It would be interesting to know how the poll was first reported, I doubt the article even has the actual question asked. You would be doing a service if you get the article from the library. If you are trying to evaluate the sides skeptically go to the evidence, not the polls. I'm also not sure what the other side of "both sides" would be. The hypothesis that other life forms are closely related and share lots of genes with us and each other has been confirmed thousands of times. The Intelligent Design folks are more concerned about proving the existance of the designer/god than in acquireing a practical understanding of nature. Keep in mind that humans are intelligent enough to probably be within a century or so of being able to design new life forms ourselves, and we've achieved that in just a few thousand years of civilization, and only about a hundred thousand years since modern humans first emerged in Africa. Given a longer time period to accumulate technology and understanding, the actual intelligent designer might not have to be as intelligent as us. We human critters seem to have some logical fallacies wired into our brains, thus you see people who consider themselves scientist types, clinging to polls and consensus like the deprived monkeys clinging to their wire "mothers". Religiousity is so common that it must be considered "normal". I am at peace with that.--Africangenesis06:10, 3 May 2007 (UTC)
Yeah, I know, evidence is better than polls. I was just making my position on this subject clear. Regardless, for Wikipedia purposes, I still think we need a better meter of scientists' acceptance of evolution, since anti-evolution views are getting kept off this page on the premise that there is virtually no controversy among reliable sources (earth and life scientists) regarding evolution. As Orangemarlin says, polls are evil. I will try to get the article from the library...actually, the original Gallup poll itself would be best. I can't find it on their website. If the poll needs to be dropped, I suggest as alternatives the lack of peer-reviewed anti-evolution articles in respectable journals and the rejection of creationism and ID by respectable scientific societies like AAAS and NAS, as pointed out. Good day. Schmitty12014:01, 3 May 2007 (UTC)
The reason anti-evolution views are kept off this page is because there is no anti-evolution view yet proposed that is scientific. "Virtually no controversy among reliable sources" is given as a factual statement, not as a justification for excluding anti-evolution views. There is really no issue about "scientists' acceptance of evolution" because no core elements of evolutionary theory have ever been falsified via experiment or data. Scientific "acceptance" is not a matter of personal opinion, it is a matter of rational and repeatable analysis of hypotheses and measurable data. Any "scientist" who doubts the veracity of Evolution is either unfamiliar with the data and the evidence, or else is a lousy scientist. TxMCJ05:31, 6 May 2007 (UTC)
Searching abstracts is not very good methodology, only those on a mission, like global warming alarmists, would go out of their way to relate their particular result to the grand theories, in the abstract, as opposed to the discussions or the conclusions in the full text. Far more problematic for ID theory, is not the evidence for evolution, but for a much stronger competing theory that unfortunately doesn't have a simple screen for finding the support in the abstracts, and that is the theory of "really stupid design", the results that make one ask "why the heck did evolution do that!", or lament "too bad evolution did that", or "doesn't evolution like us?". If you've ever lost a loved one to disease, or had a lost limb fail to grow back, or had to pierce your ear due to designer shortsightedness, you know what I mean. Wouldn't it be ironic if the ID proponents defeated the evolutionary theory, only to lose to the "really stupid design" theory in the end. If you think being a monkey's uncle is bad, try having to worship the monkey instead.--Africangenesis17:31, 3 May 2007 (UTC)
This is nonsense. The reality is that ID isn't science, which is why it doesn't appear in articles. Its also worth noting that the articles it does appear in are of two sorts: those which dismiss ID, and those which use it in reference to something entirely different (namely, intelligently designing objects in engineering). There is no evidence for ID, and there are pilees and piles and piles of it for evolution. Evolution is actually self-evident if you understand molecular biology or really just observe creatures and the fossil record; it is obvious that it occurs. Genetics alone prove it beyond all doubt. Titanium Dragon01:15, 4 May 2007 (UTC)
OK, the ID people are never going to "defeat" evolutionary theory, because ID isn't science. Until it is science, then it has no standing in a discussion about the science of evolution. "Global warming alarmists"--oh you must be referring to all of the scientists who believe that there is sufficient evidence that the earth is warmer than 100 years ago (although I could debate the reasons behind it). This is not a useful discussion, because ID has no place in science. Orangemarlin18:14, 3 May 2007 (UTC)
No I was referring to the scientists, who think they can attribute and project the recent warming, with models that can "match" the 20th century climate, while having a factor of two difference in climate sensitivity, and when ALL the models have a correlated surface albedo bias against solar that averages more than 4 times the global energy imbalance, and another 10 times larger than the accuracy needed to attribute that imbalance, and are still "confident" in the face of solar activity that for 60+ years has been at one of the highest levels of activity in the last 7000 years, in a system where the thermal inertia of the oceans delays equilibration to a new level of forcing for centuries. I don't know whether the GHG contribution is closer to 20% or 80%, and neither does anyone else. Join us at Global warming.--Africangenesis18:38, 3 May 2007 (UTC)
Okay, I have a microfilm of that Newsweek article on hold at my local library. It might take a while to get here, though; I live in a small town. I searched on Gallup's website, but I couldn't find an open-access poll about the level of acceptance of evolution among scientists. You need a subscription to get into much of their survey data. Meanwhile I'm going to modify the FAQ slightly to make it more accurate. Cheers. Schmitty12019:56, 3 May 2007 (UTC)
If the article doesn't disclose the question and enough info to properly qualify and assess the poll, I will support removal or severe de-emphasis of the oft quoted text. -- thanx for your good faith effort.--Africangenesis20:50, 3 May 2007 (UTC)
I think your agenda is obvious here. We haven't seen the article yet. No real surprise though, given the typical activities of creationists in such articles. Titanium Dragon01:24, 4 May 2007 (UTC)
Are you talking to me? If so, I have no "agenda." I've raised what I believe are legitimate concerns regarding the way this statistic is being used on Wikipedia: it's out of date, it's quoted from a tertiary source, and it's not clear whether all of anti-evolution or just YECism is being talked about. The best way to resolve them would be to find the original Gallup survey, or failing that, to find the Newsweek article and see if they can be resolved by looking at the context. You haven't seen the Newsweek article yet because, like I said, it's on hold. I won't hold it against you if you remain skeptical, but I will eventually post up the greater context of that oft-cited reference. Unfortunately the librarian said it might take some time (possibly weeks). If you have easier access to this issue, please post up the context in which the phrase "By one count there are some 700 scientists with respectable academic credentials (out of a total of 480,000 U.S. earth and life scientists) who give credence to creation-science..." occurs. I think the surrounding paragraph will do. Good day. Schmitty12003:08, 4 May 2007 (UTC)
Yeah, that old canard was blown out of the water years ago. That comes from some Discovery Institute study that got some 2 or 3 hundred "scientists" to state they supported creation. Of course, most of these folks weren't scientists (in this case we mean someone who studies one of the natural sciences like chemistry, biology or physics, not an applied science like engineering...applied scientists have no more knowledge of evolution than an average person on the street). Project Steve is much more interesting in showing support of Evolution. I think there are now over 700 Steve's in the sciences who signed off in support of Evolution. I'm willing to grant that there are less than 0.5% of scientists who are clueless and support creationism. That's infinitely better than the 50% of Americans who believe in Alien abduction, Sasquatch, Area 52, and whatever other myths out there. Orangemarlin05:13, 4 May 2007 (UTC)
I wasn't actually talking to you Schmitty. Sorry for the confusion. If we can't track this one down, there's the possibility of using other studies. There's virtually no support for creationism among scientists, and even less among biologists, which should come as a surprise to no one - creationism is, after all, not science, and biologists can't be competant if they're creationists because you simply can't do a lot of your work without evolution as a framework. It'd be like being a chemist and rejecting atomism, or a physicist and rejecting elecromagnetism. Titanium Dragon07:19, 4 May 2007 (UTC)
Once again, the number and/or percentage of scientists "accepting" Evolution is a completely irrelevant measure of its veracity. The fact that the vast majority of scientists DO accept evolution doesn't speak to the truth of Evolution, as much as it speaks to the fact that most scientists are good scientists. TxMCJ05:36, 6 May 2007 (UTC)
Yes, I agree, scientific truth is not determined by polls, but Wikipedia's criteria for inclusion in articles involve NPOV, verifiability, no original research, and the use of reliable sources. Truth does not come into play except when establishing if a given text violates these policies. Therefore, unless it can be shown that the scientific consensus in favor of evolution is truly overwhelming, anti-evolution views should be given some attention on this page. In point of fact I am inclined to believe that it is indeed the overwhelming scientific consensus, and that per established policy anti-evolution views should be kept off this page. However, the poll is still out of date, it's still quoted from a tertiary source, and it's still equivocal on exactly what is being addressed. Good day. Schmitty12016:16, 6 May 2007 (UTC)
Sorry, I have to disagree with your argument that EVEN if there were no documented consensus among general scientists, that therefore attention to anti-evolution views is justified. This is because there IS NO scientific alternative to Evolution, so any "anti-evolution views" would necessarily be non-scientific in the first place. I don't know why you are invoking the Wikipedia inclusion standards, since Evolution is clearly not a POV, the data are verifiable, and the literature of reliable sources is vast. If you are arguing that the citation here of the poll is not verifiable or reliable, you might be able to make a case for that, but please understand this: even if the poll were a total fabrication, it does not therefore mandate inclusion and attention to nonscientific views. The fact that such a poll may or may not exist has ABSOLUTELY NO BEARING on the content that belongs in this article, and the content that does not. TxMCJ16:46, 6 May 2007 (UTC)
I very much hear you saying that you believe that there is no scientific alternative to evolution. But unless you can show that anti-evolution views are such a tiny minority among those who work in the relevant field, that including them would violate Undue Weight in NPOV, then it is still just your opinion. I agree that some poll would not be the only way to show that it is indeed the case that evolution is the overwhelming scientific consensus. The literature supporting evolution is indeed vast and verifiable. So I agree that we can still present evolution as a proven fact if it can be shown that there are no reliable sources opposing it. I'm worried about just one difficulty, though: who gets to say what is and is not a "reputable" scientific journal or society? I already edited the FAQ to point out that numerous "respectable" scientific societies are in support of evolution, but in retrospect, perhaps it would have been more honest for me to not do that so quickly. Schmitty12014:23, 7 May 2007 (UTC)
Schmitty, c'mon. There are literally no more than a handful of papers which anti-evolution proponents even try to claim constitute peer reviewed papers against evolution. If that isn't enough, I don't know what is. That and the presence of the massive number of scientific societies supporting evolution, and also Project Steve should be more than enough. JoshuaZ14:40, 7 May 2007 (UTC)
It is not my "opinion" that there is no scientific alternative to Evolution that explains the data. There is -- factually -- no scientific alternative to Evolution that explains the data. You cannot point me to it, and neither can anyone else. It does not exist. That is not an opinion and it is not a POV. Please review the definition of science. TxMCJ16:00, 7 May 2007 (UTC)
And it concerns me that there is, once again, an editor around here arguing this kind of point. TxMCJ15:56, 7 May 2007 (UTC)
All right then. Suppose that we revise that part in the FAQ to say that the statements of major scientific societies and Project Steve show that scientists are overwhelmingly pro-evolution, and that if someone can find a reliable source challenging evolution, then this could be included in the article, but until then, the page must reflect scientific consensus. This would place burden of proof on any passing creationists or ID advocates to show that there is any challenge to evolution by serious scientists. Would anyone object to that? Schmitty12023:09, 7 May 2007 (UTC)
All of this is already implied by nature of the fact that this is a science article. And BTW, it's not "finding a reliable source challenging evolution" that would make a difference, it's finding an "alternative falsifiable theory that explains the available data and does not invoke the supernatural" that would be needed. And it surprises me that you, as a self-claimed high school student who still has so much to learn in this world, would be arguing so passionately for this type of edit to the article or the FAQ. Just a little warning: it sure sounds like an agenda and POV-pushing to me. TxMCJ23:24, 7 May 2007 (UTC)
<reduce indent> OK Schmitty120, I don't think anyone, not me or any other editor, would be opposed to a reliable, verifiable, and peer-reviewed source challenging Evolution. Of course, the undue weight clause of neutral point of view would suggest that even mentioning one article challenging Evolution is not appropriate, because the 9 million other articles would not only be the consensus, but it would be the Neutral and Scientific POV. By the way, scientists are not overwhelmingly pro-Evolution as a matter of faith, they are overwhelmingly pro-Evolution because it is science. Orangemarlin23:22, 7 May 2007 (UTC)
To Orangemarlin: Point taken about Undue Weight, and I hope you're right about scientists. To TxMCJ: I don't understand what your problem is. First let me stress that I am talking about what should be done on this article, not in the scientific community. I agree wholeheartedly that scientists such as yourself should not accept an alternative theory unless it is truly superior. But if it were the case that there were any significant number of reliable sources opposing evolution, then Wikipedia would have to give them some weight in accordance with NPOV. I do not believe this is the case.
