Talk:Evidence of common descent/Archive 2

Added section "Evidence from interspecies fertility and modifications"
Hello all, I have added a section to the article dealing with evidence from hybrids, hybrid fertility and modification. This is an area that is too often ignored, FSR. The polar bear being a rather good example. Thanks. 4.246.206.221 (talk) 05:34, 13 January 2009 (UTC)

Evidence from geographical distribution needs major work
I have been trying to improve the section on geographical distribution by adding some sourced examples. However I think to improve it any further I need to do a major overhaul and replace some of the unsourced material that is already there. The material currently there is not only usourced but frankly some of it is plain misleading. The subsection on continental distribution uses some bad examples including elephants and lions, which don't really fit because until recently they were very widely distributed. Even worse is the "Explanation" subsection, which implies that mammals reached Australia by crossing a land bridge from Asia. However, as another subsection now describes there is very good evidence that marsupials mammals reached Australia from South America via Antarctica when all 3 of those contintents were still connected as part of Godwana. Also frankly I don't care for the entire explanation subsection which doesn't make much sense to me. So unless someone else wants to fix them and provide sources I am going to rewrite the contintental distribution sub section and delete the text in the current explanation subsection. If it at all possible (if I can find a suitable source to support it) I will try and save the material on camel evolution if I can find the right source. Unless someone objects I will start the overhaul in a couple of days. Rusty Cashman (talk) 09:05, 22 March 2009 (UTC)


 * Factual Errors Found**

1. The echidnas and platypus, the only living representatives of primitive egg-laying mammals (monotremes), can be found only in Australia and are totally absent in the rest of the world.

- Echidnas are not found only in Australia. They are also found in New Guinea.

2. Other animal distribution examples include bears, located on all continents excluding Africa and Australia, and the polar bear only located nearest to the North Pole.

- There are no bears living in Antarctica.

3. Families of sirenians are distributed exclusively around the earth’s waters, where manatees are located in western Africa waters, northern South American waters, and West Indian waters only while the related family, the Dugongs, are located only in Oceanic waters north of Australia, and the coasts surrounding the Indian Ocean.

- The description of the distribution of the dugong is not accurate. —Preceding unsigned comment added by 124.149.189.103 (talk) 16:21, 23 December 2010 (UTC)

Naming of this Article
Surely, evidence of common decent implies evolution? it seems that the writers are bending over backwards too far in the titling of this article.41.245.166.208 (talk) 19:33, 15 November 2009 (UTC)
 * "bending over backwards" how, and to who? It is a list of evidence which outlines common descent, the title is factual. Darrenhusted (talk) 20:29, 15 November 2009 (UTC)
 * Common descent is different from evolution. For example, present Seventh Day Adventist doctrine accepts evolution as a process that occurs today (and the last couple thousand years) but rejects common descent (regardless of how old the universe may be, they maintain that our planet and earthly life was recently and exceptionally created, that humans and animals have been separate species always, and even that there was no suffering/death/predation in the animal kingdom prior to the original sin). So there is motivation for an article explaining, e.g, why the pentadactil limb implies more than just common design elements but actually a continuous lineage (over a billion years), why the fossil layers could not have been sorted in a single flood, that kind of thing (whereas the evidence for evolution article would be more concentrated on breeding experiments and antibiotic resistance). Cesiumfrog (talk) 08:33, 27 November 2010 (UTC)


 * (i) This thread is a year old. (ii) The Theory of Evolution has included common descent since On the Origin of Species. HrafnTalkStalk(P) 09:34, 27 November 2010 (UTC)

Whoops...
I fail at life.

I had made what was initially a revert. However, while looking through the article I ended up keeping some bits of the most recent edit, removing others, while simply rewording others, meaning my edit wasn't actually a revert but rather an edit in general - yet my summary does not indicate this. This is entirely my fault and I apologise for any confusion which may result. >.< Sorry everybody. ElijahOmega (talk) 19:01, 16 November 2009 (UTC)

Intro phrase tagged
The construct "The wide range of evidence of common descent of living things ... provides a wealth of information on the natural processes by which the variety and diversity of life on Earth developed" is logically questionable. How can "evidence" "provide" information? Evidence "is" information judged in favor of something that requires proof. What other information beyond the one given as evidence is in mind? Last, but not the least: Who and where said so? In all WP:AGF I may assume it is a clumsy summary of something smart, so I'd like to see the origin (hence my tags). - Altenmann >t 06:20, 18 March 2010 (UTC)
 * It might be hoped that the reader would notice that the Contents lists nine "Evidence from..." sections and would understand that putting a bunch of unexplained links in the lead might not be the right thing to do, however, I suppose that a generic reference would be desirable. Re the point about evidence providing information, I think anyone even skimming the article would have to agree that "a wealth of information on the natural processes by which the variety and diversity of life on Earth developed" is certainly presented, and it's unclear how to sum up that obvious point. Johnuniq (talk) 07:37, 18 March 2010 (UTC)
 * It might be hoped that I am not a complete idiot and can read, not only write. The "nine" is "evidence from" indeed, and the article does provide "a wealth of information", but this does not address my remark. For starters I would suggest you to read wikipedia article evidence. After that please ask me what exactly is unclear in my remark. Hint: please consider the difference between the following phrases: "This notable fact is an evidence (of ...)" and "This evidence (of...) is a notable fact". If you don't see any then please let someone else address my concern. - Altenmann >t 18:12, 18 March 2010 (UTC)
 * As for "bunch of unexplained links", please explain how the intro claim "evidence of common descent of living things proves the occurrence of evolution" is supported in this article. - Altenmann >t 18:15, 18 March 2010 (UTC)
 * I do not have time for a full response at the moment, but I would like to clarify that I most definitely was not attempting to make any sort of point other than what would be good for the article: by "the reader" I did not mean you; I meant that we editors could hope that the Contents would indicate to readers that the article contains the details with references, and would indicate the complexity of the case – a complexity that makes an unexplained reference on the sentence in the lead somewhat difficult. I did agree that a generic reference would be desirable. Johnuniq (talk) 07:58, 19 March 2010 (UTC)

