Talk:Evolution/Archive 34
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Archive 30 | ← | Archive 32 | Archive 33 | Archive 34 | Archive 35 | Archive 36 | → | Archive 40 |
Dmurtbergx made his point with peer-reviewed journals and books
Dmurtbergx provided a literature (Journal of Molecular biology,etc.)to support his contention that "Nevertheless, the proposition that biological evolution occurs through the mechanism of natural selection is completely uncontested within the scientific community." is not accurate. NPOV demands we change this to the vast majority or something similar-completely uncontested means absolute total which is not true (even if one paper it wouldn't be true-to argue otherwise is idiotic). Despite that point scientist do argue the significance of natural selection in evolution (in a particular circumstance) so even that is not accurate. It is a poor sentence and inaccurate statement. GetAgrippa 17:12, 9 March 2007 (UTC)
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Gnixon has misunderstood GetAgrippa. GetAgrippa is pointing out that scientists argue over whether natural selection is the sole mechanism through which evolution occurs. If Gnixon honestly believes that this point is equivalent to questioning whether evolution occurs, then Gnixon does not understand either English or the current state of evolutionary theory. But whether Gnixon is sincere or not, the effect is to distract us from a discussion that, as Graft has pointed out, is important, relevant to this article, and should be on this talk page. Let us stop talking about Behe, he is irrelevant to the point GetAgrippa originally made and only leads to unnecessary and wastyed talk. Slrubenstein | Talk 10:43, 16 March 2007 (UTC)
Personally, i think the easiest fix is to change the word "completely" to "virtually," and I would consider rephrasing the first clause as: "the proposition that natural selection is one of the principal mechanisms through which biological evolution occurs..." Slrubenstein | Talk 17:50, 16 March 2007 (UTC) |
- I like changing to "virtually," but the point of the sentence is to emphasize that the basic concept of evolution is not under debate within science. I've taken a shot at resolving the issue with this edit:
- Nevertheless, the idea that life on Earth evolved over billions of years from a common ancestor is virtually uncontested within the scientific community.[42]
- I think this revision fits its context and avoids the extreme "completely uncontested" phrase. The citation still may not be completely satisfactory. Also, as mentioned above, the rest of this section could use some work. Gnixon 18:07, 16 March 2007 (UTC)
I like Gnixon's version - by taking natural selection out, it makes the point unambiguous.Slrubenstein | Talk 12:28, 17 March 2007 (UTC)
Fix the body of the article
My opinion on this article is that people need to stop messing about with the lede and at least fix the obvious and minor issues with the body, such as the presence of different referencing schemes. Samsara (talk • contribs) 23:47, 12 March 2007 (UTC)
- Agreed, but there's a lot of work to get the body up to scratch, so it's probably a bit too easy to play with the lead, which is far better than the rest.
- Ah, well. When I'm feeling a little more human, I'll grab a section and work on it. Adam Cuerden talk 00:46, 13 March 2007 (UTC)
- While I'm at it, I'll make another comment, and that's that I think this article should focus on evolution, not on "things to do with evolution". Those kinds of things are what the "see also" section is usually for, which I know has been omitted from this article by consensus a while back. I would rather have a short "see also" than the kind of trailing cruft that this article suffers from. In case others may find this educational, I'll mention that this particular comment is partly inspired by reviewing the versions that were originally promoted, and, in an early FAR, kept. Samsara (talk • contribs) 01:32, 13 March 2007 (UTC)
- I think you're making a good point. Can you be more specific? Gnixon 18:19, 14 March 2007 (UTC)
- While I'm at it, I'll make another comment, and that's that I think this article should focus on evolution, not on "things to do with evolution". Those kinds of things are what the "see also" section is usually for, which I know has been omitted from this article by consensus a while back. I would rather have a short "see also" than the kind of trailing cruft that this article suffers from. In case others may find this educational, I'll mention that this particular comment is partly inspired by reviewing the versions that were originally promoted, and, in an early FAR, kept. Samsara (talk • contribs) 01:32, 13 March 2007 (UTC)
Definition of evolution is for population biology
The article is fine as an explanation of changes of population gene frequencies. You could as well have defined evolution as relating to the diversification of life on earth, and introduced natural selection as an important explanatory principle. See my addition to the intro related to cladistics and taxonomy.
Please someone correct the spelling of "cataloguing." I can't get to that text.
I am newbie on this page.
Dfarrar 13:54, 14 March 2007 (UTC)
Scorpionman
After seeing his latest edit to this article, I checked out his talk page and edit history. Can anybody tell me why this user has not been permanently blocked from editing? MrDarwin 17:25, 15 March 2007 (UTC)
- I was more impressed that Scorpionman had finally seen the light! ;) --Plumbago 17:33, 15 March 2007 (UTC)
- Alas, the shock was too much for him to take it seems, as he was apparently blocked for his own safety. But don't worry, us True Believers (tm) will continue the fight! :) Homestarmy 18:43, 15 March 2007 (UTC)
References
I just spent a few hours fixing references on this article. Luckily, I have the flu, so what else am i going to do! I'm going to take a break, but I think an article as scientific and well-done as this one, should have bad references. People make edits, and don't use even the slightest standards for referencing articles. I went along with a few other editors and used the WP:CITET method of references. I happen to like it, because it standardizes the references below. I also found references that were not really worthy of an article like this one; for example, one was essentially a link to a commercial website for seeds. I also dug up the right references in a few cases, fixed some grammar, and put in some commentary about George Bush. OK, I did not do the last one. I thought about it just to see if anyone was reading.