This is why you're wrong: even if ten million "reliable sources" opposed evolution, opposition without presenting a scientific alternative or without scientifically sound criticism of the current science, is garbage. Again: "reliable sources" is not what would be needed to present an alternative scientific theory. An alternative scientific theory is what would be needed. This alternative scientific theory does not exist. Thus, polls, opinions, percentages, and number of "reliable sources" are irrelevant. In the absence of a scientific alternative you cannot even begin to discuss a scientific alternative. Opposing something without offering up a reasonable alternative is not intelligent, and it is certainly not science. TxMCJ17:51, 8 May 2007 (UTC)
I am not pushing a POV. My proposed revision to the FAQ is essentially a paraphrase of what JoshuaZ said. If you guys really think it is trite or too generous to the creationists, then fine, I'll drop it. It's really not that important. Good day. Schmitty12013:57, 8 May 2007 (UTC)
Smitty120, I thought you were questioning the quality and methodology of a poll, now reading up above, it sounds like what you really wanted was to get some "By one count ..." statement into the FAQ, from that same article? The start of that "By one count ..." statement, makes me skeptical of whether the article will elaborate on how exactly they arrived at that "one count", what questions they asked, etc. Why would that statement make a difference? --Africangenesis14:46, 8 May 2007 (UTC)
All right everyone. I really was acting in good faith, but you've all convinced me that I've gone in over my head. I'm going to drop the whole issue. I extend my most humble apologies to everyone whom I've aggravated. Have a nice day, and good luck on future editing. Schmitty12021:40, 8 May 2007 (UTC)
Another important fact is that in Australia as far as I know the ID topic is not as highly debated as in the States, there is few instances of it comming up it the scientific field and evolutionary debate. So is this all an American debate on the topic or what? It should be sourced and put in an article on the subject. Enlil Ninlil05:34, 4 May 2007 (UTC)
Well, it happens in other countries, but the USA is filled with a small group of individuals that has a goal of making the USA into a "Christian" country. They voices have drowned out reason, and they make forays into government institutions, like schools, to force their vision of the world, that is Creationism. Lucky for the USA, we have a strong court system, even after being dominated by the far right for the past six years, that is still a voice of reason, and in nearly every case, the religious right loses. Lucky for those same individuals, when they go see their doctors, all of their medicines are invented, developed, perfected, and studied by scientists who not only firmly believe in Evolution, they know they can attack medicine because they understand Evolution. Of course, most of those physicians believe in Evolution. But we Americans have one advantage over you Australians--we don't have to figure out the rules for Cricket, leaving us more time to battle the creationists. 06:53, 4 May 2007 (UTC)
Thats because we are trying to figure out the rules of baseball. But still the evoultion theory is not strongly challenged here. Enlil Ninlil23:27, 7 May 2007 (UTC)
Evidence of Evolution
The evidence of Evolution section does not explain why similar traits among different organisms should preclude independent creation of each design by a single designer. It only shows that it is unlikely that they evolved independently. It also uses the "fact" of vestigal organs as proof of common descent, but it does not prove that they are vestigal. --Ezra Wax22:44, 4 May 2007 (UTC)
Is there anything that would preclude a single omnipotent designer's being the explanation for any phenomenon at all? Is there anything that that hypothesis couldn't in principle explain? Seriously? If not, the hypothesis can't be considered truly scientific. See falsifiability. Schmitty12023:35, 4 May 2007 (UTC)
This article isn't about vestigial organs. If you click on the link for each of the three items, you can read more about their vestigial nature. Also the article Vestigial structure has excellent statements about vestigial organs. However, through the study of morphology and developmental biology, we can illustrate development of various organs and other anatomical features from one organism to another. For example, we can trace one muscle on a fish and how it now functions as the diaphragm of an air breathing mammal. It's really outside of this article to list everything, that's what links are for. As for the similar traits=a designer. Well, that would take pages to discuss. And evolution doesn't care about a designer. The designer is natural selection, and it is unguided. Anything else isn't science, and belongs in a religious discussion. Orangemarlin23:52, 4 May 2007 (UTC)
It is not just "similar traits", which sometimes occur by convergent evolution, it is the same and similar genes. What creationist rejects paternity tests based on shared genes, because, well no, the child may be an independent creation, that just happens to share half his genes with the alleged father. Creationism is untestable, ID is poorly formulated, and perhaps true at some level, but a rather useless and unproductive without any evidence, especially when evolution is useful and productive, and evidently retained by the most scientific forumulations of ID to explain most variation and speciation. --Africangenesis01:56, 5 May 2007 (UTC)
Darwin argued against "special [independent] creation" based on several things: homology, vestigial traits, suboptimal design, biogeographic regions, species ranges, and my favorite, the naturally hierarchical grouping order of all living things. From the first edition: "This tendency in the large groups to go on increasing in size and diverging in character, together with the almost inevitable contingency of much extinction, explains the arrangement of all the forms of life, in groups subordinate to groups... This grand fact of the grouping of all organic beings seems to me utterly inexplicable on the theory of creation." ----- I know your question was about homology, but homology is only one of several lines of evidence that reject "special creation" of each species independently. Note that Darwin never argued against the existence of a supreme being or creator, he only argued that species could not have been created individually, one-by-one. TxMCJ05:46, 6 May 2007 (UTC)
Mutations and other random changes in these genes can produce new or altered traits
Mutation discussion
The following discussion has been closed. Please do not modify it.
Where in the article is it establisged that mutations can produce new traits. i.e. traits that did not already exist in a recessive form. --Ezra Wax22:57, 4 May 2007 (UTC)
I don't understand your question, recessive and dominant traits are not related and interconvertable forms of the same trait, they are separate phenotypes of different mutations. TimVickers23:38, 4 May 2007 (UTC)
If you want to assume good faith, then assume it. Insinuating bad faith is never helpful; either act on the good faith you assume of others, or, if you think you have strong reason to doubt another's good faith, then file a report or take it to the user's Talk page. Constantly questioning everyone else's good faith based on hunches creates a hostile atmosphere. It doesn't even matter whether the person is genuinely acting on good faith or not. -Silence06:44, 5 May 2007 (UTC)
References 41, 42 and 43 seem to be what you are looking for. I've expanded the section on gene divergence a little. TimVickers00:03, 5 May 2007 (UTC)
Mutations may merely reproduce a gene that already existed, whether recessive or not. Don't get confused by the scale either, a "trait" may merely be a different shaped protein due to the coding change, or a different level of expression of other genes. What makes it so that much of the time the new organism works rather than breaks is the level of redundancy and homeostasis that organisms have. The duplication of genes represented by the contribution from each parent in sexual reproduction is only a small part of the redundancy. It is apparent from the genome sequences, that most of them have been duplicated many times, with what were originally proteins and enzymes that were mere redundant duplicates, over time, diverging into protein and enzyme "families", with different functions, and different levels and patterns of expression. This redundancy means that mutations are often not fatal, and that functional characteritics can drift and provide the variation for natural selection to operate upon. A mutated enzyme, might not function as well as the original, but this may be compensated for in several ways. The gene from the other parent may take up the slack. A homeostatic gene regulation mechanism, may up the expression of the mutated gene, so that it still gets the job done despite its lower efficiency. Other enzymes in the same family may still have been doing some of that enzymes work all along, and faced with with higher levels of the substrate, from the chief enzyme's lower activity, they take on more of the work. It is this redundancy that allows leaps across seamingly deleterious or non-functional gaps. In a sense it is sometimes the lack of new "traits" at the macro or lack of function level, that allows mutations to accumulate and eventually produce novel functionality.
The redundancy and the families of enzymes and genes have a lot of explanatory power. A lot of the side effects of drugs that effect only a smaller percentage of people are due to genetic variation. Another enzyme or receptor in the same family as the target, happens to have a more closely related shape to the target than what is "normal" for most people, it may have even mutated back to the original gene. The pattern of tissues effected is often revealing. Sometimes it is the shape of the drug, that determines which other members of the enzyme or receptors in the same family are also interacted with. Thus different drugs in the same class can have different patterns of side effects. For instance viagra cross reacts with related enzymes in the heart and retina more than levitra which cross reacts more with nasal and sinus and stomack lining members of the enzyme family. Pick your "poison" or design a more selective/specific drug. Hope this helps.--Africangenesis07:13, 5 May 2007 (UTC)
Yep. Susumu Ohno in the 70's, regarding the evolution of novel gene function in vertebrates: "Redundancy created, selection merely modified". TxMCJ05:14, 6 May 2007 (UTC)
These concepts are not well represented in the article. I'm not sure where they would go. There is a redundancy benefit to both sexual reproduction, and to duplication of parts of the genome. The topic of elimination of deleterious mutations is discussed, but also important is the retention of deleterious mutations allowed by redundancy, to someday become beneficial, or part of a beneficial combination. In a sense, any duplication of genes, or retention of a less functional gene, can be considered at least temporarily deleterious, since it consumes resources without being as good as the predecessor. The role of hormesishomeostasis in allowing the retention/toleration of deleterious genes is also not in the article. The development of hormesishomeostasis is probably every bit as important a force in evolution as the development of sexual reproduction. Perhaps rather than a force in evolution, hormesishomeostasis should be considered a powerful enabler, allowing the gaps that so intrigue ID advocates to be bridged, deleterious changes in "irreducibly complex" components to be survived. --Africangenesis07:59, 7 May 2007 (UTC)
I agree that gene and genome duplications constitute an important part of evolutionary history (I always give one to two full lectures on this topic in my college Evolution course)... but I'm not sure whether we ought to give it much more than passing mention here, because that concept can quickly get complex (gene families, orthology/paralogy, etc.) Redundancy is really more specific to topics like genome evolution and the evolution of novel gene function, but it probably belongs here as well, in part. TxMCJ09:44, 7 May 2007 (UTC)
Article looks great
This is the best the article's looked in my experience of seeing it. While going through and making a bunch of minor edits last night and today (mainly for clarity and accuracy), it was clear that somehow this article has undergone a massive improvement over the past few weeks. Kudos to the editors, and now let's hope that for the most part, we have the wisdom to "leave good enough alone". :-) TxMCJ17:38, 6 May 2007 (UTC)
Maybe we should nominate it for FA status once again! You and Tim Vickers did a lot of "science" work on the article, it reads well (considering the number of editors), the POV edits from a certain POV editor have been reverted or toned down, and it includes everything but the academic categories or whatever it was called that Silence wants. Orangemarlin16:21, 7 May 2007 (UTC)
Good idea. If nothing else, the article is testament to the possibility of achieving even temporary success and article quality, even in the most socially volatile subject areas, and even with an army of new editors, POV-pushers, and vandals coming and going all the time. Vigilance, article custodianship, and strict adherence to scientific standards have paid off -- at least for the time being. TxMCJ16:52, 7 May 2007 (UTC)
Thanks for the feedback, but this is still work in progress. "Evidence of evolution" and "Evolutionary history of life" are still under-referenced for a FAC. I'm also intending to add a discussion of current areas of research in evolution, as outlined in the talk section above. TimVickers17:06, 7 May 2007 (UTC)
Points taken -- I'm just complimenting the progress this article has made over the past month or so. With all due respect to prior editors, it was really kind of a mess in early April. TxMCJ17:50, 7 May 2007 (UTC)
developmental biology and homology?