Evidence of...
I find it odd that all the sections are titles with “Evidence of/from…” Is it necessary to have this on all sections when the article title clearly states that the article is about the “’Evidence of’ common decent”? Can’t the sections be labeled simply Genetics, Paleontology, observed speciation, etc? Thoughts? Andrew Colvin (talk) 14:51, 23 April 2010 (UTC)
 * It does look a little odd in the table of contents, but given the lengthy and detailed (and interesting) sections, I think that "Evidence from" is probably better retained to avoid confusion while reading ("Evidence from paleontology" is about the evidence rather than paleontology). Johnuniq (talk) 01:10, 24 April 2010 (UTC)
 * That’s true. Good call. It seems to be sufficient as it is so it’s a keep. Andrew Colvin (talk) 01:50, 24 April 2010 (UTC)

Evidence from observed speciation and adaptation
This section along with the latter needs more work. It has only three instances of speciation and one instance of hybrid speciation. Talk Origins has a large list (two actually) showing many observed instances of speciation—regular and hybrid.


 * http://www.talkorigins.org/faqs/faq-speciation.html
 * http://www.talkorigins.org/faqs/speciation.html

If more research was put into many of them from someone more educated on this particular subject we could have a large collection eventually deserving of its own page linking to this section. Andrew Colvin (talk) 13:58, 29 April 2010 (UTC)

The peppered moth is given as an example in this section. My understanding is that light/dark coloration in peppered moths is an example of microevolution, not speciation. Is there evidence that a speciation event is occurring? Perhaps this example should be removed from this section. —Preceding unsigned comment added by Chungdoh (talk • contribs) 17:38, 5 May 2010 (UTC)

Indeed, I was wondering myself about the peppered moth as an example of speciation -- doesn't speciation require that two non-interbreedable or at least two non-interbreeding species form? From the looks of it, the peppered moth doesn't show speciation because both the light and the dark existed before the change in selective pressure, and both existed afterwards, and they may even be able to interbreed and may not be different species. I'd suggest moving that one to an appropriate section. Of course, since no new species or even coloring came about due to the sooty change in selective pressure, I'm not even sure that the peppered moth issue belongs as an evidence of Common Descent. But I digress. Thanks. -Jesse 63.224.40.165 (talk)


 * I am not sure if this really is an example for speciation. The Peppered moth evolution page seems to suggest that it is, but it does not directly say that it is. As for the evidence of common decent, this IS an example of such. There are loads of scholarly articles on the topic. Anything in relation to biological evolution whether it be micro-macro evo, genetics, etc is evidence of common decent. Andrew Colvin (talk) 06:58, 21 May 2010 (UTC)


 * Well, if no new species came to be, then it's not an example of speciation. How is the peppered moth an example of common descent? There were two colors, the ratios changed then changed back, and in the end there was still the same two colors. It could have been white cats and black cats. Or it could have been white cats and black pigs. Both existed, and whichever color could more easily hide had a larger population.. That's natural selection to be sure - but where is any common descent demonstrated? The results (the more fit color group growing bigger) would have been the same whether they were related or completely unrelated. Fit populations grow bigger then unfit ones. I really don't see the common descent! Thanks, -Jesse 63.224.40.165 (talk) 08:57, 21 May 2010 (UTC)

Indeed, I was wondering myself about the peppered moth as an example of speciation -- doesn't speciation require that two non-interbreedable or at least two non-interbreeding species form? From the looks of it, the peppered moth doesn't show speciation because both the light and the dark existed before the change in selective pressure, and both existed afterwards, and they may even be able to interbreed and may not be different species. I'd suggest moving that one to an appropriate section. Of course, since no new species or even coloring came about due to the sooty change in selective pressure, I'm not even sure that the peppered moth issue belongs as an evidence of Common Descent. But I digress. Thanks. -Jesse 63.224.40.165 (talk)

PS: Just looking over the "Evidence from observed speciation" section some more I am bewildered. It is my goal to never fear the truth, and to find out the truth. Now, please don't anyone take this personally unless you're the perp... but: In the "Evidence from Observed Speciation" section, not only is there the listing of the peppered moth issue, but there is also the "blackcap" subsection - claiming that the blackcap [i]may[/i] form two separate species -- with no reference or citation! Disregarding the fact that everything in WP must be cited with its source, a speciation that [i]may[/i] happen (but hasn't yet happened) is not an example of observed speciation. I mean, it's pretty simple: If you haven't seen it happen because it hasn't happened yet, then it's not evidence from observation. In order for something to be evidence from observation, the thing has to have happened and been observed - and if it hasn't happened yet it hasn't been observed, and it's not evidence. Unless you can see into the future :-) (Now it would be fine if the entry could be truthfully changed to say that the blackcap HAD split into two species.)

Is this what science is coming to? What do I tell my science students? (Other then "Don't trust WP.")

I mean we all see Creationists go overboard trying to push their faith as science. But why would real scientists themselves go overboard, making absurd claims? (Like, for example, that the sooty peppered moth account is evidence of observed speciation, or that a blackcap speciation that may happen is observed evidence of speciation.) When we see a Creationist pushing his "facts" to pass off his faith as science, we understand - he's religiously driven. But what ever would cause a Scientist to behave in the same overzealous way? It's almost funny. If some poor observer didn't know any better, it'd almost look like many Scientists actually have a faith of their own - albeit perhaps a faith not involving a deity -- which drives them to push "facts" to pass off their faith as science! Anyway, there's my two and a half cents. Thanks,