Anyways, can we please keep the references clean. If you notice an edit with just a web link, clean it up using WP:CITET templates. It really takes just a few moments. If you're an editor, spot check references for their usefulness, especially if it's a new edit and reference. I'm trying to be civil, but I think I'm going to make someone recite the Origin of Species backwards if they mess up the references!!!! Yeah, I'm retentive, but you have to be in my career. Orangemarlin 20:53, 17 March 2007 (UTC)
for a picture of a chicken with four legs
for a picture of a chicken with four legs see here[1].......I will add later to the article in morphological evidence CrystalizedAngels 14:26, 18 March 2007 (UTC)
- Holy S***! MarkBuckles (talk) 14:30, 18 March 2007 (UTC)
- Isn't that more likely to be some sort of siamese twin, though? Adam Cuerden talk 14:42, 18 March 2007 (UTC)
Comment: Proposal to move Evolution to Theory of evolution
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I feel as if it is best for us to move this article to Theory of Evolution for a few reasons. First of all, the name Theory of Evolution is more nuteral than Evolution. Second, many religious people may be a little offended at this being dipicted as if it is a fact. Lastly, Evolution is just a scientific theory, not a fact. Theory of Evolution would be a more correct title for this article. Peace:) --James, La gloria è a dio 22:41, 19 March 2007 (UTC)
Wow. . . Some people can be thick. . . gravity is a law. It is observable. It is testable. It is verifieable. Evolution was something someone thought of to explain why how we got here. It made sense in a time when people didn't know about DNA or that cells aren't little blobs of living substance. To get an idea of what a cell is like, imagine an entire planet ( making example large for purpose of showing intricacies)that has a computer core that directs: machines gathering materials from other planets, the making of electricity from solar energy, a defense system capable of destroying other things of equal size, and a system that starts more of the same machine out on other planets. Basically a cell is pure machinery. Incredibally complicated. Orangemarlin! ! ! Im gonna restate a truth that has been said a lot ( though not enough) evolution has not been verified whatever you say. And if creation is an unintelligent theory, why aren't the 2 arguments put side by side? The theory of evolution is stated as fact in schools by evolutionists. Creation is NOT shown to be wrong, it is only stated to be so. All evolutionists say is "this is an incorrect and stupid belief" (basically all they say about it to science students) Put both arguments side by side for everyone to see! Orangemarlin do me a favor. ( I don't really expect you to, but im requesting you to anyway) Please look into a series of movies that are called "Incredible Animals that Defy Evolution" They give one of the most well organized arguments iv'e heard. Thank you! ( and by the way I dont intend to revert to namecalling, even if someone else does, nothing destroyes the point of constructive debate as easily) ````oddball 2002
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- Previous commenters have objected to inclusion in this Talk page of questions already answered in the FAQ. There was even a proposal to move them to a special archive called 'Evolution debates'. In lieu of that, to save space here and to maintain visibility of old discussions, how about I 'box up' the above discussion using a Show/Hide pair of templates, such as {{hat}} and {{hab}}. Those names are short for {{Hidden archive top}} and {{Hidden archive bottom}}. I have done so for the above thread so you can see what it looks like. If you disagree, simply remove the pair of templates. I'll wait for feedback before doing this elsewhere EdJohnston 17:18, 20 March 2007 (UTC)
- I like this idea even better than the "Evolution Debates" archive, but others might object to it for the same reasons, i.e., that these discussions should simply be deleted. I'm worried that outright deletion (or moving to users' talk pages) will only stoke more flame wars, so I like the hat/hab archives. It would be nice if the template didn't say the archive should not be edited. By the way, this seems like a nice way to archive all long discussions, as long as the template doesn't say it can't be edited. Maybe we could consider hat/hab archiving all comments between the initial post and the final resolution (if available). Gnixon 14:31, 21 March 2007 (UTC)
Evolution statements
This article states it as fact that evolution happened. It is an unproved theory. It is simply a belief system. Anyone can call me a crazy creationist if they feel like it, but it doesn't change this. And if creation is an idiotic belief that only people who can't or won't think believe in, why not put the arguments for it and against it in schools and musems? (Please don't say that creatonists dont either. Its not true) Are the evolutionists scared of something? I think they are. And despite what evolutionists want us to belive, there are no rock layers of fossils of increasingly complicated organisms. anyone who doesnt like these statements send me a message. ````oddball 2002 —The preceding unsigned comment was added by Oddball 2002 (talk • contribs). 20 March, 2007.