Traditionally shared or primitive characteristics and development in embryos have been pointed to as evidence for evolution. We probably don't need this now, since it doesn't really add anything to the huge body of evidence, since we are so reductionist to gene and molecular level. However, shouldn't this be included for historical purposes at least? Even the evidence for common descent article barely mentions it.--Africangenesis08:15, 8 May 2007 (UTC)
Apropos, I think the article on embryology could benefit from some development. I am no expert and not competent to work on it, but perhaps some pf you active on this page can help improve that article. We spend a lot of (constructive) time improving this article - but sometimes important linked articles are neglected ... Slrubenstein | Talk12:01, 8 May 2007 (UTC)
The evidence for evolution section should be deleted. How many times do we need to remind people of this? The section was already renamed before following a discussion, but Orangemarlin apparently wasn't paying any attention to the ongoing discussions and, out of confusion, reverted a lot of in-progress changes during a lull. An "evidence" section is a completely inane idea, because everything in biology is, in one way or another, "evidence" for evolution. The reason the "evidence" section needs to be deleted is the same reason that Evidence of evolution was recently changed to Evidence of common descent: a discussion of "evidence" is integral to every aspect of evolution, so it should, properly, be discussed in the relevant section instead. For example, the evidence for mutation should be discussed under Evolution#Mutation; the evidence for speciation should be discussed under Evolution#Speciation and exinction; the evidence of common descent should be discussed under Evolution#Common descent; etc.! A single centralized section for "evidence" makes as little sense as having a single centralized section for "theories" or for "facts". That is why the "evidence" section was in the process of being shortened and reorganized into "Homology" and "Phylogeny" subsections of the new "Common descent" oversection (in this order: "Common descent" lead, "Homology" (encompassing both anatomical and molecular homologies), "History of life" (including a paragraph on abiogenesis), and "Phylogeny and systematics" (integrating information on the relationships between organisms, formerly discussed in a variety of other sections). The fact that this reorganization was reverted before it could be finished, while the editors who had been working on it were taking a break, is purely and simply an error—and a truly ridiculous one. -Silence23:49, 8 May 2007 (UTC)
By the way, if you consider this is a reversion, then I'm guilty. If I change the name of section, because it wasn't clear what it was representing, then that's hardly a reason for your attack above. Orangemarlin00:34, 9 May 2007 (UTC)
Orangemarlin is a valuable editor, and I'm sure he didn't mean to backpedal on this. In principle I agree with Silence's point, that "evidence" should be distributed within relevant sections... although for folks who truly need a quick-and-dirty education in Evolution, condensing all of it in one section can be helpful. I can see it going either way. Also, I have never been too fond of the word "evidence" in this context, because it sort of implies a kind of detective-guesswork thing, which science really isn't. Scientists also rarely use the phrase "evidence of evolution" and are more apt to use phrases like "evolutionary patterns in:" genomes, homology, phylogenetics, the fossil record, whatever. Anyway, both Silence and Orangemarlin have proven themselves to be valuable, objective, and non-POV editors, so it will be nice to see "everyone getting along" again soon (remember when you were all tapping your feet waiting for me to quit arguing with Gnixon?) Peace, TxMCJ07:31, 9 May 2007 (UTC)
This is slightly off topic, but I wanted to address this article. Considering Evolution is the foundation of Biology, the quality of Evolution far surpasses the article on Biology. Moreover, Biology should be the core article for everything else about biology in Wikipedia, yet it is poorly written, barely referenced, and makes a poor reference source for all of the better articles on Wiki. If any of you have time, please head on over and edit if you can. I know the Evolution/Creation articles are about 7 full time jobs, but Biology needs help. Orangemarlin16:03, 9 May 2007 (UTC)
Perhaps your comment is badly phrased OM? Evolution is fundamental for the current understanding of major parts of modern biology but without evolutionary theory parts of biology would still be valid and topics about microscopy or organismal vs cell theory could be validly discussed without an understanding of evolution (although with it some discussions would inevitably be enhanced).
However, this point aside I will look at the bio page and if it lacking then well spotted ....Candy16:16, 9 May 2007 (UTC)
Well, partially poorly worded, but really without Evolution, the Earth would be filled with a chemical soup, maybe with some one-celled bacteria, all of the same species, lying around. And Wikipedia wouldn't exist. George W. Bush would never have stolen the election in Florida. And the New York Yankees will never win a World Series EVER. I digress. My point is that yes, if Creationists are right (and then I have a lot of apologies to make), Biology would still be an important science. But without Evolution, nothing would exist biologically speaking. Or it would be quite dull (with just one species of Bacteria), but we wouldn't be around to care. That's about as philosophical I can get without an additional cup of coffee this morning. Orangemarlin16:38, 9 May 2007 (UTC)
For such an important article, I think we should put this through another round of peer-review before submission as a FAC. I'll try to get some input from experts in the field as well, scientists working in this area tend to recognise the importance of communicating with the public. TimVickers22:23, 9 May 2007 (UTC)
Table of Contents
I have moved the ToC to the left and up a bit, to allow the text to flow around it. It looks fine with my browser (Netscape 8.1 rendered with Foxfire), but may not in some. I realise this is controversial, but anything that eliminates the large blank space to the right of the ToC has to help. Anyone with more wiki-markup skill than me is welcome to try a better solution. Esseh05:30, 10 May 2007 (UTC)
I'm sorry I reverted that. It looks really bad on small screens and low resolutions. Personally, I don't think the white space is that bad, the TOC in books usually has lots of white space around it! TimVickers06:02, 10 May 2007 (UTC)
Tim, no problem. It was an experiment, and I was aware it might cause problems. Cheers, and good luck with the editing. As I said, no more tinkering on my part. Esseh07:30, 10 May 2007 (UTC)
Small mutations make big changes?
I hope this isn't too inappropriate of me to post on this talk page, but in this ars technica news post they talk about a small mutation in neuropsin of chimps created a longer splice variant found in humans, demonstrating how even small mutations can have large effects. Thought it might be of interest for editors of this article, as it's a interesting example. Delta Tango • Talk15:30, 11 May 2007 (UTC)
In the "Natural selection" section I've replaced the discussion of fitness in terms of traits with fitness in terms of phenotypes. A trait is too general a term to describe fitness with, the trait "fur colour" for example cannot be assessed for fitness. Instead, it is a phenotype such as "white fur colour" might have fitness implications. TimVickers21:25, 12 May 2007 (UTC)
Doing some more reading, I see the article in Wikipedia defines traits incorrectly. I have corrected my correction! TimVickers22:28, 12 May 2007 (UTC)
Lamarck
As an experiment, I have removed half of the Lamarck discussion from the History section. I'm wondering if in-depth discussion of this minor and incorrect theory just confuses the reader and adds little to the article. Do people think this reads more clearly in this version or the previous version? TimVickers02:03, 13 May 2007 (UTC)
History
It seemed rather disturbing to me that Lamarck popped up after 1859 rather than in 1809, so I've tried to reorganise and clarify that section. Some relevant minor points have been added: if references are needed these can be produced. .. dave souza, talk21:23, 27 April 2007 (UTC)
Quoting HF Osborn for the history of evolution is a Bad Idea. Osborn, a neo-Lamarckian, was attempting to deprecate the contributions of Darwin by finding precursors from anyone and any source that even remotely sounded like evolution was taken as being it. In fact, the first evolutionary view was that of Pierre Maupertuis in 1745's Venus Physique. Prior to that, species were thought either to be malleable but roughly stable, or, from 1684, fixed for reasons of piety (from John Ray on). There was no transformism of species because there was no real notion of the fixity of species before that time. John Wilkins00:42, 10 May 2007 (UTC)
I've substituted the first ref, but it seems a good source for the second as it gives what appear to be genuine examples of Lemarckian writing. Do you think this is OK, of could you suggest a better source? TimVickers01:00, 10 May 2007 (UTC)
My best accessible and reliable reference for this is perhaps Lois Magner's History of the life sciences, or perhaps Grene and Depew's Philosophy of biology: an episodic history. But I have further concerns. Anaximander is not an evolutionist (see my Darwin's precursor's FAQ at the talkorigins.org archive [3]). His view is basically an etiology: an account of things in terms of a mythical event. He did not think that humans evolved from fish - but that a human developed from a fish once. Likewise Empedocles. These are myths, not accounts of evolution.
Second, we have a problem with "Lamarckism". Darwin thought that what happened to adult organisms affected inheritance - to that extent he was a "Lamarckist". Darwin's student Romanes in fact made it a hallmark of "Darwinism" that one believed this and denigrated Wallace and Weismann for denying the master's view. Everybody believed this at the time; Darwin was different in that he did not require that particular structures or information were formed by external traits, only their heritability ("use and disuse"). The neo-Lamarckians of the period from 1880-1920 or so are not very like Lamarck. And Lamarck's linear view of evolution was the default transformism of European, particularly French speaking, thought right up until the 1920s. Peter Bowler's Evolution: The History of an Idea is a good source here, not Osborn, who in my opinion generated a whole slew of myths.
Finally, I would recommend not believing much of what Ernst Mayr says in The Growth of Biological Knowledge. Mayr is also a generator of myths (some of which I believed when I wrote that FAQ), and is to say the least idiosyncratic as a historian of biology. John Wilkins01:40, 10 May 2007 (UTC)
The following discussion has been closed. Please do not modify it.
The current titling and content present evolution as though it is a fact when IT IS ONLY A THEORY and there are other competing theories about the occurrence of natural and biological phenomena. I am deeply disturbed by this as a horrendous un-NPOV issue.203.49.223.15309:25, 13 May 2007 (UTC)
This has been discussed. Please see Talk:Evolution/FAQ#Why is evolution described as though it's a fact? Isn't evolution just a theory?. In science, a "theory" is a well-supported explanation for phenomena; examples of other theories include germ theory (the idea that many diseases are caused by microorganisms), plate tectonics theory, and gravitational theory. Theories can never become facts, because facts are observations, whereas theories are explanations for observations; therefore it is not a criticism to call something a theory, and makes as little sense as calling something "just a fact".
Currently, mainstream science recognizes no viable theories that are competing with modern synthetic theory; although it is fully possible that such a theory may arise in the future (and it is near-certain that the current theory will be revised in various ways over time, at least regarding minor details), it is against Wikipedia policy for us to jump the gun and try to guess at which ideas science will accept as right or wrong in the future. See Wikipedia:No original research and Wikipedia:Neutral_point_of_view#Undue_weight. Even if we agreed with you, it would be against policy for us to place our views higher than those of mainstream science. If you want changes made, then cite reputable peer-reviewed scientific sources denying evolutionary theory; otherwise, our hands are tied. -Silence09:47, 13 May 2007 (UTC)
Silence, you are a good person but really, there is no point in responding to people who haven't even read the article. They do not intend to make positive contributions to Wikiepdia, they are just using the wiki feature as a way to broadcast their own POV. The article itself addresses these issues, clearly, the anonymous user doesn't even care to read it. So why bother responding? Slrubenstein | Talk10:44, 13 May 2007 (UTC)
Sufficient, certainly. But not optimal. A brief, clear explanatory message (accompanied by links for further information) is optimal; being concise and to-the-point is beneficial, but being dismissive is not. Something to consider: we sometimes waste as much time telling each other not to respond to creationists as we do responding to them. The most ideal way to respond to creationist queries like this would be with a set of copy-pasted "form" responses, tailored to the situation and always short and providing helpful links.
Simply telling people to read the archives is unrealistic (even most of the article's current editors haven't read most of the archives), and most of this article's editors probably haven't read this entire article either, much less understood it all. Directing people to the FAQ or being specific in the information from the article that they missed is more helpful and practical.
From what I've seen, being a creationist doesn't make you an evil monster; it doesn't even, in itself, make you completely, 100% immune to contrary arguments or facts. Individuals who are clearly new to Wikipedia shouldn't be shouted at or insulted just for raising a good-faith (albeit misinformed) concern that happens to have been addressed before; by treating such issues respectfully—but, again, as concisely as possible, and preferably with only one user responding so that the editors can quickly move on back to the article—we make it more likely that the editors in question will either be persuaded, or at least gain a better understanding of the issue, and in turn be more likely to be an asset to Wikipedia in the future, rather than a nuisance. If you treat everyone who raises a resolved issue as a common pest, they will inevitably become common pests. Again, we obviously shouldn't waste much time on this, but spending a couple of sentences (something a little beyond just "read the archives, noob") is not necessarily a bad thing.