PPS: "Why don't you go fix it?" you might ask. If this was the first time I saw absurdities on WP, I'd just go fix it. But experience tells me each high-exposure page on WP is babysat by somebody who likes it just the way it is and will protect absurdities with reverts. Usually they are pushing their POV. And don't tell me that POV isn't allowed -- just look around: If the editors running a certain page don't like the POV in an unreferenced claim, they delete it citing the citation-required rule. But if it fits their POV, then it needn't have a citation! (For example, the blackcap entry.) I'm not saying herein that any particular POV is right or wrong, just that it is naive to think that full-time or dedicated WP editors don't use WP to push their POV. And I'm not saying that such a situation is bad - WP is a privately owned business, and it is the right of its owner to use it to push his POV and to allow other people with whom he agrees to push his/their POV. The trouble comes when WP presents itself as NPOV when it isn't really NPOV. But that's an honesty and moral or ethical question - not a legal one - but on the other hand, I don't believe that the owner of WP even sets out to have a policy of strict honest NPOV that applies to all editors and arbitrators. -Jesse 63.224.40.165 (talk) 08:57, 21 May 2010 (UTC)
 * Assume good faith! :-) More to the point, as the detailed article shows, Peppered moth evolution is evidence of natural selection, not of speciation or common descent. As an interim measure I've commented it out, it might work under a different heading but not under the present subtitle. Also, I've added a ref for the Blackcap. Agree that it's not yet observed speciation, the links Andrew Colvin gives above point to suitable sources for improvement of this section. Improvements welcome! By the way, WP:NPOV is about fair and proportionate representation of various views in relation to their prominence among published sources by experts, WP isn't itself a reliable source. . . dave souza, talk 10:26, 21 May 2010 (UTC)


 * Thanks, Dave. That's better. Good to have a reference to the blackcap line - but the wording of "may" is still pretty shaky. Something that [i]may[/i] happen just isn't evidence for it actually having happened. In other words, "Just because it could be doesn't mean it is be..!" As to assuming good faith -- that's how I started out on WP. Imagine, me learning about WP, thinking how great of an idea it is. For years I'd seen absurd statements, and I always assumed good faith and figured there just wasn't enough people editing in order to have time to correct them. So I tried to fix a problem and I found out that the reason absurd statements existed is because somebody was protecting them! In short, it was the PIC section. There was a list of criticisms which appeared to me to be strongly biased, unfair, all of which were either not pertinent or not true - and none of which were referenced..! WP is very clear that criticisms that somebody objects to must be referenced. Anyway, to make a long story short, I started a discussion on the talk page (Read all about it), saying I thought the criticisms section needed to go (and I gave line by line reasoning as to why every entry was not up to WP standards) and pretty soon I found myself butting heads with someone who identifies himself as "Choppingmall," who seems to have a passion against PIC microcontrollers. Let me tell you, I found that one just can't expect to have a meaningful sane conversation with somebody who best identifies with a chopping mall. Just ain't gonna happen :-) Anyway, that was in 2007, and the criticisms section has been renamed Limitations and cleaned up a little bit, but still contains many of the same impertinent facts - and still has (at the time of my writing this) only one out of 12 "limitations" referenced! Thus with this incident and other observations over the years, I generally only fix spelling error stuff. For major error stuff, I generally just post to the talk page - because I've come to believe that most major errors are protected and the only way to change them is to change mind the "owner" of the page. (Yeah, yeah, I know pages "don't" have "owners" officially. But, as seen in my conversation with Choppingmall about the PIC page, pages definitely have people who maintain a page and use it to push their POV, ignoring WP guidelines for OR, NPOV, etc.) Thanks again, -Jesse 63.224.40.165 (talk) 16:14, 21 May 2010 (UTC)
 * Remember some of the audience that this page gets. Individuals that may be viewing this may be doubters of evolution. Having cited sources and quality written material is imperative. If a section is not cited well or is not even an example of the section heading, then you should get rid of it. The information might still be good so just hid it like the peppered moth section. I will try* to work on adding some more speciation events with cited sources. Our current examples could use some expertise! Andrew Colvin | Talk 18:28, 22 May 2010 (UTC)

More evidence
Here is a great lecture presentation showing a plethora of examples of evolution in different forms and processes. More research could be done finding stronger sources and more information on the topics presented to add greatly to the article.


 * http://web.as.uky.edu/biology/faculty/gleeson/BIO%20102/Online%20Lectures/ThursdayMarch252010/ThursdayLectureMar252010.pdf

Additionally, I found a journal discussing the Amphilophus citrinellus cichlid fish and its relation to others in a similar lake with fatter lips and the like.


 * http://www.biomedcentral.com/content/pdf/1741-7007-8-60.pdf
 * http://www.newscientist.com/article/dn18912-fat-lips-evolve-at-record-speed.html

Another example for the biogeography section could be lakes (or other bodies of water) that contain many endemic species such as Lake Baikal, Tanganyika, Malawi, Lake Victoria, Taal Lake, Ohrid Lake, etc.

Andrew Colvin | Talk 02:34, 23 May 2010 (UTC)
 * Sure an example of this could be Sticklebacks.--Ollyoxenfree (talk) 15:08, 12 September 2010 (UTC)

Reverts
Regarding these edits—the burden of proof is on the editor who inserts material to prove his point. Azcolvin429, you have put in blatantly false statements into this article: a map which shows marsupials occurring in Gondwana 170 million years ago, at least 40 million years before they occurred anywhere; the statement that marsupials in South America are only represented by "the opossum" (in fact, there are about 100 species of opossums, plus a couple of shrew opossums, a completely different group, and the monito del monte); the statement that "Australia has very few placental mammals" (the majority of Australia's mammals are in fact placentals, even excluding introduced species, if you include marine mammals).