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Wow. . . Some people can refuse to see the obvious. . . gravity is a law. It is observable. It is testable. It is verifieable. Evolution was something someone thought of to explain why how we got here. It made sense in a time when people didn't know about DNA or that cells aren't little blobs of living substance. To get an idea of what a cell is like, imagine an entire planet ( making example large for purpose of showing intricacies)that has a computer core that directs: machines gathering materials from other planets, the making of electricity from solar energy, a defense system capable of destroying other things of equal size, and a system that starts more of the same machine out on other planets. Basically a cell is pure machinery. Incredibally complicated. Orangemarlin! ! ! Im gonna restate a truth that has been said a lot ( though not enough) evolution has not been verified whatever you say. And if creation is an unintelligent theory, why aren't the 2 arguments put side by side? The theory of evolution is stated as fact in schools by evolutionists. Creation is NOT shown to be wrong, it is only stated to be so. All evolutionists say is "this is an incorrect and stupid belief" (basically all they say about it to science students) Put both arguments side by side for everyone to see!
Wikipedia has proof of my staement built into it. The official Evolution FAQ page says the reason that the theory of evolution is well supported by fossil evidence and the like. Its not! But it's an accepted source, and so people quote its falsehoods. Wikapedia is quite biased. but I'm ok with that. . . . . . We're used to it. 71.53.80.206 16:40, 21 March 2007 (UTC)oddball 2002
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- This issue is addressed in the FAQ. Editors should remember to keep a civil tone with each other and avoid reigniting long-settled debates. Gnixon 18:15, 21 March 2007 (UTC)
Controversial
I think this article should be tagged controversial because many people don't believe in evolution.—Preceding unsigned comment added by 68.78.117.139 (talk • contribs)
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Evolution is not a proven fact, rather a theory. It is contested by highly qualifyed scientests. Also it is not believed to be fact by everyone. I am now going to change anywere it says 'evolution is not contested by the scentific community' etc to it is, and if anyone here dosen't like that they have to first read a 'creation' and a 'Jounal of creation'. Dont be idiotic and read out of date ones, or ones not from answers in genisis. If you dont want to do research, dont change mine. There is no evedence for evolution that would turn micro-organsims into men, there is evidence for DE-volution. NuttyProSci-Fi3000 17:25, 21 March 2007 (UTC) |
- This issue is addressed in the FAQ. Gnixon 18:08, 21 March 2007 (UTC)
...the hell?
The theory of evolution by natural selection was first put forth in detail in Charles Darwin's 1859 book On the Origin of Species. In the 1930s, Darwinian natural selection was combined with Mendelian inheritance to form the modern evolutionary synthesis. With its enormous explanatory and predictive power, this theory has become the central organizing principle of modern biology, providing a unifying explanation for the diversity of life on Earth.
Why on earth has this returned? It's like a hideous vampire, returning from the dead to kill off good writing, and to keep its undead, over-edited corpse alive by feasting on the life of the article. REWRITE NEEDED BADLY!!!! Adam Cuerden talk 04:09, 21 March 2007 (UTC)
- I agree, but I put it back because rewriting is better than deletion (that is, we all agree Darwin and Mendel, etc., need to be mentioned in the intro). If it's deleted, it'll take forever for it to come back. Its festering corpse will more rapidly encourage rewriting. Graft 16:44, 21 March 2007 (UTC)
- Fair enough, but I do hope we drive the stake of rewriting through its heart soon. Adam Cuerden talk 18:40, 21 March 2007 (UTC)
- With the exception of the unexplained mention of Mendelian inheritance, I kind of liked it, though I don't think it adds much to the lead as it is now. What specifically don't you like about it, Adam? If there was a discussion of it before, can you link to it?--Margareta 21:03, 21 March 2007 (UTC)
- Various things - it didn't handle Wallace or earlier evolutionists well, the second half of it about "With its extraordinary explanatory and predictive power... central organising principle of biology, etc." bears no relationship to the first half, and, lastly, it WILL NOT DIE!!! It's the only part of the lead that's identical in phrasing to the ancient lead of a year ago, despite losing all the transition between its halves. We don't need no stinkin' Cytochrome-c in our lead. DIE YE VESTIGE OF THE EVOLUTION ARTICLE'S EVOLUTIONARY PAST! Adam Cuerden talk 21:18, 21 March 2007 (UTC)
Input appreciated
I would greatly appreciate input in discussions surrounding content of Jewish reactions to intelligent design. My interference appears to have gotten this and Jewish opposition to evolution blocked. I apologise. But I think both articles need serious attention less they waltz into OR and essay gray areas.--ZayZayEM 09:43, 21 March 2007 (UTC)
Single Last Common Ancestor
All species are not descended from a single ancestor as the introduction wrongly states. The origins of life and consequent speciation did not have just one single last common ancestor. Amongst unicellular organisms a tremendous amount of lateral gene transfer took/takes place. Intro needs to be revised Valich 06:07, 17 March 2007 (UTC)