If the title issue is a reoccurring theme put forward by either creationist with an axe to grind or an editor with no understanding of the scientific use of the word "theory" then rather than RTFA how about an info box at the top of this talk page which redirects any query about the use of the word "theory" to the correct page on Wikipedia, and also says that there is no point starting a discussion about the name change as it will most likely not be considered. Darrenhusted12:55, 13 May 2007 (UTC)
First, there isn't room to have such a message for every common creationist claim. Second, most people already don't bother to read the top of the Talk page, because it's so long and complicated. Expanding it will just worsen that. Third, we already do that, in effect: that's what the link to Talk:Evolution/FAQ is for. What I'm noting is the best way to respond to creationist claims once they've actually been made, not to prevent them.
My recommendation is to have a pleasant, non-dismissive, but very concise "form response" which can be copy-pasted either for specific common creationist claims (e.g., "just a theory"), or for any issue already addressed in the archives/FAQ. No matter what we do, there will always be creationists reposting these arguments here. What matters isn't how many we get, which we largely can't control, but how we respond to them in order to (1) minimize the time and effort expended by editors here, (2) avoid unnecessarily offending the creationist, in order to avoid escalation into an argument (thus tying in to 1), and (3) give the creationist an opportunity to become a productive member of Wikipedia, by showing that people can disagree and still be calm and reasonable, and work together to make the encyclopedia better. Being non-dismissive, level-headed, and concise in our responses also has the advantage of being the best way to correct misconceptions about evolution (since it makes people more likely to be receptive to contrary ideas), and thus slightly furthers a goal of many of the editors here: countering misinformation about evolution. -Silence16:28, 13 May 2007 (UTC)
I agree with Silence. First of all, maybe they don't know better, and a non-dismissive and concise discussion about the point is appropriate, and who knows, maybe they come to understand that Evolution stands on good scientific grounds. I know, 99.9% of the time, that's probably not true. I'm glad Silence is patience with this type of posting, because I stand with almost everyone else that these Creationists need to go far away, maybe to Conservapedia or something. I enjoy FeloniousMonk's usual response, but Silence is probably doing the right thing. Orangemarlin03:56, 14 May 2007 (UTC)
(unindent) Maybe most creationists won't accept that evolutionary theory "stands on good scientific grounds", but if we can at least demonstrate that editors here are not closed-minded anti-religious extremists, but reasonable and intelligent fellow human beings, that will eliminate most potential creationist conflicts right off the bat.
The point of explaining these things isn't just to convince them that evolution is valid science; even for the more open-minded creationists, that's more likely to take months than minutes. It's more to hammer home Wikipedia policy (which renders the personal views of its editors irrelevant), to address ambiguities and misconceptions about evolution which would get in the way of working on the article (and which remind us of things that the article should probably address, if the ambiguity or misconception is common enough!), and to firmly establish that modern evolutionary theory is overwhelmingly supported by scientific consensus, regardless of whether those scientists are wrong.
Really, that's all we need. You don't need even the slightest grasp on population genetics or molecular biology or anything of the sort to understand the simple fact that evolutionary theory is accepted as valid by the scientific community, that no competing ideas are, and that Wikipedia policy requires us to base articles on current scientific consensus. As long as you accept these three facts, you can personally think that evolution is complete bullshit (though, admittedly, this would require a very weak grasp on scientific fact and method), but still be a valuable contributor to the article.
And even if that principle (that you don't need to support or accept X in order to improve its article) is often difficult to apply in practice for Evolution, it's still healthy and productive for us to encourage it, if only to keep the Talk page atmosphere calm, reasonable, and level-headed—even in the face of the most outrageous or absurd claims. When you respond to absurdity with impatience and attacks (e.g., replying to "Evolution is just a theory!" with "Oh great, another stupid creationist troll" instead of "In science, theories are well-supported explanations, not speculative ideas"), you not only make the arguer more enraged and determined, but you also strengthen his argument in the eyes of uninformed observers. Keep that in mind. -Silence20:21, 14 May 2007 (UTC)
I agree, and I like your idea of having a "form response", although we already have that in a sense with the FAQ. garik20:28, 14 May 2007 (UTC)
As has been noted, the FAQ has the disadvantage of being on a separate page (if creationists don't even bother to read the article, why would they bother to read the top of the Talk page?) and of being a bit long (though it starts with a good summary and I don't think it's any longer than necessary). Although it should be our main method for correcting common misconceptions, having a brief form to copy-paste onto this Talk page directing creationists to the FAQ (and perhaps summarizing one of the FAQ's points) could only do good. -Silence00:08, 15 May 2007 (UTC)
However, please note that the anonymous editor who started this section is nowhere to be seen. That's why I lack patience, but then again I try not to answer these editors comments. Orangemarlin00:23, 15 May 2007 (UTC)
The quote should clearly be removed. It is, first, irrelevant in its article context: whether Darwin believed in God has nothing to do with whether abiogenesis is a part of evolutionary biology. It is, second, misleading in its implication: Darwin, by his own admission, became an agnostic later in life, so his faith in God at the very least fluctuated. And it is, third, POVed and offensive in its presentation: it seemingly gives Darwin's theism as an example of how "understanding that evolution has occurred and investigating how this came about does not require an understanding of the origin of life"—in other words, it's saying that theism is a misunderstanding of the origin of life! Whether this is true or not, it is not Wikipedia's place to assert this (though I suspect that it is being asserted here only out of error, as this line was hastily interjected without full consideration for its context).
I don't even see why we have an "origin of life" section in "evolutionary history" at all, since abiogenesis is, if anything, evolutionary prehistory. It certainly conflates the important distinction between chemical and biological evolution, thus undermining the entire rest of the article's clarity and focus. For that matter, I don't see why we have a section called "Major events in evolutionary history": it's awkward and possibly misleading. -Silence21:35, 14 May 2007 (UTC)
(Oh, and the reason it's possibly misleading is because "events" can imply sudden, singular occurrences, when in fact evolutionary history is all about gradual adjustments and statistical trends; and because "history" can imply written history, as in "dinosaurs lived before history"/"dinosaurs are prehistoric". Just to be explicit.) -Silence21:40, 14 May 2007 (UTC)
I have mixed feelings about including that Darwin quote. Scientifically it has no place in the article, but it might be useful as a sort of lollipop for reasonably intelligent Christians who are trying to reconcile Evolution with their faith. The main point to make (and I think this is what Silence is saying) is that Evolution is not about first origins, it is about everything that happened since then. TxMCJ21:55, 14 May 2007 (UTC)
I'm not wedded to the quote, cut it if you want. However, we need a section on abiogenesis since this is so commonly treated as part of evolution we have to address the fact that it isn't. Moreover, as the section explains, it is difficult to draw a clear line between chemical and biological evolution since biological entities are simply complex self-reproducing assemblies of chemicals. Defining life is not an easy task! The section on major events in evolutionary history is vital, but it does need to be more clearly written. The article would not be a comprehensive discussion of the changes in organisms over time if we did not at least outline what changes have taken place over time. TimVickers21:57, 14 May 2007 (UTC)
We can address the issue that abiogenesis isn't evolution without giving that misconception an entire section—and we did exactly that in past versions of the article, where "history of life" was a section encompassing both abiogenesis and evolution. The problem with having a section on abiogenesis is that it has directly the opposite effect of what we intend: it will imply to any casual reader that abiogenesis is a part of evolution! After all, if it wasn't, why would we have a section on it in Evolution? See the problem? It would be like having a section on Barack Obama titled "Muslim extremism" in order to address the misconception that Obama is a muslim: in the process of giving such pre-eminence to a mistake (without explicitly specifying that it's a mistake with some overly verbose title like "Misconception that abiogenesis is part of evolutionary theory or involves the same processes as biological evolution"), we validate it, at least for most casual readers.
Yes, it is difficult to draw a clear line between the biological and the non-biological sometimes, because it is difficult to define what does and doesn't constitute "life" (though I don't think I'd go so far as to say that it's difficult to draw a line between biological and chemical evolution, since "evolution" usually has very different specialized meanings in each context). But that doesn't excuse worsening the ambiguity by including clearly non-biological process (like early-stage abiogenesis) under the category of "biological evolution". If we don't draw the line at all, then it's arbitrary even to stop at abiogenesis, and we should also discuss the synthesis of elements, the development of stars and galaxies, and the Big Bang itself. If we do draw the line, we ought to follow scientific consensus and draw it between abiogenesis and the earliest life; we don't need to specify the exact form the earliest life took in order to establish that much. Hell, even the very first organism didn't "evolve", under the stricter biological definition, because evolution is change on a population (and generational), not individual, level.
I also agree that the basic information in the "events" section is vital (though I disagree with its current form). If I didn't agree, I probably wouldn't have written that entire section. :) It just needs some improvement. -Silence22:28, 14 May 2007 (UTC)
Quote should go. No one's religious perspective is critical to the discussion of Evolution. In fact, the only place I'd use that quote is the article about Charles Darwin. As for abiogenesis, a billion years ago (OK, I mean figuratively) when I took an evolution class in college, the professor stated that Evolution does not cover the beginning of life, just the nanosecond after it appeared. Maybe he was just avoiding a lecture on the topic or he had a valid point. But I thought around here we kept abiogenesis over in another article. To me abiogenesis is organic chemistry, but I'm no expert. Orangemarlin22:24, 14 May 2007 (UTC)
Can we please refrain from using linear, progressive series of images
Ape skeleton discussion
The following discussion has been closed. Please do not modify it.
I've posted on this topic before. I realize that the top image on the evolution page is not really a linear-progression series of images (like the famous ape-becomes hunchbacked australopithecine-becomes neanderthal-becomes Homo habilis with a club and loincloth-becomes modern man)... but it sure gives a first impression of that kind of image, which is hugely rampant in popular culture. I realize that this particular image merely shows a series of skeletons, but it's a valid question: why are humans placed on the far right, with other Homininae to the immediate left? Because of the long tradition of such linear/progressive series, which are extremely outdated now and in fact scientifically incorrect (these are cousins, not intermediates). Again, I realize the current picture does not *really* fall into this category, but it is damn close (humans on the right, adjacent to gorilla and chimp, etc.) If you reversed gorilla and chimp and drew a phylogeny underneath it, it would be OK, but regardless: I can think of an infinite number of preferable images for the first picture on the page... a phylogeny, Archaeopteryx, a geological time scale with fossils embedded, hell, even a picture of a coelacanth. Please consider replacing the image with something more consistent with modern evolutionary thought TxMCJ22:04, 14 May 2007 (UTC)
Is the new version better? Other images would be fine, this is just one that is immediately visually striking and prompts anybody to consider evolution, just by looking at it. TimVickers22:25, 14 May 2007 (UTC)
It is better for "those in the know", but seriously: the "chain of human progress" cartoon is so iconic in popular culture, art, and media, that the brain instantly connects this image with the other... the hunched backs and the right-facing bodies contribute to this. If you want to use the hominid skeletons, arrange them in a circle or something and do a flip-horizonal on half of them. A lot of work, and maybe unnecessary. Evolution is not only about primates and humans, so it might be nice to de-emphasize that a bit with our first image. Why don't we use another great iconic image that is a lot more interesting and informative: one that shows homology of forelimb bones between bats, whales, birds, carnivores, and primates? TxMCJ22:35, 14 May 2007 (UTC)
If you can find a nice GFDL example, that would be great. Myself, I think it's a nice family portrait! TimVickers22:37, 14 May 2007 (UTC)
That's a good suggestion TxMCJ, I've flipped the right-most skeletons. I don't think anybody could look at the current image and extract any kind of progression. Thanks for all the helpful comments. TimVickers23:15, 14 May 2007 (UTC)
Well, it isn't. It's highly misleading and confusing to anyone who doesn't already know about the basics of evolution (i.e., to 100% of our primary target audience!). Even the caption is inaccurate! It erroneously claims that included species are all members of the family Hominidae (the great apes); in reality, gibbons are not great apes. In fact, "gibbon" is synonymous with "lesser ape". This is a family portrait of the hominoids (superfamily Hominoidea), not of the hominids (family Hominidae). -Silence22:43, 14 May 2007 (UTC)
It can imply a variety of things. First, it can imply that the great apes are any more significant than other species in evolution; although the image might suit human evolution, it's importance here serves only to reinforce anthropocentric prejudices and misunderstandings. Second, it can imply that evolution is only macroevolutionary: we are comparing different species, but really, you could also compare different individual humans (or individual orangutans, etc.) and point to them as examples of evolution. Most of evolutionary biology is concerned with microevolution, but most people don't even realize that microevolution is evolution; we reinforce that misconception by only comparing different species in our article-leading image. It also implies, by showing the five skeletons in a row, that evolution is somehow progressing from the gibbons to the orangutans to the humans to the gorillas to the chimpanzees. As noted, this effect is emphasized by the fact that the image bears a strong resemblance to the misleading old "ape to man" image. -Silence23:04, 14 May 2007 (UTC)
Silence is absolutely correct on all of the above. The additional issues (below) are also true, but perhaps of secondary importance. The main modern objection to linear-progression type images (which this one very closely resembles and undoubtedly stems from the tradition of such progressions) is: as Silence noted, extant species do not evolve into extant species... and even if you show transitional forms, it is also biased to imply that evolution has been "leading up to" some end result. This is the same objection scientists have with some of the classic images of the evolution of the modern horse through Eohippus and similar cousins. TxMCJ 00:30, 15 May 2007 (UTC) TxMCJ00:25, 15 May 2007 (UTC)
It's also a biased image: it includes four great apes, and only 1 lesser ape, even though there are many more gibbons than great apes. There are 13 gibbon species, but only 7 great ape species (2 orangutans, 2 gorillas, 2 chimpanzees, 1 human). This also raises the question: what type species are being used for each example? This is particularly problematic for the gibbon, since there are over a dozen diverse species it could be!