I removed the "Explanation" section, because it seemed too confused and riddled with half-truths to rescue. I stand by that assessment. It starts by talking about "the main groups of modern mammal", whatever that may mean (boreosphenidans? placentals? boreoeutherians?), which arose in the Northern Hemisphere and subsequently spread over the Bering Strait (which would have brought them in, er, the Northern Hemisphere) and the Isthmus of Panama (exactly what is the period we're talking about?—this piece suggests Great American Interchange times). Then, in South America, they (placentals, I presume) led some marsupial families to extinction (as well, the article omits to mention, as a couple more placental families). They also spread to Africa over the Straits of Gibraltar (again, when?). The third route modern mammals use to spread from the Northern Hemisphere involves marsupials (which apparently weren't modern mammals in the previous line) spreading from South America (that's also in the Northern Hemisphere, I guess). Later (apparently), the Isthmus of Panama got submerged (!), isolating South American mammals. I could go on. Ucucha 20:53, 23 June 2010 (UTC)


 * I did not add any material on the biogeography except the map/s. The material that you feel is incorrect has been there for a while actually. Instead of trashing the material, why not rewrite it, adding, and removing material. You seem to have a better understanding on the topic. As for the animation map, the Talk:Marsupial article has my response to the opposition. It can easily be changed to accommodate the correct information. Andrew Colvin • Talk 21:09, 23 June 2010 (UTC)
 * You did (re)add the material by reverting me, and you ought to take responsibility for readding that material. In general, if there are concerns about the factual accuracy of a map, it would seem better to me to leave it out for the duration of the discussion, rather than risk having incorrect information in Wikipedia. As for rewriting, we're all volunteers here, and it's better to have nothing than such a bad piece as was there. Ucucha 21:16, 23 June 2010 (UTC)


 * We will leave it out and I will try to work on making that whole section better. Maybe it would be best if the subjects discussed in the "Explanation" section were used in the "Examples" section. Organisms such as Marsupials, Glossopteris, cacti and euphorbs, etc. Andrew Colvin • Talk 21:26, 23 June 2010 (UTC)


 * If it looks anything like a rat, defer to Ucucha. That's just the way it is. He knows more about rats and rat-like things that anyone on Wikipedia. :) Guettarda (talk) 21:33, 23 June 2010 (UTC)
 * The "Explanation" was apparently intended to explain the distribution of marsupials and placentals, but didn't do a really good job. I'll try to write something new later today. Ucucha 05:24, 24 June 2010 (UTC)

Should add a section
We should add a new section on Creationist Criticisms like at Unintelligent_Design —Preceding unsigned comment added by Ollyoxenfree (talk • contribs) 22:56, 5 August 2010 (UTC)


 * No. Plain and simply. This is not the article for such rubbish. This is about evidence of common decsent. Andrew Colvin • Talk 00:46, 6 August 2010 (UTC)
 * Well I saw it on other wiki articles such as Argument from poor design. —Preceding unsigned comment added by Ollyoxenfree (talk • contribs) 00:11, 12 August 2010
 * This is an article on a very well researched aspect of biology, where thousands of reliable sources are available to provide supporting evidence. If you have a reliable source providing relevant material, please say what it is. Johnuniq (talk) 04:07, 12 August 2010 (UTC)
 * Ollyoxenfree, I didn't mean to sound harsh or rude. It just isn't the place for that. However, some of your recent edits have been good and I would love to see more, and more expansion on the existing ones. :) Andrew Colvin • Talk 05:55, 12 August 2010 (UTC)
 * Sorry I'm not that good at detailed explanations I'm just good at summaries. —Preceding unsigned comment added by Ollyoxenfree (talk • contribs) 14:42, 18 August 2010 (UTC)

Genetics Really Needs Work
It is very poorly done, you need a big section on pseudogenes and other problems.--Ollyoxenfree (talk) 02:06, 22 August 2010 (UTC)
 * Oh and DNA sequencing was under biochemistry not genetics--Ollyoxenfree (talk) 02:17, 22 August 2010 (UTC)


 * I couldn't agree with you more. I think because it is a more complex subject it is avoided or less worked on. It does not really say why genetics is evidence of common decent and it is missing citations. I have an evolutionary textbook and some other materials that I could maybe read up on to maybe add to the section. Andrew Colvin • Talk 02:36, 22 August 2010 (UTC)


 * Also, DNA sequencing is under comparative physiology and biochemistry because that is what it is. However, I understand the confusion. I added a “(see…such and such) to allow for linking to the DNA seq section. Genetics is biochemistry, so I am wondering if the article needs some rearrangement to have genetics and comparative physiology and biochemistry near, linked, or combined? Andrew Colvin • Talk 02:44, 22 August 2010 (UTC)


 * I totally agree with you that biochemistry and genetics section should be merged and to whoever decides to tackle fixing it I think making of the fittest by Sean.B Carroll is a good starter book on the topic you can find a limited preview on google books which would be a good starting point. Pseudogenes is important and immortal genes both of which are found in that book.--Ollyoxenfree (talk) 17:14, 23 August 2010 (UTC)
 * I did a little expansion but it still needs work.--Ollyoxenfree (talk) 18:13, 23 August 2010 (UTC)

Ollyoxenfree, your edits to the genetics section are good, but you must understand that we don’t redundancy in the same article. I am thinking about moving the whole genetics section to the biochemistry section. The thing is that the last two sections in the genetics section really belong in biochemistry. Genetics is biochemistry, and much of the evidence of common descent lies in comparative biochemistry. That includes genetics. I think it should be moved, but I am not sure how to combine it to flow better. I will rename the heading of the section if they are combined so it allows for genetics to be incorporated into the article as a main evidence. The “Tool kit” section is good, but does not belong under the genetics section even though it is belonging to genetics. The Cytochrome c part of the preceding heading is unnecessary as it could be written in the actual Cytochrome c section.  A. Z. Colvin  •  Talk  22:07, 24 August 2010 (UTC)


 * Discard all that above! I moved sections around like crazy and combined sections to create a better flow. Do you think it works well?  A. Z. Colvin  •  Talk  22:37, 24 August 2010 (UTC)
 * Well I think that the whole category should be called biochemistry or comparative biochemistry because genetics is only one field of biochemistry and others might yield evidence for evolution too. --Ollyoxenfree (talk) 14:29, 25 August 2010 (UTC)

"Evidence from Genetics" - new subsections?
Ollyoxenfree added two new subsections to this section that aren't well-written and might deserve some further editing. Initially, I commented them out - shying away from outright deletion - but as Ollyoxenfree seems to be genuinely involved in this article, I thought it frivolous to do so. Please rewrite (as I'm in on position to do so) - the subparagraph's content may be okay, its diction isn't.