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Personally, I've always found this terribly confusing: Are we seriously to believe that prokaryotes emerged multiple times from unique events, then exchanged things? It might be a series of convergances and divergences, but an initial single prokaryote seems hugely more likely, and the rest just muddle. Sure, I can see what it's getting at, but unless we presuppose several colonies coming together multiple times too form the proto-prokaryote, I don't see it. Adam Cuerden talk 19:56, 18 March 2007 (UTC) For clarity in confusion and consistency in all Wikipedia articles, please refer to the links added to the Horizontal gene transfer article, Speciation article, as well as the Mechanisms of Evolution section in this article, and the extremeley up-to-date scientific sources cited. Remember, science is progressive. I think it is extremely narrow-minded for us to seriously believe that all species evolved only at one particular instance in all of space and time and only arose from only one prokaryote in our vast enormous universe under all these same earlier environmental conditions, as we similarly like to, or have liked to in the past, entertain ourselves with the notion that there was or is only one God. A different subject, but the point is that there is a psychological bias that exists in the human mind to search for simplicity, and to understand Nature through concepts of simplicity, and "one" is simpler than many. One may be easier for a person to understand, but not always the truth, or, in this case, not the facts. Yes, unicellular organisms emerged from more than one LCA and new such species and strains arise today from gene transfer. Gene transfer amongst species, and not from a common ancestor, played an important evolutionary mechanism in protist evolution and in the origin of life, and still do today. While most higher species do have a common ancestor, there never was a single last common ancestor because of the tremendous amount of gene transfer occurring during the early stages of evolution. This is now an established fact in the scientific community, virtually undebated by any evolutionary biologist anymore, except by creationists: Valich 21:48, 18 March 2007 (UTC) Lake, James A. and Maria C. Riveral. (2004). "The Ring of Life Provides Evidence for a Genome Fusion Origin of Eukaryotes. Nature. Vol. 431 [[3]] UCLA Report. (2004) "Ring of Life." [[4]] Doolittle, Ford W. (February 2000). "Uprooting the Tree of Life." Scientific American. pp. 72-77. Lake, James A. and Maria C. Riveral. (1999) PNAS (Proceedings of the National Academy of Science) 96:7 pp. 3801-3806 [[5]] Bapteste et al. (2005). "Do Orthologous Gene Phylogenies Really Support Tree-thinking?" BMC Evolutionary Biology. Vol. 5:33 [[6]] Gogarten, Peter. (2000) "Horizontal Gene Transfer: A New Paradigm for Biology." Esalen Center for Theory and Research Conference. [[7]] On the birth of new species today see: Masly, John P., Corbin D. Jones, Mohamed A. F. Noor, John Locke, and H. Allen Orr. (September 2006). "Gene Transposition as a Cause of Hybrid Sterility in Drosophila." Science. Vol. 313, Issue 5792. pp. 1448-1450 Richardson, Aaron O. and Jeffrey D. Palmer. (January 2007). "Horizontal Gene Transfer in Plants." Journal of Experimental Botany. Volume 58. pp. 1-9 [[8]]
For a multiple-origin "Ring of Life" diagram in accordance to early lateral gene transfer - citation listed above - based on previous research projects at UCLA (available to scan and send) see [[11]]. See also the alternative Tree of Life based on 16sRNA by Mitchell L. Sogin of Woods Hole Marine Biological Laboratory at [[12]]. Valich 06:39, 19 March 2007 (UTC) It is just not possible to provide all the contents of every article cited. Nor is it possible to keep listing multiple citations to satisfy just a handfull of people who for some reason find this commonly accepted knowledge to be deviant or offensive or challenging to them in some way. A person has only so much time in one lifetime to devote to defense or persuasion of what they already know as fact, and actively discuss as fact amongst colleagues, before they must move on and expand in the area of research. The abstract of the last citation by Yi Chuan (2002) PMID. "The Basic Outline of the Evolution of Single Cell Life-Form." Jan;24(1):104-10. Yi Chuan summarizes the last fifty years of research in this area quite nicely [[13]]: "In 1960s, kingdoms of organisms were charted generally in a five branching form. Later, the endosymbiont hypothesis for the mitochondria and the chloroplast was proposed. The life-form is divided into two forms, the prokaryotes (bacteria) and the eukaryotes. The study of the molecular biology made the progress faster. In 1980s, Woese, CR.asserted that two-domain view of life was no longer true, a three-domain construct, the Bacteria, the Archaea, and the Eukaryotes had to take its place. At first, phylogeny trees based on differences in the amino acid sequences, then among ribosomal RNAs and also nuclear gene from hundreds of microbial species were depicted and many mini phylogenetic trees grouped the species according to their differences in the sequences. It was found that they shared genes between their contemporaries and across the species barriers. At the root of the phylogeny tree, there was not a single common cell, it was replaced by a common ancestral community of primitive cells. Genes transfered rather freely as the transposons swapping between those cells. There was no last universal common ancestor of single cell that could be found in the revised Tree of Life, It was not easy to represent the genealogical patterns of thousands of different families of genes, in one systematic map, therefor there was no trunk at all."