Also, yet another highly misleading inaccuracy: the model is not (as one would assume) to scale! The gibbon is shown at twice its natural size, yet this important fact is left completely unstated in the description. (And the other skeletons may be inaccurate, too; I don't know.) -Silence22:57, 14 May 2007 (UTC)
So you added the NPOV tag due to a bias against Gibbons? I've shrunk the gibbon skeleton to natural size, this should deal with your second point. I think all these points are not really inherent in the image, instead they are cultural baggage that some people bring to the article. Could we focus on giving constructive suggestions of new images - with links please - rather than complaining about possible implications of the present image? Thanks. TimVickers23:06, 14 May 2007 (UTC)
The bias problem is a serious one. It's the exact same problem we'd have if the top image of the Life article was of a human, or if the top image of Mammal or Vertebrate was. Why humans? If we're going to pick a random species (or group of species, e.g., the great apes), we should pick one that is as typical as possible. That's why we wouldn't want to include a platypus at the top of any of those articles either.
Hear, here! I vote for pictures of a bacterium, a flower, and an arthropod. Just kidding (but those would be much more representative of "Life") TxMCJ00:25, 15 May 2007 (UTC)
My constructive suggestion for a new image: no image!! The image at the top of the "evolution" template more than suffices. Adding an image has been solely to the detriment of the article, not only because of the problems with the image itself, but also because including any image makes that part of the article needlessly crowded and off-balance, pushing aside the first section of the article, etc. Your improvements to the image are good ones, and might justify keeping the article around in the "Homology" section; but they don't make it a good idea to put it at the top of the article. Why deal with any "baggage" (even if it's a problem with the readers) when we don't have to? -Silence23:37, 14 May 2007 (UTC)
I've moved the template up, which deals with the layout problem with the first section. I think if we do not put a lead image we lose the opportunity to grab the readers attention with a striking and informative illustration. If you have a GFDL image of an alternative family group, that would be great, perhaps even platypuses or platypi? TimVickers23:51, 14 May 2007 (UTC)
The article looks just as bad now, if not worse; instead of the first section being squeezed, now the third paragraph is squeezed, making the lead look horribly disjointed and crowded. If you want to include a better image at the top, why not just try to find a smaller one to put in the "evolution" template itself? Something that "grabs" people more than the phylogenetic tree, but is at least as informative and useful? That would solve both problems. (By the way, "platypuses" is correct, but "platypi" is pseudolatin.) -Silence23:57, 14 May 2007 (UTC)
I see my sense of humor is lost on you. It must be the language barrier. Please add your suggestions to the section below. TimVickers00:06, 15 May 2007 (UTC)
Oh, I caught the "platypus" joke. That's why I didn't respond to it, just corrected the grammar. :) I only have a limited time to respond to a lot of comments, so I stuck to the essential parts. (Yes, in my view, obscure pluralization rules are "essential"! >:)) -Silence01:59, 15 May 2007 (UTC)
I agree 100% with Silence and TxMCJ - we should avoid anything that may lead people to think evolution is linear and progressive. It is amazing how many people think humans (or any species) is "more evolved" than others, or we (or some other species" is at the "top" of the food chain. If anything this article should educate people as to they this is not the case. Slrubenstein | Talk13:05, 15 May 2007 (UTC)
Oh, for crying out loud
More discussion of images
The following discussion has been closed. Please do not modify it.
How long has the "the neutrality of this article is disputed" been on the page, and how did that happen? What a royal pain in the neck. Does Wikipedia policy allow for that to be posted on scientific articles that generate social controversy? This article WILL NEVER EVER EVER contain "an alternative POV" because a scientific alternative to Evolution does not exist -- therefore to many cretins, this article will always appear non-neutral and they will always be able to whine about it. Can we remove that under the pretext that science is not neutral or non-neutral, it only reaches consensus based on strong theory and data? Crikey... TxMCJ22:24, 14 May 2007 (UTC)
I have removed the tag and the Darwin quote that prompted Silence to add it, since none of us seemed to think it added anything very useful. I don't think Silence was "whining" about anything, but hopefully that's the problem solved. TimVickers22:28, 14 May 2007 (UTC)
Don't assume that the quote was the only reason I added the tags. I added them for several reasons, the most immediate being the precise issue TxMCJ just brought up: the image at the top of the article is awful. First, it is misleading in that it implies that evolution is linear. Second, it is anthropocentric for focusing only on humans and their nearest relatives (although at least it isn't one of those absurd images with humans at the end of the "chain of progress" from "lesser" apes). And third, it is not actually an example of evolution (as, for example, a model of a population's alleles varying over successive generations would be), but of homology, a specific (albeit important) type of evidence of evolution. What's next, are we going to include a photo of the Cosmic Microwave Background Radiation at the top of Big Bang? A microscope at the top of bacteria?
HAHAHA, you crack me up Silence -- I love it! (That's a good thing, by the way). "A microscope at the top of bacteria"... classic... TxMCJ00:27, 15 May 2007 (UTC)
And TxMCJ, don't assume that just because there's a tag on Evolution that that means a creationist put it there. Sometimes, even controversial articles have NPOV problems, ambiguities, and other shortcomings. In fact, surprisingly, they have such problems more often than non-controversial ones. :) -Silence22:37, 14 May 2007 (UTC)
Yeah, but we're trying to get this article right Silence. Couldn't you just drop a note here, and we figure out how to do it best. No one, I mean no one that is a regular editor of this article is going to stand in the way of getting it right. No one put much thought into the image, so we can eliminate it or get a better one. The controversial articles need tags, because people can stand on some principle. No one here will, unless a couple of very POV editors show up. Orangemarlin22:40, 14 May 2007 (UTC)
I was in the process of writing exactly that note, but got into an edit conflict because of the sudden flurry of activity here. It's difficult to respond to many different posts simultaneously when other editors are doing the same thing at the same time, and the problem (the misleading image at the top of this very prominent article) was urgent. -Silence22:46, 14 May 2007 (UTC)
I did not assume anything, Silence, that is why I put the message on your talk page. The first problem has now been dealt with, see new version of image. I think a touch of anthropocentricity can be forgiven in one of the images of an article aimed (mainly?) at a human readership! The image is however an example of an outcome of evolution, which is one of the major topics of the article. We should not focus on mechanism to the exclusion of all else. Since an image can't cover all of the topics in this article we have to choose one. This was one aspect I thought important, but that is only my opinion. Other suggestions for good lead images are welcome. Please. Just post them here and let's consider them. TimVickers22:44, 14 May 2007 (UTC)
I agree entirely: a touch of anthropocentricity is quite acceptable if it helps present the information clearly to readers. As you say, it is acceptable in one of the images. However, it is not acceptable for the top image. The difference is the same as if you included human at the top of Life, vs. including it near the middle or something: the latter is only very slight bias, and forgivable, whereas the former is more noticeable and problematic. The same applies here, since evolution occurs equally for all life forms. -Silence23:44, 14 May 2007 (UTC)
By the way, the image is an example of an outcome of evolution, but it's a useless one for any readers who don't already understand evolution! That is why it doesn't belong at the top. The purpose of images is to help explain important things to the reader; an ideal image at the top of the article would help readers understand what evolution is, not what it results in. To deal with the results before the process itself is completely backwards; including an image of the apes at the top of the evolution article is like including an image of Earth at the top of the stellar evolution or gravity or Big Bang articles: it is not helpful. We should provide images of the outcomes of evolution after the article has successfully explained what evolution is. -Silence23:52, 14 May 2007 (UTC)
I almost hate to say it, but Silence is correct. The main problem with the former lead image (in my mind) is that it gives the impression of "directed evolution". Ultimately, all extant life forms are the "epitome" of evolution (to date) in their lineages. We must avoid not just the anthropocentric, but the static view that evolution is "over", and this is the result. Undoubtedly, Homo sapiens will look much different in a couple of millenia (if the species exists). As for suggestions.... see below. Esseh00:40, 15 May 2007 (UTC)
Oppose any lead image for this article. There's no room for one outside of the already-large "evolution" series box. Barraging readers with too many pictures before they can ground themselves is just as bad as having no images at all, if not worse. Most articles as broad as this one don't have lead images outside of a series box: see, e.g., cheese, history of Arizona, campaign history of the Roman military, history of Poland (1945–1989) (all featured articles). -Silence00:05, 15 May 2007 (UTC)
ehhrm... I don't like the generic images like that. The best picture would be of a phylogeny of some sort. Hands Down.
Another option might be a map image showing the global biogeographic regions, with representative organisms drawn in. But a phylogeny (any phylogeny) gets my first vote. If nothing in biology makes sense except in light of evolution [T. Dobzhansky], then nothing in evolution makes sense except in light of phylogeny [J. Felsenstein and/or the SSB]TxMCJ00:36, 15 May 2007 (UTC)
OK, this is going to sound lame, but I don't know how to post images to Wikipedia, nor do I know how to check for fair/non-fair use, or whatever. But the type of image I'm talking about is a map with the biogeographic boundaries drawn in, and with some pictures of organisms on the different zones. Unfortunately, such images tend to be vertebrate animal-specific. In particular, an image such as Wallace's Line showing the different flora and fauna on both sides might be good here... but again, my main vote is for a phylogeny. Or even of Archaeopteryx, which is an excellent metaphor of many things (adaptation, transition, key innovation, extinction, deep time...)TxMCJ00:42, 15 May 2007 (UTC)
You're not lame!!!! I gave up long ago trying to post images, because it is just too complicated. And everytime I pull an image I figure is legal, it gets deleted, and I get a fair use nastygram from an administrator. LOL. So I just surrendered. It's too hard to do. Orangemarlin00:44, 15 May 2007 (UTC)
Wow, I've never really felt special before but I did manage to work out how to upload images ;) If you have such an image you can either e-mail it to me (using the link on my user page) or click on "Upload file" in the toolbox on the left and follow the instructions. Unfortunately this is another human one and rather "progressive", but its a good illustration. TimVickers00:46, 15 May 2007 (UTC)
A phylogeny is not a bad idea, but also suffers from the "final outcome" syndrome for an ongoing process.
I have to disagree here... the tips of a phylogeny are NOT a "final outcome", they are snapshots in evolutionary time. This would be clear if an axis of time was given alongside the phylogeny. TxMCJ02:42, 15 May 2007 (UTC)
Same probelm with the skulls (that confliced me out of this). As an alternative suggestion, what about a diagrammatic example of evolution in action. Just about the only example I can think of where the actions of selective pressure have resulted in novel allele distributions is in the so-called bacterial "super bugs" appearing in hopsitals as a result of the selective pressure of antibiotics. It would also bring home the dangers of ignoring the lessons of natural selection and evolutionary principles. It's also currently in the media's attention, and accessible to most people, though unlikely to be connected with evolutionary principles in either the media or most peoples' minds. Anyone game for making such a diagram? Thoughts? Silence, in particular I'd like to hear your views on this. Esseh00:52, 15 May 2007 (UTC)
Tim, not bad! I'd show more, and smaller dots, with fewer with high resistance, and a couple of intermediate steps, showing a more gradual decrease, or maybe which were killed, but that's the idea. Colourful and direct. Let's see if othere like it. Esseh01:04, 15 May 2007 (UTC)
A generic image is useless, and the skull image has the same problems as the skeleton one, and then some. If we're going to add an image to the top of the article, then I definitely think we should use one like what Esseh proposed: something that illustrates clearly how evolution actually occurs. The only problem I see with the image is the ambiguity of "Resistance level", and the fact that the "stages" nature of the image is difficult to parse on first glance. The latter is mainly because the "Resistance level" is placed right below "Final population", implying that it is a fourth "stage". It should be changed into a horizontal or otherwise differentiated more clearly. In fact, maybe it should just be removed altogether; I'm sure we could provide an adequate caption to explain the image.