Jesus! (or whatever):

I'm twelve years old and I hope to become an evolutionary biologist.

Are you serious? If so, I'm absolutely sorry, Ollyoxenfree. At your age, I wasn't even dimly aware of the concepts outlined here and I'm sure I would not want to discuss the quality of my diction at that age. —Preceding unsigned comment added by 77.189.136.53 (talk) 20:43, 23 August 2010 (UTC)
 * Yes that is my age. So you looked at my blog, did you like it?--Ollyoxenfree (talk) 14:22, 25 August 2010 (UTC)

Nested Hierarchy
Nested Hierarchy should be added under comparitive anatomy or comparative biochemistry.--Ollyoxenfree (talk) 17:05, 29 August 2010 (UTC)


 * Elaborate?  A. Z. Colvin  •  Talk  06:29, 1 September 2010 (UTC)
 * I think he/she is alluding to the fact that the very fact that living things fit into a nested hierchy for classification purposes is an argument for common descent. Until Darwin proposed his theory of branching common descent there was no logical explanation why Apes (and humans) should be more similar to one another than to monkeys, or why Apes, Monkeys and other primates should be more similar to one another than to rodents. That is to say evolution with common descent provided an explanation why classification schemes should be able to come up with nested hierarchies like Mammals - Carnivora (bears, weasels, Dogs, Cats) - Canines (Foxes, Wolves) - Dogs; the explanation being that each sub group represented organisms that had more recently shared a common ancestor with one another than they had with the other members of the larger group above, which made classification a process of identifying evolutionary relationships. This was one of Darwin's main arguments in On the Origin of Species. There really should be an allusion to this in the comparative anatomy section. If no one beats me to it I will add something. Rusty Cashman (talk) 20:15, 1 September 2010 (UTC)


 * That is indeed an argument for common descent, and I now understand what is being said. However, with that being the case, we must have citations for such facts. We don’t want original research for what we think is evidence. I know there must be sources that speak on this topic, but make sure you have them before adding the material. I will do a bit of research on the topic as well.  A. Z. Colvin  •  Talk  21:06, 1 September 2010 (UTC)


 * I'm a he, some good things to cite are 29+ Evidence of Evolution Part 1. and I'll see what they cite.--Ollyoxenfree (talk) 01:02, 2 September 2010 (UTC)


 * It has been added, but it needs more citations and expansion.--Ollyoxenfree (talk) 01:38, 2 September 2010 (UTC)


 * I'm pretty sure that Nested hierarchies should go under Homology or Vice Versa.--Ollyoxenfree (talk) 01:54, 5 September 2010 (UTC)

Someone added a very beutiful but very lengthy quotation from On the Origin of Species to the section. With some regret I have replaced it with shorter, but I think more to the point quotation from later in the book. While the original quotion was very elegant it was awful long for this article (which is already pushing 120k bytes). I think the idea of using a quotation from Darwin there was a good one, but I think the shorter one is more compact and on point. If people feel really strongly in favor of the longer quotation I won't oppose restoring it.Rusty Cashman (talk) 00:54, 4 September 2010 (UTC)


 * I actually placed that quote and I am glad that you replaced it. I felt that it was too long and I was no way opposed to the edit.  A. Z. Colvin  •  Talk  05:08, 5 September 2010 (UTC)

Homology/Parahomology
According to 29+ Evidence for evolution vertebrate forelimbs are an example of parahomology (same structure different uses) and not homology (same structure same use), I think that should be added in the same section as homology.--Ollyoxenfree (talk) 18:32, 3 September 2010 (UTC)


 * Most scientific sources just consider it homology. The term parahomology actually occurs in a lot of creationist material when refuting homology. I think it needs to be kept the same.  A. Z. Colvin  •  Talk  21:30, 3 September 2010 (UTC)


 * Okay.--Ollyoxenfree (talk) 23:09, 3 September 2010 (UTC)
 * I agree. Homology is the traditional term for this. Rusty Cashman (talk) 00:58, 4 September 2010 (UTC)

See Also needs work
The see also section really needs work, does anybody have thoughts on how to improve it, if not done soon I will try my best on it.--Ollyoxenfree (talk) 01:50, 1 September 2010 (UTC)


 * The ‘see also’ section only needs links if it warrants it. If there enough links throughout the article that cover any extra material related to the subject, then it is unnecessary in the ‘see also’ section. If however there is a topic that cannot be integrated into the article itself, then it is useful to have that topic placed in the ‘see also’ section. See this section that has no links. Everything seems to be covered in the article, though there is always room for addition, so the section stays. It also stays because it houses the ‘Books’ link box.  A. Z. Colvin  •  Talk  06:28, 1 September 2010 (UTC)

Section 9 "works
I'm not sure if this section should be expanded or deleted does anybody have thoughts on it?--Ollyoxenfree (talk) 19:36, 26 September 2010 (UTC)
 * Two of the items belonged to a particular section, and the others appear to be sources. In light of that I've changed the heading "works" to "sources". Actually, I think that the whole page is too long. Nadiatalent (talk) 20:08, 26 September 2010 (UTC)
 * Thanks for working on that, the page is a good length considering the topic and how much evidence there is, have you seen the 29+ evidences for evolution? It's about 50 times longer.--Ollyoxenfree (talk) 00:43, 18 October 2010 (UTC)

Endogenous Retroviruses
How come I don't see endogenous retroviruses? 98.202.68.204 (talk) 04:23, 9 November 2010 (UTC)


 * What you first need is a reliable source discussing how ERVs are "Evidence of common descent". HrafnTalkStalk(P) 06:19, 9 November 2010 (UTC)


 * "29+ Evidences for Macroevolution" has a section on them, so that might be a good starting point. — tk tk  tk  23:40, 22 November 2010 (UTC)


 * I took care of it.  A. Z. Colvin  •  Talk  07:35, 21 March 2011 (UTC)

This article seems misdirected
The intended focus of this article is, I believe, the common descent of all known living organisms--which is made clear by the following statement at the article's outset: "A large body of evidence of common descent of living things has been discovered by scientists working in a variety of fields over many years."