Valich, you're simply wrong, here. In the quote above, for example, you chose to highlight this phrase:
You'll note the final part of this clause - that could be found. That is, it is difficult to identify a LUCA due to HGT and other problems, and we may not be able to reconstruct the root of the existing tree, because it is so confused. This is ENTIRELY different from saying that there was no common origin for living things. This is what Adam is saying and what I think you're failing to understand. There is no tree of life, correct, but that does not mean that life did not have a single point of origin. This has NOT been refuted, and all the references you have posted above simply suggest that it cannot be refuted using phylogenetic methods. If you can plausibly convince us of the origin of genetic code without a LUCA, I think we'd all shut up and listen to you. Graft 16:37, 21 March 2007 (UTC) |
Not sexy enough
Anyone else find it a bit weird that we include discussion of HGT but not of sexual reproduction? Does this seem to be needlessly privileging phylogenetics? Sure, HGT confounds that, but otherwise I don't see why it's any more or less germane than sex. I seem to recall that we had sex in here in the past and excised it... anyone have any feelings on the subject? Since this is an open(ish) evolutionary conundrum as well, it maybe bears inclusion. Graft 18:53, 21 March 2007 (UTC)
- I suspect that it's because it's presumed sexual reproduction is already understood, but this is probably a bit mistaken. Still, we don't need to go into much detail - how about a paragraph on genetic recombination and independent assortment in the basic processes section? Adam Cuerden talk 19:10, 21 March 2007 (UTC)
Gah! And then nature goes and does something like this.--Margareta 17:58, 22 March 2007 (UTC)
- Very good Margareta! So much for Muller's ratchet. There are always exceptions to the rule in biology. Like bacteria (planctomycetes ) with nucleus like structures, and fish that have evolved placentas. Makes things interesting!! I noted in a recent Science edition talking about the size of genomes and abundance of non-coding DNA that it maybe proportional to the size of the cell or metabolic rate such than natural selection may select for larger genomes. They had good accordance with osteocyte size and genome size and looked at fossils and present life. Plants followed the cell size trend. Interesting reading. It reminds me of Darwin's finches beak differences, which I always assumed that the genetic variation was either influencing neural crest and bone morphogenetic protein so something directly related would be the gene in question, yet calmodulin seems to be the culprit. Examining genes and traits is not always straightforward. Back to the topic SEX! I get off track sometimes-it reminds me of the ole joke-"Meanwhile ,back at the oasis, the Arabs were eating their dates." Oops, sorry about that. I must have calligraphic Tourette's syndrome. Is there no cure??? Hee, hee, hee. GetAgrippa 18:30, 22 March 2007 (UTC)
Theory or Fact
Take a look at the following[14][15][16][17]. All these state evolution is a theory. Let me quote from the last link "Like all scientific theories, the theory of evolution is a current best explanation." It does not say it is a fact, it says it is a theory and like all theories it is the best explaination that we have. Also I have asked a science teacher that I know if Evolution is a theory and her answer was "Yes." I think she knows more about this than many of you. Thanks:) James, La gloria è a dio 00:30, 22 March 2007 (UTC)
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Please do not respond verbosely to creationist claims. It is unnecessary to debunk them in detail here. All that is needed is to cite the appropriate reference from The Index to Creationist Claims, a well-sourced reference on the subject. In this case, the "theory not a fact" fallacy is Claim CA201. --FOo 08:29, 22 March 2007 (UTC)
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- This issue has been discussed. Please see the FAQ. Gnixon 12:19, 22 March 2007 (UTC)
Evolutionary pumps
Hi there, I'd like some expert advice on this interesting theory within an article up for GA review. I've moved part of the article onto the talk page, as this doesn't match what I understand by the theory of punctuated equilibrium. Any comments on this talk page would be welcome. TimVickers 03:02, 22 March 2007 (UTC)
Cut references
These are excellent references, and would be very good for the HGT section, but are a bit much for the lead.
- Bergthorsson, Ulfar, Aaron O. Richardson, Gregory J. Young, Leslie R. Goertzen, and Jeffrey D. Palmer (December 2004). "Massive Horizontal Transfer of Mitochondrial Genes from Diverse Land Plant Donors to the Basal Angiosperm Amborella". Proceedings of the National Academy of Sciences. 101 (51): 17747–17752. Retrieved 2007-03-18.
{{cite journal}}
: CS1 maint: multiple names: authors list (link)Citing numerous additional sources, the article states in the discussion section that, "plant mitochondria frequently fuse, with their genomes recombining, which makes it easy to imagine multiple mitochondrial genes being acquired in a single event involving whole-mitochondrial transfer." This is process is relatively common and well studied in bacteria.
- Masly, John P., Corbin D. Jones, Mohamed A. F. Noor, John Locke, and H. Allen Orr (September 2006). "Gene Transposition as a Cause of Hybrid Sterility in Drosophila". Science. 313 (5792): pp. 1448-1450. Retrieved 2007-03-18.
{{cite journal}}
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- Richardson, Aaron O. (January 2007). "Horizontal Gene Transfer in Plants". Journal of Experimental Botany. 58: 1–9. Retrieved 2007-03-18.