I'm still not sure that we actually need this image at the top of the article, though. Although it's a very appealing image, it might be better-placed at the top of "mechanisms of evolution", especially if we can't find a visually appealing, uncluttered way to combine the evolution series box with the new image. We should consider both options. But I definitely support adding something like this somewhere on the page; it's simple, useful, and pretty. That's three for three. -Silence01:27, 15 May 2007 (UTC)
I can see why you'd want to add intermediary steps to the diagram, but the problem I see with that is that it would make the image too cluttered, and would make it much larger, which in turn would force us to shrink the image and thus make it far too hard on our readers to see the different dot colors and to read the text. However, here's an excellent solution to that issue: how about if we make an animation? (A simple one that wouldn't take up too much memory like the DNA one did.) Then we could present 5 or more stages of evolution in the space it takes to present only one! That would also give us more room to explain the image (with a caption and/or key) and to add dots!
Though I'm not sure yet that we should add many dots, or any at all; remember that the point is to keep things simple and having only a few large, colorful circles is the ideal in that respect. One change I would like, however, might be to alter the colors a little: perhaps have a less dramatic distribution, where there are, for example, 8 balls in the "before selection" stage, including 1 light-yellow, 1 yellow, 2 yellow-orange, 2 orange, 1 red-orange, and 1 red; the red-orange and the red survive to the "after selection"; and the "final population" (which we may want to rename, since no population is ever truly "final") has 1 yellow-orange, 1 orange, 2 red-orange, 2 red, 1 maroon, and 1 dark-maroon. Then again, that's probably overcomplicating things unnecessarily, and the issue I was trying to resolve (that the "final" population seemed too un-diverse in color compared to the "before") is perhaps a non-issue, since we would expect a recently-culled population to lack much diversity at first (population bottleneck). I'm sure there are good ways to represent all these things in a comprehensible way in an animation, whereas a non-animated presentation will necessarily be much more limited. -Silence01:44, 15 May 2007 (UTC)
Selection of resistant strains by antibioticsOK, I.m no artist, but this is the kind of image I was thinking of. The caption could be (and should be) changed, but I think the idea of gradual changes is illustrated, as is the idea of reproduction (each cell replicates once per frame). Just an idea. Esseh03:13, 15 May 2007 (UTC)
Aesthetics, size concerns, and labeling aside, the problems I see with this version are (1) the way the pinks die doesn't make sense, and seems overcomplicated; (2) because there are pinks rather than oranges, the initial population doesn't seem like a cohesive spectrum; (3) the dropoff of yellows seems far to extreme, as I doubt the yellow-determining allele would reach fixation in just one generation when it was clearly so widespread before; and (4) the starter population's homogeneity makes it non-obvious why there should randomly be pinks and reds amidst the yellows; why not some greens and light-greens, or better yet, make the dominant variant orange and have an equal starting number of yellows and reds? I also don't like that this version relies too much on lots of doses; not only does it seem very overcomplicated (we really shouldn't need more than about 2 doses to get the point across, if we're being efficient), but it also lacks one good feature of the original: distinct "between" stages where the survivors are shown alone.
Again, it seems to me that the best of both worlds could easily be accomplished if we went with an animation: we could use the "X"s or something like that in one frame to represent which individuals fail to reproduce, then in the next frame show only the remaining individuals (the ones selected for), and then in the frame after that show the next generation. That's 3-4 frames (depending on whether we want the "Xs" or anything) for one generation; repeat that once or twice more and I think the readers will get it just fine. Perhaps we could have three stages, the first and last being like the original diagram, but with an extra stage thrown in to show the transition more clearly. Maybe something like:
Before first selection: 1 light-yellow, 1 yellow, 2 yellow-orange, 2 orange, 1 red-orange, 1 red
After first selection: 1 red-orange, 1 red
Before second selection: 1 yellow-orange, 2 orange, 2 red-orange, 2 red, 1 dark-red
After second selection: 2 red-orange, 2 red, 1 dark-red
Final population: 3 red-orange, 3 red, 2 dark-red
I think that's simpler than the above version. Perhaps it's still overcomplicating things a little, though, with the number of colors and individuals... -Silence03:48, 15 May 2007 (UTC)
Although I don't think the image at the top with the waterfall quite does it, I do think IF we are going to lead with any image it should be something that illustrates the last paragraph of The evolution of Species - the point is that ecosystems evolve, speacies evolve relative to their place in an ecosystem, and DEFINITELY not that evolution has a direction, is progressive, or linear. Slrubenstein | Talk13:08, 15 May 2007 (UTC)
simplification or a stripping of explanatory readability?
Homeostasis discussion
The following discussion has been closed. Please do not modify it.
Tom, I know you are well intentioned, but it is impossible to follow what you are doing, your massive rearrangements make differencing of versions without going through your changes one by one difficult. You should make rearrangements rarely, with clear identification, and with assurances that no deletions or additions were performed at the same time. I also get a sense that, while adding references you are also stripping the article of coherance, as you apparently limit text to the narrowness of the particular citation, and the article is becoming a terse one to one sentence to citation correspondence. I know that I wanted homeostasis in the article and you have stripped it twice. The current status of the sentence is "Another possible advantage of gene duplication is that overlapping or redundant function in families of genes can allow retention of alleles that would otherwise have deleterious effects, thus increasing genetic diversity" At one time, the in addition to mention of the role of homeostasis, there was the focus on how the gene can persist, until it might become advantageous. Now the only result is genetic diversity, which as far as the article is concerned is some kind of dead end. From the article the only benefit one might infer of genetic diversity is avoiding the problems of inbreeding. I assume if one goes to the inbreeding article, one will find all sorts reasons to avoid it, that will apply to genetic diversity even in non-inbreeding circumstances. I don't know if the article once had more on the role and benefits of genetic diversity, but it certainly doesn't now. My concern is that you might be doing to the rest of the article, what I have noticed in the small part I've been following, that you may be making the article worse. I'd rather have a good article than featured article status, if the latter means the article must be assembled from a recombination of memes, with one meme per cite.
I think the community is assuming you are acting in good faith, and waiting for the dust to settle, to read the article. I just hope they can still remember some of the good things they might have lost (with the best of intentions), so that they can be restored to what may now be a better referenced and organized framework. I'd like the article to have coherance and explanatory value, so that the understanding of the reader is increased, and so that their motivation to follow the wikilinks is because their interest is aroused, and not because they have become confused by a terse disconnected sentence. With your flurry of activity what is the point of even looking at the article now, because its current state won't last very long.--Africangenesis03:58, 12 May 2007 (UTC)
Hi Africangenesis, yes I can assure you that I am acting in good faith and am indeed working hard to get this article as accurate, clear and fully-referenced as possible. If you have any serious concerns about my motives, I'd suggest you bring this up at the Administrator noticeboard, so you can get a second opinion. The problem with the previous additions in this section was that homeostasis is not the focus of the surrounding text on gene and genome duplication. Addition of this un-introduced concept with no definition and just a link in the middle of a sentence dealing with gene duplication is very confusing for the reader. I would suggest either giving redundancy a separate paragraph, with homeostasis explained as a parallel example to gene duplication, or simply dealing with it in a separate sentence. However, this does depend on us being able to find reliable sources to support this statement. What source were you using for this addition? this looks applicable, but I can't access full-text at home. TimVickers13:42, 12 May 2007 (UTC)
Nah, that's from 2005, homeostasis isn't news. I'll check my medical or biochemistry references. I don't doubt your good faith, just the quality of what you're doing to the article.--Africangenesis15:51, 12 May 2007 (UTC)
Here we go, "Biology" by Helena Curtis, copyright 1968, second edition pg 28 "Living things are homeostatic. Homeostatic simply means "staying the same". Perhaps the most familiar example of homeostasis is the remarkably constant body temperature we and other mammals are able to maintain despite temperature changes in the outside environment. Although not all living things maintain a constant temperature, all are homeostatic in their chemical composition." Later on, the Chapter 36, the title is "Homeostasis I: Excretion and Water Balance", has subsections such as "Ions and Osmotic Pressure", and "Acid-Base Balance". The Homeostasis II chapter was on temperature. Curtis also notes that better homeostasis, was probably one of the evolutonary advantages of multicellurity and larger body size. Stress response systems, and immune systems can also be considered homeostatic mechanisms. These mechanisms for maintaining internal state operate in a gene expression mileau. Imagine a gene mutation that makes a gene function less well, or nonfunctional. Perhaps it has a different effect now on acidity, or perhaps it destabilizes the genome. Homeostatic mechanisms step in the make these survivable, or of course, perhaps they don't, but the point its that mutations are more survivable, and genetic diversity greater than they might otherwise be.--Africangenesis16:32, 12 May 2007 (UTC)
I don't mean to interject, but Biology by Helena Curtis is still being used? I believe that was my Biology text 30 effing years ago!!!!! Orangemarlin03:58, 14 May 2007 (UTC)
It was still going strong in the 80s, but I see no signs that it is currently being used. My father-in-law was a biology professor, so I have benefitted from his hand-me-downs.--Africangenesis17:13, 16 May 2007 (UTC)
Physiologic or cellular homeostasis are not envolved in evolutionary processes (although they have evolved). The problem I see with the article is that mutations (of which duplications, indels and point mutations are the most abundant in genomes sequenced to date)is presented as the driving force behind evolution. That is mutationism and not neoDarwinism as hardened through the Modern synthesis. Natural selection is the driving force behind evolution and mutations are fodder for natural selection to act on populations (population genetics), in fact phenotypic or ecological speciation can occur before reproductive isolation or genetic isolation. Epigenetic changes can dramatical influence allele expression such as imprinting were you essentially have one allele. Mutations such as the transposon that produces insecticide resistance in fruit flies can be 80-90,000 years old and only till natural selection the last 100 years has it produced evolution. Population genetics and modeling is the crux of modern evolutionary biology. I find even the mention of traits and genes is misleading. Where there are examples of a single gene and a single trait, I think the phenotype should be emphasized. Often the genetic change is not directly correlated with a trait but a phenotype (nor do you have to have a genetic change but an epigenetic change). Like in dogs- size correlates with IGF like molecules, Darwin's finches beaks correlate with calmodulin, lateral plates and jaw structure in sticklebacks with ectodysplasin, etc. The calmodulin and IGF examples influences a whole host of signalling molecules and developmental events that produces a phenotype. Even identical cloned bacteria produce phenotypes, so genetic mutation is not neccessary for variation. The article presents natural selection and genetic drift on almost equal footing, which is not neoDarwinism. This must be an attempt at NPOV so I would recommend the literature I have mentioned before by Jablonka, Price, West-eberhard, etc should also be mentioned as well as the literature on epigenetics I have brought up repeatedly in the past. Just a passing comment. The article has improved and perhaps the last of my comments are just an anal penchant of my own perspective. GetAgrippa16:41, 12 May 2007 (UTC)
Homeostatic processes are intimately involved, even in the examples you gave. Not every adjustment it took to make a larger dog work, was under the control of IGF signalling. The mutation that increased IGF might have been fatal, if the temperature control system hadn't been able adjust to the new surface to volume ratio. The bone may have been thicker or denser to handle the increased weight more due to the homestatic response of the bone to stress than due to IGF, etc.--Africangenesis17:07, 12 May 2007 (UTC)
Natural selection is the driving force behind adaptation, but evolution in general is driven by a combination of forces. This is discussed in the fourth paragraph of the "Natural selection" section and based on references 81-84. Thanks for pointing this out, this point really should be made clearer, but it is wrong to equate adaptation and evolution - one is a sub-set of the other. I've re-worded this paragraph to try to cover this point. TimVickers17:08, 12 May 2007 (UTC)
I agree with your comments. My emphasis was mainly on a historical perspective and what to emphasize. Mutations or epimutations don't generate evolution-natural selection, genetic drift, and HGT and hyridization produce shifts in gene allele (or epiallele) frequencies in a population. I think laypersons should realize that variation is not neccessarily the results of mutations but may be the result of stochastic and environmental interactions on gene expression or from recombination during reproduction. I think many will assume that mutations "cause" evolution, which is not accurate. Sometimes I don't communicate my points well. GetAgrippa00:48, 13 May 2007 (UTC)
I've got to say how refreshing it is to have a respectful and intelligent discussion on this talk age that actually addresses how to improve the article, rather than the usual creationist sniping. Thank you. TimVickers19:28, 12 May 2007 (UTC)
As to the comments on homeostasis, we don't need a reference explaining what homeostasis is, instead we need a reference linking homeostasis to the process of evolution, not as an outcome of evolution. Without a reference, it is WP:OR. TimVickers17:11, 12 May 2007 (UTC)
New problems
Lead section
I'm really happy with most of the current lead section, but I notice a couple of opaque wordings have been added to the lead. Why "prevailing environmental conditions" rather than just "environmental conditions"? And "The offspring will also tend to preferentially survive and reproduce." is a very odd way to put it, as it implies that there is no cause-and-effect between the preferential survival of parents and the preferential survival of their offspring (and I don't even see the need to discuss preferential survivability so early, when smaller and simpler terms would suffice).