However, in contrast to this stated focus, much of the article is devoted to presenting evidence of the common descent of organisms that are obviously related, such as (1) humans and chimpanzees (in the "Chromosome 2" discussion), or (2) various types of tetrapod vertabrates (in the "Pentadactyl limb" discussion), or even (3) modern humans (in the section entitled "Recent African Origin of Modern Humans").

Frankly, it seems rather obvious that all vertebrates are descended from a common ancestor, so why does the article devote substantial space to the common descent of various types of vertebrates--let alone to the even more obvious issue of human and chimpanzee common descent? (In fact, as I recall, with humans and chimpanzees there is somewhere between 95% and 99% of shared genetic material, depending on the methodology of the measurement).

It seems to me, as (admittedly) a lay person in the field of biology, that the more interesting question is whether, say, all archea in thermal vents, and all microbial life forms dwelling in sub-glacial Antarctic lakes, share a common ancestor with vertebrates and elm trees. The article essentially implies that this is the case, yet most of it is devoted to presenting evidence of more obvious things, like homologies of vertebrate limbs. — Preceding unsigned comment added by Pgordon2 (talk • contribs) 09:38, 11 February 2011 (UTC)


 * You stated that the article is, “…the common descent of all known living organisms…”. This is true, but not entirely true. It devoted to the evidence for the common descent of all known living organisms.


 * It is devoted because (1) a large portion of the population does not see these thing as “obvious”, (2) because detailed explanations and examples are necessary for understanding the evidence for evolution or common descent, and (3) because what seems obvious to you may not be obvious to others.


 * The article presents the evidence in the most basic way using the most obvious examples because that is what an encyclopedia does. More information could be added about the topic you suggested, but not used to replace “obvious” material.


 * In short, it is not necessarily misguided; it is explanatory for the most layperson to a more knowledgeable reader. Feel free to add more information.  A. Z. Colvin  •  Talk  19:48, 11 February 2011 (UTC)

Embryonic development
I think the embryonic development section needs to be expanded, or at least a picture to go along with the text. — Preceding unsigned comment added by NorCal764 (talk • contribs) 02:46, 20 March 2011 (UTC)


 * I could not agree more! Unfortunately, we need somebody with a little more expertise to elaborate on how embryology is evidence of common descent. It clearly is, but I think there are a lot of misunderstandings and incorrect explanations. I will try to research a bit to grasp a better understanding.  A. Z. Colvin  •  Talk  07:34, 21 March 2011 (UTC)

Pseudogenes
In the article there is a statement that 99% of human genes are ineffective and quoting a reference which I explored without finding and evidence for the statement. I originally posted a query in the place it occurred but this has been deleted and as I can't leave this page to have another look I can't be more specific about where it is or the reference - sorry (that is why I stuck my question in the text at the right place). I find the statistic unbelievable and wondered if somebody is able to check /correct it or make the reference a bit more specific, Thank you.Ppeetteerr (talk) 14:22, 4 April 2011 (UTC)


 * It's cited to http://www.genomesize.com/ . The cited information may be in that website somewhere, but should not have been included without a citation to the specific webpage containing it (otherwise finding it is like finding a needle in a haystack). HrafnTalkStalk(P) 15:03, 4 April 2011 (UTC)

Evidence from artificial selection
Common descent is macroevolution, which is when an organism's genetic code gets added to by some abnormal process e.g. mutation. Breeding animals is an example of macroevolution, which is a mixing of alleles that creates new cominations; recessive alleles can become expressed, etc. So I'm not thinking it's really evidence for common descent. Ben.kenobi.wan (talk) 17:47, 7 May 2011 (UTC)
 * Artificial selection is one of the primary examples of evidence for common descent because WE CAN LITERALLY PHYSICALLY OBSERVE, EXPERIMENTALLY TEST AND DOCUMENT LINEAGES THROUGH SEVERAL GENERATIONS. To assert that artificial selection isn't evidence for common descent simply because of personal, arbitrary redefinitions of terms is simply crude sophistry, and synthesis.--Mr Fink (talk) 18:10, 7 May 2011 (UTC)

I didn't redefine anything. From: http://en.wikipedia.org/wiki/Macroevolution:

Macroevolution is evolution on a scale of separated gene pools. Macroevolutionary studies focus on change that occurs at or above the level of species, in contrast with microevolution, which refers to smaller evolutionary changes (typically described as changes in allele frequencies) within a species or population.

Artificial selection, at least in that example of dogs used in the article, is changes within a species. You can breed Chihuahuas with Great Danes, as far as I am aware. (though they need help, because of the difference in size.) Ben.kenobi.wan (talk) 19:44, 7 May 2011 (UTC)
 * That you are trying to claim that artificial selection is not evidence for common descent because it demonstrates macroevolution, instead, is, by definition, redefining. Artificial selection is evidence for common descent specifically because we can observe and track how various lineages are descended from a common ancestor.  To argue that artificial selection somehow not evidence of common descent is as silly as arguing that ice melting into water is an example of entropy, and not thermodynamics.  Having said this, please stop soapboxing about your own redefinitions--Mr Fink (talk) 20:18, 7 May 2011 (UTC)


 * You misinterpret the article. Macroevolution and microevolution are dependent upon the same mechanisms, are both completely observable, and are the exact same thing, except for scale.  Let me give you a hint.  The second we see someone trying to separate macro and micr-evolution, we know that there's a creationist POV lurking about.  There is absolutely no difference between the two.  None.  Nada.  Nothing.   Orange Marlin  Talk• Contributions 20:19, 7 May 2011 (UTC)

Okay, I was wrong about it not being evidence of common descent.

Mr Fink: I was a little confused on some definitions ("common descent" to be specific), I wasn't being as malicious as your comments seem to imply.