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We should definately add these - and the references left in the lead - to the section on gene flow (encompassing HGT, hybridisation, etc) Adam Cuerden talk 11:49, 19 March 2007 (UTC)
Why are there references in the intro at all? The introduction is supposed to be a summary of the rest of the article and shouldn't contain info that isn't elsewhere in the article. The references should go in the article body. Joe D (t) 16:34, 20 March 2007 (UTC)
- Controversial topics usually end up needing them anyway, as it helps protect them from drive-by POV, by setting a "standard" that must be lived up to. Adam Cuerden talk 16:38, 20 March 2007 (UTC)
- I cut those three references but I guarantee you that someone will now put in a "need citation" tag. Then I'll put them back in, I guess? The alternative is to add in parentheses :(see: Mechanisms of evolution: New Species below)", and create a new subsection.Valich 22:44, 20 March 2007 (UTC)
- The Richard Dawkins article solved this problem by adding HTML comments stating that the reference was later in the article. Joe D (t) 11:55, 24 March 2007 (UTC)
- I cut those three references but I guarantee you that someone will now put in a "need citation" tag. Then I'll put them back in, I guess? The alternative is to add in parentheses :(see: Mechanisms of evolution: New Species below)", and create a new subsection.Valich 22:44, 20 March 2007 (UTC)
intro: suggest removing reference to "types"
The term suggests typological thinking, not required in the context. Also, many would associate speciation with reproductive isolation. I suggest "at some point diverging populations become sufficiently distinct that they may be considered distinct species, in particular if the capacity is lost for interbreeding between the populations. Dfarrar 02:47, 24 March 2007 (UTC)
Please do not use this term. It is extremely out-dated and misleading. Valich 04:35, 21 March 2007 (UTC)
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I am writing a new article on it. We do not have proof that the genetic code, as we know it on Earth, is "universal" to the universe. There are many alternative possibilities to the current genetic code, and Watson and Crick tried a host of others before finally stumbling on the correct 4-base, 3-code word, double-helix that pertains to life on Earth. There are numerous other genetic codes and the National Center for Biotechnology Information NCBI keeps a listing of all of them that I'm sure you can find somewhere on there extensive website. Children in Junior High School, and even Elementary School today learn about genetics, and I have even heard of them teaching PCR (Polymerase Chain Reaction) techniques in High School. Please give the up-and-coming younger generation some credit. There is no need to keep this article so simple-minded in thought and terminology that it not only gives innacurate and incorrect concepts, but demotes science. The article should explain evolution, but also challenge the readers' interest with thoughts and ideas and terminology that make her or him want to look up more - to understand more about this exciting field. The word "Universal Genetic Code" is an old-fashioned name for the standard genetic code and is no longer used. It was once thought that there existed just one, universal genetic code used by all living organisms. However, beginning in 1979, numerous non standard genetic codes have been discovered. Thus there is no universal genetic code and the phrase needs be avoided. "Back in the early 1970s, evolutionary biologists did think that a given piece of DNA specified the same protein subunit in every living thing, and that the genetic code was thus universal. This was unlikely to have happened by chance, so it was interpreted as evidence that every organism had inherited its genetic code from a single common ancestor. In 1979, however, exceptions to the code were found in mitochondria, the tiny energy factories inside cells. Biologists subsequently found exceptions in bacteria and in the nuclei of algae and single-celled animals. It is now clear that the genetic code is not the same in all living things." And this provides some possible evidence that all living things did not have only one single universal common origin, or a single Last Universal Common Ancestor.Valich 04:35, 21 March 2007 (UTC)
Universal is a euphemism (not universe but earth)for the ubiquitous standard code. The differences that some mitochondria, chloroplast, prokaryotes, etc exhibit is still modified from the standard code. All life ,especially plants and bacteria, demonstrate evidence of HGT, including humans. The concept of the LUCA is a theoretical construct (a grade) that most evolutionary biologist agree (recent evolutionary biology meeting described in Science) was already complex, also gene loss was probably instrumental in the birth of bacteria as well as HGT. HGT makes finding the root impractical, but not impossible. Bapteste E, Brochier C. On the conceptual difficulties in rooting the tree of life. Trends Microbiol. 2004 Jan;12(1):9-13. Review. PMID: 14700546 [PubMed - indexed for MEDLINE Lake JA, Herbold CW, Rivera MC, Servin JA, Skophammer RG. Rooting the tree of life using nonubiquitous genes. Mol Biol Evol. 2007 Jan;24(1):130-6. Epub 2006 Oct 5. PMID: 17023560 [PubMed - in process] Cavalier-Smith T. Rooting the tree of life by transition analyses. Biol Direct. 2006 Jul 11;1:19. PMID: 16834776 [PubMed - in process] Baldauf SL The Deep Roots of Eukaryotes Science 13 June 2003 300: 1703-1706 [DOI: 10.1126/science.1085544] (in Viewpoint) Toward Automatic Reconstruction of a Highly Resolved Tree of Life Francesca D. Ciccarelli, Tobias Doerks, Christian von Mering, Christopher J. Creevey, Berend Snel, and Peer Bork Science 3 March 2006 311: 1283-1287 [DOI: 10.1126/science.1123061] (in Reports) Genomics and the Irreducible Nature of Eukaryote Cells C. G. Kurland, L. J. Collins, and D. Penny Science 19 May 2006 312: 1011-1014 [DOI: 10.1126/science.1121674] (in Review).GetAgrippa 21:46, 21 March 2007 (UTC)
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Valich is right and I'm shocked that anyone would disagree with this, when Genetic Code states clearly that the canonical genetic code is not universal. One defender of "universal genetic code" seems to understand that it is not universal, but says that this term "brings up the right images". If there is no literally correct way to defend the "right image", then its probably not "right" is it? In fact, the wide distribution of the canonical genetic code, though it is not universal, leads to the inference that it is ancestral to all of cellular life. To make this inference seem definitive by loading up the rhetoric with incorrect terms is poor scholarship. Dabs 13:39, 26 March 2007 (UTC)