The mechanisms of evolution could also be better-explained: "gene flow, which is the movement of genes between populations", could confuse new readers. Discussing the exchange of variation, rather than the exchange of genes (it is in any case alleles, not genes per se, that are exchanged), would be more consistent with the previous clauses, and more likely to be understood by readers.
The speciation explanation could be a lot better, and I'm not even convinced that we need to discuss speciation much, if at all, in the lead section; evolution isn't solely on a species level. Also, "new new species"? "Similarities between", not "similarities among"; "living and extinct organisms" is redundant, and is mistakenly implied, in context, to include all possible unknown species by the contrast with the subsequent "all known species". -Silence01:14, 15 May 2007 (UTC)
Silence: some of those are my changes. "Prevailing environmental changes" is because environmental conditions can change, and thus the selective pressures can potentially change. Think global warming, for a contemporary example. "Preferentially survive and reproduce" was to get away from the common misconception of ONLY the best surviving and reproducing, whereas the reality is much subtler (usually). Fitness is a measure of relative reproductive success, not of "survival" (live and reproduce vs. die and do not reproduce.
As for your other comments, gene flow is a difficult concept at best. I'll read what's there now, but it seemed OK before. As for speciation, evolution acts at the population level, and speciation is the ultimate outcome. It does not act at other levels. "Similarities among" is my change. Basic grammar: "between" two, "among" more than two. "Living and extinct organisms" is mine also, and I'll have to check the context again. Cheers. Esseh01:33, 15 May 2007 (UTC)
But the whole point of that sentence is that organisms adapt to whatever the current environmental conditions are; when the conditions change, the adaptations correspondingly change. "Prevailing" is assumed for the same reason that things like "at the time" are: obviously an organism can't adapt to an environmental condition that doesn't exist yet, or that no longer exists! This section originally said "changing environmental conditions", but that was shortened to just "environmental conditions" because organisms also adopt to stable environments; but changing it to "prevailing environmental conditions" just seems to be making the other mistake (of implying that organisms don't change to environmental changes), and has the added disadvantage of not conveying any special information (whereas the former version made it clear that environments generally change over time—it was removed mainly because that was seen as obvious, and something to address later in the article—the new version doesn't really make any important distinction clear for the average reader).
There isn't really any such thing as "the best" in practice: natural selection is "survival of the fit" or "survival of the fitter", not "survival of the fittest". But yes, "fitter" species don't always survive—but that's why the article used wordings like "tend to survive"; if nothing else, it's easier for most readers to understand than trying to introduce new concepts like preferential survivability. Generalization isn't bad as long as we are careful to use it to clearly explain general concepts, and avoid inaccuracies. I don't see speciation as the "ultimate outcome" of evolution, because (1) there is no "ultimate outcome"; and (2) even separate species can breed at least to some extent, so if speciation is an "outcome" because it isolates two populations, then even greater degrees of interspecies divergence should be subsequent "ultimate outcomes", e.g., the level of divergence where two populations can't even reproduce infertile offspring, or can't mate at all. It just seems like there's an over-emphasis on species, which is especially problematic at the start of the article before we've fully explained what a "species" really is. I can see why you made the "similarities among" change: it's because you had to in response to your "living and extinct organisms" change. If the latter is reversed, the former can be too. -Silence01:55, 15 May 2007 (UTC)
Silence. Valid points, certainly. Some I will have to check re: the current wording. 1st: organisms can only adapt to the prevailing environmental conditions. As you state, they cannot predict what conditions will be. Changes in the gene pool under one set of conditions will not necessarily be continued if conditions change.
Re: Speciation as an "outcome", you are correct. As evolution is a continuing process, there is no "outcome, and I think I have stressed that myself. Your previous comment seemed to suggest to me that evolution could be acting on higher levels of organisms (orders, classes, etc..), whereas it clearly does not. It acts on populations, with the "outcome" on the population being the emergence of two (or potentially more) new species. Higher orders of divergence come later. Indeed, all "higher" levels or classification are abstract, and purely human constructs. Species are arguably the only "real" level of classification.
"Tend to survive" is, to me, weasel wording, and strongly implies "survival of the fittest" in its worst interpretation: live-and-breed, or die. Again, the reality is usually much subtler (rogue asteriods and dinosaurs excepted). Implying that everone (everything) not "fit" will die, is incorrect, and feeds into one of the largest popular misconceptions out there. Ultimately, it is one of the misconceptions this article should try to dispell. Just my thoughts. Esseh03:38, 15 May 2007 (UTC)
Three near-completely valueless sentences seem to have been added to the end of the lead section. Do we really need to mention evo-devo in the lead? Do we need to mention speciation again? Does "Several areas of evolution remain areas of intensive research." even have any meaning? You might as well say "Several areas of biology remain areas of intensive research." Most readers will simply be confused by this, and even the ones who understand it will not be significantly benefited.
We need to cover current research in the lead so that it is an adequate introduction to all of the article. If you think these sentences could be improved, please re-write them. TimVickers04:26, 15 May 2007 (UTC)
The claim that Lamarckism in particular, and the transmutation of species in particular, was strongly opposed by the scientific establishment seems to be nonsense. I also fail to see the value in discussing "social and religious controversy" over and over again in each paragraph; just discuss it once, if ever, in "History".
I also haven't seen any evidence that Darwin and Wallace's presentation to the Linnean society "received little attention"; perhaps it did so relative to the impact of The Origin of Species, but surely the presentation at least received significant attention within the scientific community?
"This lack of understanding of genetics posed a major problem" is anachronistic: genetics didn't exist in the 19th century. I realize that this is an attempt at foreshadowing, but it will only confuse readers, most of whom will parse the sentence to mean "ah, if only Darwin had studied genetics...".
I still don't see a section for modern evolutionary biology, discussing either its fields, current research, or recent controversies or conflicts. For that matter, I don't see a section discussing the social impact of evolutionary biology/theory in general; "social and religious controversies" should be a subsection of such a section. -Silence01:14, 15 May 2007 (UTC)
I strongly recommend discussing genetic drift before natural selection. Drift is the more "basic" process, acting on a more microevolutionary level and therefore serving as an important baseline to understand before selection can be adequately explained. Additionally, having selection immediately precede the "outcomes" section is a superb segue that I'm sure readers will appreciate.
What do you mean, "on a more microevolutionary level"? See peer review for reasoning for arrangement of these sections. TimVickers04:30, 15 May 2007 (UTC)
I mean that genetic drift exerts a stronger influence in smaller populations and timescales, while natural selection exerts a stronger influence in larger populations and timescales. Small to large is generally a more intuitive way to present ideas than large to small. -Silence13:11, 15 May 2007 (UTC)
The population is aspect is true, but irrelevant to any distinction between macro and micro. The relative importance of genetic drift and natural selection over time is not clear. Read the refs in the "genetic drift" section. TimVickers00:59, 16 May 2007 (UTC)
The "adaptation" and "speciation" sections have grown too large. In the case of "adaptation", this is because it was improperly merged with an unrelated section; in the case of "speciation", this is because it has gone into much more depth than is necessary for a basic overview of evolution like this.
I disagree, the section on adaptation needs to be re-written, but the specation section is one of the best in the article. TimVickers04:30, 15 May 2007 (UTC)
It is too detailed and technical. It is one of the worst sections in the article, for the simple reason that most people won't bother to read it. The section is ridiculously over-verbose. Compare, for example:
"In sexually reproducing organisms, speciation results from two important events. Firstly, the rise of circumstances or mechanisms that produce reproductive isolation, and secondly, genealogical divergence." vs. "In sexually reproducing organisms, speciation results from reproductive isolation and genealogical divergence."
It would be exceedingly easy to make the section readably short. Just trip the non-essential details. For starters, we do not need an entire paragraph on sympatric speciation: someone can understand evolution very well without knowing about every single little detail regarding sympatric speciation. We also don't need more than a sentence or two on parapatric speciation or peripatric speciation.
Readers don't really need to know about any type of speciation other than allopatric in order to have a very basic understanding of how evolution usually works: going deeper than that is getting into the technical details that this article is specifically not about, and consequently we should push through those details as quickly as possible. I don't even think we need an image illustrating the 4 types of speciation; if the 4 were equally common, that would be warranted, but as is it's overdone and will scare off readers with its complexity (though it is a good diagram—and one any interested parties will see when they visit Speciation, the proper article for going into this level of detail). It would probably be better to have a smaller image just illustrating one type of speciation, for simplicity's sake. Maybe we could even make it an animation (or provide a link to an animated version)?
Really, the other three types of speciation can be understood pretty easily once one has a grasp on allopatry, since they're just variants in some respects: peripatry is allopatry with unequal population sizes; parapatry and sympatry are peripatry with incomplete reproductive isolation. See how easily I explained these types of speciation in only a couple of lines? It is a major failure of the article that it does not explain them with comparable clarity and conciseness.
It's also one of the worst sections because it's highly misleading. Notice that halfway through the paragraph on peripatric speciation, the article suddenly jumps into discussing parapatric speciation, without any link to parapatric speciation or any indication for why the sudden leap occurs! This is incredibly bad form, since the overwhelming majority of readers wlil think that peripatric speciation is still being discussed; even I thought that at first, and only noticed the error because I already knew that peripatric speciation does have a "specific extrinsic barrier to gene flow". The paragraph then jumps back into discussing peripatric speciation, again without any indication, before returning to parapatric speciation in the next paragraph (with a link, as though it were being discussed for the first time).
What's happened to this section is essentially the same thing that happened to our "Natural selection" section for a very long time before I cleaned it up: we were going into far much detail because we were trying to analyze every subtype of the section without consideration for (1) the relative importance of each subtype for understanding evolution as a whole, and (2) the comprehensibility of the subtypes for your average reader, and the cumulatively increasing difficulty in understanding them as more and more detail is gone into and more and more subtypes addressed. The natural selection section is now much more balanced, and doesn't spend paragraphs, or even multiple sentences, on important but non-essential types of selection like directional, disruptive, stabilizing, etc.: it just mentions them very briefly to acknowledge and define them, then moves on before readers can get lost in technicalities. -Silence13:04, 15 May 2007 (UTC)
"Extinction" also isn't really long enough to merit a proper section; once "speciation" is shortened, it will make sense again to have speciation and extinction merged, with extinction discussed at the end of the "Speciation and extinction" section. I'm not entirely averse to having an "extinction" section, though; "speciation" needs to be shortened regardless of whether we institute a merge. The main reason I see for the merge is that extinction is not really an outcome of evolution; rather, its an environmental factor that influences evolution. That is to say, speciation, cooperation, and adaptation are just consequences of evolution occurring; extinction, on the other hand, is a consequence of the limits of biological sustainability. It isn't really a consequence of evolution, because even if nothing evolved, things would still go extinct just as much, and in exactly the same way. A merge would help avoid giving that impression.