Orangemarlin: What do you mean "no difference"? To get a dog from big to little is one thing, but getting a dog's descendants into something else, e.g. a cat, requires different processes. There are genes for "short" in dogs, but no genes for "cat". The genes would have to be changed somehow, not just reshuffled. And were you saying there's something wrong with being a creationist? I just take the evidence to point toward that conclusion. Ben.kenobi.wan (talk) 21:05, 7 May 2011 (UTC)
 * If you're arguing about evolution saying anything about "getting cats from dogs," then it is extremely clear that you have literally no idea what evolution is about in the first place. Dogs and cats share a common ancestor: comparisons of their genomes clearly demonstrate that, and to suggest that evolution is somehow wrong or falsified because you can't "get a cat from a dog" is childish babbling.  And yes, there is something wrong with being a creationist: being one tends to strongly prevent one from understanding science and looking at evidence in a logical manner.--Mr Fink (talk) 21:16, 7 May 2011 (UTC)

This article might benefit from a balanced selection of issues, subjects or problems contrary to the current and widely accepted theory of common descent. Alternatively, a link to other topics and controversies could be inserted near the end. Brhebert (talk) 08:33, 23 May 2011 (UTC)
 * As far as I know, there are no "subjects or problems contrary to the current and widely accepted theory of common descent" nor "controversies" that have significant scientific acceptance, that therefore should (per WP:DUE) be included in this topic. If you know of any, and can present WP:RS demonstrating that they represent a prominent viewpoint within the scientific community, then please suggest them. HrafnTalkStalk(P) 12:15, 23 May 2011 (UTC)

Article weakness
As I've demoted this again to 'C class', I should explain my reasons. Much of the content of this article addresses the issue of common descent only indirectly. Let's get some things straight. Here, we can take evolution as a given, and the mechanism as explained on several other pages on this topic. We do not have to show here that evolution occurs, nor that natural selection is the cause of adaptation. We only have to address the issue which Darwin brought forward, and others (like Lamarck) notably did not. That is, that all life alive now is descended from an earlier primitive proto-life form. Life is not composed of two or more origins, or two or more descendant trees of species. There is one tree of life (or network if you want to be fussy).

I think the only evidence which bears on this is from cellular biochemistry, cell biology and genome analysis. At any rate, anyone who thinks details of complex organisms contributes to the discussion needs to argue it out fully.

Especially silly is the inclusion of examples which do not even show speciation (such as melanism in butterflies). As the polymorphism (biology) article shows, these cases have nothing to do with speciation.

Much of the content to this article is copy-pasted from other articles. This has resulted in the restatement of points made several (or many) times elsewhere in the system. We do not need this page to do that. We need it to address its topic directly, which it scarcely does at present. Macdonald-ross (talk) 15:06, 11 October 2011 (UTC)


 * I quite agree with this analysis. The issue is not whether organisms change over time, or that they adapt to their environments. Nor is the issue whether natural selection selects advantageous genes or gene changes in organisms. Nor is showing the evolution of a certain type of animal (such as a horse) relevant to the matter of (universal) common descent. All of these things may be firmly established (as indeed they are not even controversial), even if common descent of life on earth were false. I fully agree that there is presently too much content in the article that is not directly relevant. Lindert (talk) 17:45, 11 October 2011 (UTC)

Nititating membrane
I think nictitating membrane could be added as an example of a vestigial structure in some mammals that is extant in earlier evolved forms.(mercurywoodrose)75.61.135.151 (talk) 19:16, 1 January 2012 (UTC)

Terrible Layout
This page is fairly painful to read. It is ridiculously long and the lead's text is several paragraphs. Its like getting hit in the face with a word brick. I dont know what could be done to fix this but considering the importance, there must be a better way to present the information than in a single, huge burst. I would be honestly surprised if many people made it to the end. 74.132.249.206 (talk) 03:40, 9 January 2012 (UTC)

Is this the right sort of article for wikipedia?
While this article includes lots of helpful information it seems like it's arguing for evolution instead of stating facts about the evolutionary synthesis. Wikipedia should report on controversy and report on facts but without being involved or taking a side in a controversy. This article is a collection of facts arranged to make a point, by presenting it this way Wikipedia is wading into and taking a side in the cultural controversy over evolution (put another way a list of proofs for something is only used to argue for that thing against an opponent not to convey information about a non-controversial subject). Most articles on evolution here are not like this one, they merely report on the science; Wikipedia also does report on controversy but then it explains what both sides are saying, this article belongs somewhere on talk.origins perhaps, but it does not belong here in this format. (most of the info in it should be put in other articles or in some descendant of this article with a very different format). I would start working on this but first I want to know what people think. — Preceding unsigned comment added by 63.226.178.67 (talk) 23:11, 7 February 2012 (UTC)

Wikipedia has policies about fringe theories. To treat evidence of common descent as an unsettled controversy is as fringe as denying that astronauts walked on the moon, or denying the holocaust of the Jews. Prior to modern science there were many new theories that were treated as fringe when they were first published, because the new theories conflicted with widely held religious beliefs. But during the past two centuries, massive amounts of scientific evidence has been published that conclusively prove evolution in general and common descent of humans and other apes in particular. This article presents some of that evidence. Any attempt to modify this article to treat common descent as controversial will be reverted. Greensburger (talk) 01:36, 8 February 2012 (UTC)

but don't you see? that's just my point, by its very title this article does treat common descent as controversial but then paradoxically it presents only one side of the controversy. If you want to present it as a fact rather than a controversy then a list of evidences is doing it wrong. this article seems constructed to convince creationists that common descent happened rather than just telling about it, and that is not encyclopaedic. — Preceding unsigned comment added by 63.226.178.67 (talk) 17:22, 8 February 2012 (UTC)


 * There is no scientific controversy over common decent. There hasn't been one for over a hundred years. Common decent is a major aspect of modern biology, so an article explaining the evidence for it is needed on Wikipedia. Wikipedia relies upon reliable third party sources for the information presented and has a special policy on fringe theories. There is a popular and public debate about it. There are several articles that deal with anti-evolution advocates, including Creation–evolution controversy, Intelligent Design and so forth. --Harizotoh9 (talk) 17:27, 8 February 2012 (UTC)
 * Also read the policy on undue weight: WP:UNDUE--Harizotoh9 (talk) 18:16, 8 February 2012 (UTC)