LUCA and the meaning of the Tree of Life diagram
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I think I may be able to add some clarity to the recent discussions of Valich's use of the 16s rRNA Tree of Life figure to support his argument that there was no LUCA. Valich has, here and in discussions on other users' talk pages, repeatedly brought up the "Tree of Life based on 16s rRNA by Mitchell Sogin of Woods Hill on the TOL Website at [[18]]" as evidence for his statement that "there is not, nor ever will be a LUCA." To quote Valich from Adam Cuerden's talk page:
He has mentioned this graphic a number of times, but I believe he is misinterpreting it and the references in the caption to it being "unrooted." To get clarification of this issue and the meaning of the term "unrooted" in the caption to the graphic, I emailed Dr. Sogin, the author of the graphic. My query to Dr. Sogin stated:
Dr. Sogin sent me a brief reply via his cell phone, which I initially posted here. He later sent me a longer reply. I am replacing the cell phone message with the longer message, as I think it is this latter that he would prefer to have posted:
I hope this is helpful. (I know you're not typically supposed to delete comments from talk pages; I hope everyone will forgive me in this one case our of respect for Dr. Sogin)--Margareta 21:23, 21 March 2007 (UTC)
There may be a misunderstanding here. The fact that the common ancestor may have been a community, rather than a single well-defined cell, does not imply a "multiple origin of life". Rather, the idea is that in the earlier stages of life (before the bacteria-archaea-eukarya separation), HGT was so rife that no single ancestral cell (indeed, no lineage) can be meaningfully identified; then, at some point, certain cells reach a degree of complexity such that HGT cannot occur to the same extent, creating independent, well-defined lineages for the first time. See Woese's paper, aptly titled "The universal ancestor."[20]: "The universal ancestor is not a discrete entity. It is, rather, a diverse community of cells that survives and evolves as a biological unit. This communal ancestor has a physical history but not a genealogical one. Over time, this ancestor refined into a smaller number of increasingly complex cell types with the ancestors of the three primary groupings of organisms arising as a result." Again, this does not imply that life has appeared independently at several locations. It does not significantly alter the general picture of common descent, either. --Thomas Arelatensis 14:30, 22 March 2007 (UTC)
There is just as much credible scientific evidence to support a "multiple origin of life" as there is to support a "single common ancestor," and if the later is going to be stated in the intro then insert a "POV-Section" tag: "Using simple stochastic models for diversification and extinction, we conclude: (i) the probability of survival of life is low unless there are multiple origins, and (ii) given survival of life and given as many as 10 independent origins of life, the odds are that all but one would have gone extinct, yielding the monophyletic biota we have now. The fact of the survival of our particular form of life does not imply that it was unique or superior." "Multiple Origins of Life." 2007 [[21]][[22]] "The possibility for multiple origins of life is an open question with profound implications for detecting life elsewhere in the universe."[[23]] "There is indeed evidence of multiple origins of life." [[24]] Wikipedia is accurate, but progressive. Most of the sources cited under single origin of life in the intro support lateral gene transfer: multiple origins, not a "single origin." Do a quick search on the net and you'll come up with over 300 sources that support or suggest the possibility of a "multiple origin" point of view. To quote George Beadle, “I have a persistent feeling that any simple concept in biology must be wrong...but...Do not discard a hypothesis just because it is simple - it might be right.”Valich 04:51, 23 March 2007 (UTC)
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Based on Thomas's suggestion, I've edited the the intro to say
- Evidence such as the wide distribution of the canonical genetic code indicates that all known cellular organisms are ultimately descended from a common ancestral population.
This is a small change from the text that was there before. Is it satisfactory to everyone? If so, the next task would be to cut most of the 4 billion citations at the end of the sentence. Cheers, Gnixon 15:07, 26 March 2007 (UTC)
- Nice, except I think the phrase "canonical genetic code" is too jargony for the lead. Can we find a phrase that is a little more accessible to the novice reader?
- Also, the last 2 paragraphs of the horizontal gene transfer section of the page could use some reworking in light of the outcome of this discussion.--Margareta 18:24, 26 March 2007 (UTC)
Proposed change
This article is a bit long, couldn't we just remove the sections that have their own articles and just link to those articles or just give a brief summary of each? It takes really long to open this on my dialup internet browser. BTW, the talk page should be archived again Ratso 01:40, 22 March 2007 (UTC)
- I don't think it is to long at all. Peace:) --James, La gloria è a dio 01:47, 22 March 2007 (UTC)
- I do ! --Thomas Arelatensis 13:17, 22 March 2007 (UTC)
- Me too! (Notice discussions above about the length issue.)Gnixon 13:20, 22 March 2007 (UTC)
- There has not been a consensus for a further reduction of the length of Evolution since the debate on 8 February. At that time, a number of previous contributors argued that it was already short enough, at around 65kb, and they suggested we not target a specific length. The article shrank a lot between mid-December and mid-January, and I agree with the February 8 consensus that it is now short enough. Though one might argue that there are still some details that might be omitted in specific sections to reduce complexity (the type of items that Silence used to call 'trivia'). The article currently stands at 71kb. EdJohnston 15:31, 22 March 2007 (UTC)
- It's a pretty complex topic: To give a proper overview needs some length, and all those references are probably extending it a fair bit.