I don't see the need to expand it. This article is already getting too long. And I didn't bring up the point that the article should address extinction's effects on evolution; I brought up the point that extinction effects evolution, but isn't really an "outcome of evolution" in any meaningful way. (It's an "outcome of evolution" in the same way that having an oxygen-rich atmosphere is, and presenting it in this way is misleading for the same reasons.) The fact that we're asking "how does extinction affect evolution?" helps show that extinction isn't best discussed as an "outcome", and thus shouldn't be a section within "outcomes": the best way to avoid confusing or misleading readers is by integrating it into another section. If we do expand the extinction section, we should in the process trim just as much unnecessary information off of it (e.g., the extinction event details, and hyperbole like "virtually all animal and plant species that have ever lived on the earth are now extinct"). -Silence13:04, 15 May 2007 (UTC)
The article is not getting too long, it only has 51 kb of readable text. This matches the guidelines given and is even on the short side for recent FAs. The statement on extinction is not hyperbole, see the citation given. TimVickers17:20, 15 May 2007 (UTC)
Cooperation is a type of co-evolution, isn't it? (Or at least involved in it in the same way that competition is.) If so, you might as well just rename the section "Co-evolution". The main rationale I could see for restoring the old title, "Cooperation and competition", is that it might be a bit easier for new readers to parse; but there's no point in going halfway about it! And the elegance of "Co-evolution" works well. Then again, it might not adequately cover the topics addressed in the section... -Silence01:14, 15 May 2007 (UTC)
Cooperation is not a type of co-evolution. Coevolution specifically refers to reciprocal evolution between different species, while cooperation specifically refers to behavioral relationships between individuals within the same species. TxMCJ03:40, 15 May 2007 (UTC)
Do you have cites to back up this distinction? The Wikipedia article on cooperation (not to mention all my dictionaries) don't mention at all any sort of interspecies requirement. Co-evolution is defined as "the mutual evolutionary influence between two species", yes, but cooperation is defined as "mutually beneficial interaction among organisms living in a limited area". That presumably includes both cooperation between species and cooperation within them. For that reason, the current title seems to be either redundant (because of overlap) or incomplete (because of the lack of the other side of co-evolution and the opposite of cooperation: competition).
It seems to be that co-evolution and cooperation/competition aren't distinct categories in the same area, as you imagine, but rather different ways of looking at the same issues: co-evolution is the selective influence exerted by two species upon each other, while cooperation is the act of two individuals working toward a common goal for mutual benefit. Cooperating individuals of different species always co-evolve; but co-evolution is far from always being cooperation.
Consequently, it seems like the current setup of the section is misleading and ambiguous. Although I was learning toward other titles at first, my current recommendation is to rename "Co-evolution and cooperation" to "Competition and cooperation", on the basis that both of these are important topics, and both can be forms of co-evolution, and they are much more common terms which our readers are more likely to immediately understand. We can still discuss co-evolution, perhaps having a short paragraph to explain the general fact that species influence each others' evolution (co-evolution), followed by two larger paragraphs dealing more specifically with competition and cooperation between species and individuals. -Silence13:04, 15 May 2007 (UTC)
Common descent is not a consequence of evolution. "Common descent" really means "common ancestry"; it is neither necessary for evolution, nor necessitated by it. In fact, it has no more to do with evolution than the existence of plants does. "Common descent" should be a top-level section (i.e., not inside of anything else), and "History of life", the next section, should be a subsection within it.
"Common descent" should also probably have subsections for "Homology", replacing the old "evidence of evolution" section, and "Phylogeny and systematics", explaining the classification of species based on evolutionary relationships—including explaining the phylogenetic tree we include twice in this article.
"Life must exist before it starts diversifying, and so..." is painfully awkward and roundabout. Abiogenesis is not often discussed under the "general header" of "evolution" by scientists in the field; it is misleading to imply otherwise. Again, abiogenesis is not biological evolution, anymore than the Big Bang is galactic evolution! That is simply a fact; indeed, more than that, it's a necessary logical truth, following from the definitions of the terms involved (at least, as they're used by the scientific community, which are the relevant definitions). This paragraph on abiogenesis should be shortened and made the first paragraph of the "History of life" section.
The sentences on microscopic organisms seem filled with redundancies. The level of detail (and technicality) both here and in discussing the rise of multicellularity in eukaryotes seems excessive. I also don't see the point of noting that unique lineages went extinct after the Cambrian explosion; unique lineages have gone extinct in every period of evolutionary history. -Silence01:14, 15 May 2007 (UTC)
You are correct that common descent is not needed for evolution, and that it is not necessitated by evolution. Instead it is an outcome of evolution. As a result of evolution, extant organisms have common descent. This is why it is in the "Outcomes of evolution" section. Microorganisms dominate the history of life on earth, if anything there is too little coverage of these organisms in the article and a POV bias towards animals and plants - which make up a minor part of the biosphere. TimVickers17:24, 15 May 2007 (UTC)
It is not an outcome of evolution! It is untrue, or at best misleading, to say "As a result of evolution, extant organisms have common descent": rather, one might say "As a result of evolution and common descent, extant organisms exhibit both homology and variation". Saying "As a result of evolution, extant organisms have common descent" is like saying "As a result of cellular respiration, extant organisms have common descent". Indeed, common descent is one of the only features life has which isn't a result of evolution! Almost every other feature of organisms is evolved; common descent is one of the only exceptions. One could hardly think of a more absurd misrepresentation, then, than describing common ancestry as a consequence of evolution.
If there was no evolution, organisms could still have just as much common descent. The same is not true for any outcome of evolution (i.e., speciation, adaptation, coevolution, etc.). An "outcome of evolution" is something that evolution causes. Evolution does not cause common ancestry! You can never "evolve into" having a common ancestor with another existing species; either you already have one or you never will. Common ancestry and descent is part of the historical backdrop which determines in what way evolution occurs in a certain situation; it is not an outcome of evolution. Common descent means "Having descended from a common ancestor"; the descended part can involve evolution (but doesn't need to!), but the "common ancestor" part has absolutely nothing to do with evolution. If life arose in five different places on Earth, it would still evolve through exactly the same processes.
Until this is resolved, I'm going to add a "factual accuracy" tag to this article, lest readers be led astray by the idea that having a common ancestor is somehow a consequence of evolution, and believe that universal common ancestry is something that "evolved" later in life's history. (If anything, it is abiogenesis and perhaps extinction, not evolution, that caused common descent.) -Silence19:24, 15 May 2007 (UTC)
Does our disagreement stem from me using this term to mean specifically "Common descent of different species" and you using it in it's broader meaning of "Common descent of any two organisms". Perhaps if we clarified what we both mean by this term we can see why we disagree? TimVickers19:46, 15 May 2007 (UTC)
I've changed the section title to "Common descent of different species" to be more precise. My reasoning is that if organisms did not evolve, then different species would not have common ancestors. However, since organisms do evolve, different species do have common ancestors. Therefore, common descent of different species is an outcome of evolution. If I understand your objection correctly, you are saying that if were multiple independent origins of life, then although groups of species would share common descent as a result of evolution, not all species would share common descent. Is this a correct summary of your point? TimVickers20:23, 15 May 2007 (UTC)
If your definition was correct, it would be impossible for me to say "me and my brother share a common ancestor", or "all members of a species share a common ancestor", or "dogs and wolves share a common ancestor"; clearly, the correct and widely-used definition is not reserved specifically for interspecies ancestry. It can apply to any organism.
We already have a section for "speciation" under "outcomes". It is ridiculous to have a "common descent of different species" section under "outcomes" for the same reason that it would be ridiculous to have a "heredity" section under "outcomes" (renamed to "heredity of different species"), or a "gene flow" section under "outcomes" (renamed to "gene flow of different species"), or a "history of evolutionary thought" section under "outcomes" (renamed to "history of evolutionary thought of humans who would not exist if not for evolution"). What matters is that common descent itself, which is obviously what the section is about, is not an "outcome" of evolution; renaming it to "common descent of species" is obfuscatory, awkward, and, since we already have a "speciation" section, redundant.
My point is that common descent/ancestry (the two are essentially synonymous, as reflected at common descent) is a historical backdrop to evolution, not a consequence of evolution. One doesn't need to even consider hypotheticals to realize the obvious fact that evolution is not the cause of there being a common ancestor for all life! Rather, evolution is the cause of life developing in the way it did from that common ancestor. The common ancestry/descent isn't the consequence of evolution; rather, the specific way that species developed from a common ancestor is such a consequence. But having such a vague section would serve no purpose, whereas having a section for common descent itself (which should be top-level, since it's not a mechanism, consequence, or source of variation in evolution) makes a lot of sense. -Silence20:58, 15 May 2007 (UTC)
Thinking critically, what does this section contribute to the article that is not duplicated elsewhere? We could move the link to "Evidence of common descent" and statement that all orgs are related by long sequence of spp events to the speciation section and delete the remainder. This would give us more space to discuss the mechanisms of evolution in more depth, which should be the real focus of the text. TimVickers21:11, 15 May 2007 (UTC)
The speciation section should be about speciation, not about common descent. Trying to cram all information about common descent into the speciation section, on the basis that "modern organisms speciated from the common ancestor" makes as little sense as trying to cram all information about common descent into the natural selection, on the basis that "modern organisms are selected descendants of the common ancestor", or trying to cram it all into variation, on the basis that "modern organisms varied in different ways from the common ancestor"; all of these are equally poor, because conflating them with common descent is equally misleading and problematic in every case. (Again, speciation could occur without common descent being true; and common descent could be true without any speciations.) Indeed, trying to pack it into speciation is the worst idea because the speciation section is already far, far too large.
Again, I see absolutely no reason not to make the common descent section a distinct top-level section, based on its importance to evolutionary theory and history, on the difficulties of trying to squeeze it into another section, and on the many valuable subsections it could easily contain (including the "history of life" and "homology/evidence of evolution" sections). It resolves every problem with the current section's organization, and frees us up to spend an adequate amount of time discussing former sections of the article, as well as issues that haven't yet had a section (e.g., systematics and phylogeny). And it would make the "products of evolution" section less overlong. -Silence21:40, 15 May 2007 (UTC)
I'm going to wait and see what some other people think about these concerns about the section arrangements. I don't see this as really that important. TimVickers22:54, 15 May 2007 (UTC)
As I said in the peer-review, I think the information on common descent would be best handled as part of the "Evolution of life" section. However I don't see a major problem with giving it a top-level heading.--BirgitteSB13:18, 16 May 2007 (UTC)
What would an "evolution of life" section consist of? That sounds a bit too vague. Isn't the entire Evolution article essentially about "evolution of life", since it's about biological evolution? If you mean something like "the history of the evolution of life", I agree that the two should be linked, though I think we can put "history of life" within "common descent" rather than vice versa, in part because it makes more sense to discuss common descent before discussing its consequences for reconstructing life's history, and in part because it allows us to discuss homology and phylogeny in the same oversection as well. -Silence15:45, 16 May 2007 (UTC)
I mean it would be best handled along with the material that currently is in the existing subsection labeled "Evolution of life". It is one of the last sections of the article. You are trying to read far to much into my suggestion. I am just using the terminology that exists in the article.--BirgitteSB17:53, 16 May 2007 (UTC)
This is a place where is may be important to distinguish between evolution as fact (empirically observed evidence that it happens) and theory. Common ancestor may not be necessary for evolution in fact, but I do know that many have argued over the necessity of this in Darwinian theory. At my former institution a visiting philosopher of science - sorry, I do not remember the name - made an compelling argument that for the modern synthesis to be true, we (living organisms) must all be descended from a common ancestor. Obviously my point is not that he is right but that this is a significant view. Whether we should have one section on the role of common ancestry in the theory, and another on our best yet reconstruction of the history of life from the first organisms to the present, well, I am inclined to treat them separately but do not have strong feelings. Slrubenstein | Talk15:51, 16 May 2007 (UTC)
I think Birgitte's suggestion is an excellent one. This could serve as a good introduction to that material on the origin of life and the subsequent divergence of organisms, since common descent is related closely to both. TimVickers18:06, 16 May 2007 (UTC)
Since most people do not have strong feelings either way, and the facts in the section are not under dispute, merely their organisation, I'm going to remove the "factual accuracy disputed" tag. If anybody does feel very strongly that this discussion about where this material should go in the article is a matter of vital importance, please feel free to replace the "disputed" tag. TimVickers18:27, 16 May 2007 (UTC)