- Anyway, I think every section has a subarticle, so that'd reduce it to... the lead and a bit of introductory material for the supergroupings. Adam Cuerden talk 18:10, 22 March 2007 (UTC)
The problem is that everyone is constantly adding their caveats and extra bits of detail, and they tend to add them too high up in the hierarchy of the article and it's sub-articles. People read the article and see their favorite topic given only brief mention, so they add several paragraphs at a level of detail better suited for a "main article." Or, they glance at the intro, see some nuance missing, and add 10 extra clauses to an already unwieldy sentence. The article naturally swells over time, so it needs to be regularly trimmed back if it's going to stay (become?) readable. (IMHO) Gnixon 15:21, 26 March 2007 (UTC)
"Sampling Error"
In the lead, can we come up with a way that "sampling error" in relation to genetic drift can be phrased in a more layperson-oriented fashion?--Margareta 18:29, 19 March 2007 (UTC)
- "...as over large numbers the random changes tend to average out, but, in small populations, the fate of any one individual (and all his genes) matters far more." - A little wordy, but you could always use half of it (large or small).Adam Cuerden talk 19:16, 19 March 2007 (UTC)
- Hmmm.... nice start, but let's keep working on it.--Margareta 19:38, 19 March 2007 (UTC)
Sometimes the easiest way to fix a troublesome phrase is to just delete it. I think the simpler sentence still gets the point across, and more detail can be included in the genetic drift article.--Margareta 18:38, 20 March 2007 (UTC)
- No, I definitely want to keep that idea in there. Drift is hard to understand and important to understand. It is ESPECIALLY important that people understand evolution as a stochastic and not a deterministic process, including selection. I think a second clause simply explaining "sampling error" might work, but I'm also not overly concerned with making the idea of "sampling error" more accessible simply by making genetic drift less so. This is the article on evolution; our allegiance should be first to clarifying ideas relevant to that. Graft 16:41, 21 March 2007 (UTC)
- Remember to balance completeness with conciseness in the introduction. Genetic drift is an important modification to the idea of evolution by natural selection, but I'm not sure it's so important that it needs to be explained in the introduction. Gnixon 18:23, 21 March 2007 (UTC)
- This is not an article about natural selection, it is an article about evolution. Graft 18:43, 21 March 2007 (UTC)
- Sorry, I wasn't clear. If I was introducing evolution to someone who hadn't heard of it, I would say something like... 1) we have all these different species because they evolved into their present forms; 2) they got there over a long period of time, mostly by natural selection picking from among random variations (this is where Darwin and everyone else went Aha!); 3) sometimes statistical effects are important, especially if populations are small (this is an importan issue if you're trying to understand evolution more deeply). I'm just saying that (3) might not make it into my introductory paragraph. I agree with Margareta's comment below. Gnixon 21:35, 21 March 2007 (UTC)
- You're right, and Margareta's right. I withdraw my objections. Graft 21:39, 21 March 2007 (UTC)
- Woot! Consensus has been reached! (Dontcha just love it when it's that easy?)--Margareta 02:02, 22 March 2007 (UTC)
- Woot-woot! Yeah, baby, consensus---go all of us. This was a good discussion. Now can we come up with a good edit for the article? Gnixon 13:25, 22 March 2007 (UTC)
- Woot! Consensus has been reached! (Dontcha just love it when it's that easy?)--Margareta 02:02, 22 March 2007 (UTC)
- You're right, and Margareta's right. I withdraw my objections. Graft 21:39, 21 March 2007 (UTC)
- Sorry, I wasn't clear. If I was introducing evolution to someone who hadn't heard of it, I would say something like... 1) we have all these different species because they evolved into their present forms; 2) they got there over a long period of time, mostly by natural selection picking from among random variations (this is where Darwin and everyone else went Aha!); 3) sometimes statistical effects are important, especially if populations are small (this is an importan issue if you're trying to understand evolution more deeply). I'm just saying that (3) might not make it into my introductory paragraph. I agree with Margareta's comment below. Gnixon 21:35, 21 March 2007 (UTC)
- This is not an article about natural selection, it is an article about evolution. Graft 18:43, 21 March 2007 (UTC)
- The reader is not going to come to an understanding of genetic drift via the lead. We want to keep them reading so they get to the more detailed sections, not have them stumble early on over unfamiliar jargon. Remember the lead is an introductory overview.--Margareta 18:54, 21 March 2007 (UTC)
- There is a difference between "simple" and "dumbed-down" ("horse with favoured odds" ??). At least a mention of genetic drift in the lead is necessary, for a simple reason: the uninitiated reader might come to believe that evolution = natural selection, a common misunderstanding that we should combat. Of course this does not mean that we should absolutely fudge a complete discussion of genetic drift in the lead. The current version seems OK to me on this point.--Thomas Arelatensis 14:17, 22 March 2007 (UTC)
- Right... The question wasn't about whether to cover genetic drift, just whether to use jargon, i.e. the term "sampling error," to describe it in the lead.--Margareta 16:08, 22 March 2007 (UTC)
- Speaking of which, I'm not wedded to that horse analogy. I just thought it was a good way to convey the mix of the action of drift and selective pressure. Feel free to ax it if you have a better notion. Graft 16:21, 22 March 2007 (UTC)
The comments from MandaClair below are relevant to this discussion. Gnixon 17:29, 28 March 2007 (UTC)