The translation of this article into German has been removed from the article name space of German Wikipedia after the discussion about deleting it de:Wikipedia:Löschkandidaten/11. Februar 2013 as there are only few creationists in Europe and the article lacks encyclopedic style and cites some non-academic sources. I think it fits better to http://rationalwiki.org because it is written as an essay to debate creationists. Matthias M. (talk) 14:24, 18 February 2013 (UTC)


 * As main author of the German translation I obviously do not share Matthias' view fully. But unfortunately I have to admit that some points in this German deletion discussion are correct although I do not think that e.g. the number of European creationists should matter in this respect. Nevertheless, the information provided has to be correct and the references need to be reliable. Thus, I might try to improve the article in this respect as my time allows before starting another attempt to include it in German Wikipedia. --Gilbert04 (talk) 22:00, 28 February 2013 (UTC)

This article is not really about common descent.
This article, which is supposed to provide information about the common descent of all species from a single organism, instead is written like a manifesto against creationism. While creationism is obviously a myth, not a scientific theory, an article on common descent is not the appropriate place to fight this battle. This article should NOT be written with the purpose of convincing creationists, or anyone else, of anything. Instead, it should be a dispassionate summary of the evidence for the common descent of all species from a single organism. What, for example, does the evolution of a horse have to do with this? In this article, it should be taken as a given, for example, that all mammals, and for that matter, all vertebrates, share a common ancestor. Anyone who doesn't believe that is operating from a basis of mythology, not science, and it should not be the mission of this article to change those individuals' minds. The more relevant issue, which is the type of thing this article should address, is whether widely-separated lineages (for example, penicillin mold and an octopus) share a common ancestor. It is probably the case that they do, but this article does not really discuss this, and instead focuses on things like genome comparisons between humans, chimpanzees, and baboons. — Preceding unsigned comment added by Pgordon2 (talk • contribs) 03:01, 15 April 2012 (UTC)
 * I completely agree with this. I came to this article to see exactly what evidence there was that there is a single common ancestor to all life. This seems to be a nearly universal assumption amongst evolutionary biologists and the like, however I have not really seen much evidence to suggest why this should definitively be the case. This article, however, did not answer any of my questions and instead only seems to provide evidence for evolution, and seems to point to the idea that evidence for evolution alone is evidence for a universal common ancestor. The implication being you apparently cannot have one without the other, without really explaining why. The closest I saw to an argument for a universal common ancestor is that life is too complex to have arisen more then once, however there was no source and again there was no explaination as to why. I would suggest that universal common ancestry is more a widely accepted hypothesis than it is a solid scientific theory, unless someone can add more definitive and well sourced evidence to this article. Otherwise the article isn't really so much about a universal common ancestor as it is about evolution in general. 184.175.49.105 (talk) 09:48, 16 May 2012 (UTC)
 * There are two related concepts, Common Descent and Universal Common Descent. The article could do a better job of separating the two concepts. For information on evidence of universal common descent, read Universal_Common_Descent. Specifically the Phylogenetic_trees based on rRNA. --Harizotoh9 (talk) 11:00, 16 May 2012 (UTC)
 * Perhaps that the article on Abiogenesis, or on the Phylogenetic tree were what you were looking for? 76.10.128.192 (talk) 07:01, 24 June 2012 (UTC)


 * I personally don't have the impression of an article against creationism, but of one linking to the various scientific areas where research has demonstrated evidence. This is precious information, and more specialized data can be found in the other articles this one links to (you can look at other articles specializing on the phylogenetic "trees of life" too).  There also might be a need to vulgarize science enough for lay readers, which includes information about the scientific process and definitions of terms such as hypothesis and theory.  That this discredits the creation myths of ancient traditions is expected, though, and avoiding this would not only require unethical censorship, but to also dismiss a lot of knowledge and facts... 76.10.128.192 (talk) 06:54, 24 June 2012 (UTC)

Just as a side note, this article used to be called "Evidence for evolution" but consensus was decided to rename it to "Evidence of common descent". I feel as if the article covers its purpose well: a collection of examples in biology that support evolution and the common descent of organisms. It may seem obscure, but I will submit that many books have been written about the topic of evolution and the evidence in support of it. The sections listed are typically cited as evidence of common descent by scientists. Common descent is not necessarily a description of "all organisms relationship to a common ancestor". Common descent in this article assumes that the evidence presented within shows that organisms evolve and descent from one another. In my opinion, each section represents this very clearly. Additionally, it appears that the article is based heavily on the talkorigins archive. My assumptions about the article have been to basically gather examples representing evolution (or what is interpreted as evidence for evolution). Maybe I am incorrect in doing so, but it appears that the information represented within is of great value!  A. Z. Colvin  •  Talk  02:28, 11 February 2013 (UTC)


 * I agree with Azcolvin429, this is of great value, and a very useful quick reference leading to more detailed articles for study. 76.10.128.192 (talk) 00:56, 12 March 2013 (UTC)

Convergence of evidence
Does anyone think there might be a good place to refer to the concept of convergence of evidence, aka consilience, in this article? I think that it's a reasonably important point (although I may be biased since I've just written a major expansion to that article), but I can't think of anywhere it might fit without disrupting the flow of the article, other than perhaps as a link under "See also." Arc de Ciel (talk) 08:18, 30 June 2012 (UTC)
 * Explaining the concept of consilience in this article seems off-topic. However, I think that article is relevant enough to be linked under "See also." SaudiPseudonym (talk) 19:44, 30 June 2012 (UTC)
 * I didn't mean that it should be explained, but that a reference might be made, e.g. as I did at Evolution as fact and theory. More generally, I thought the idea of looking at the evidence as a whole and seeing that all of it points in the same direction regardless of the method used (and that this is itself very strong evidence) might be useful in the article, which may or may not be achieved by a reference to consilience. I'm hesitant to link it under "See Also" as I think that would give it more weight than it deserves, especially since there's only one other link there at the moment. Arc de Ciel (talk) 06:35, 1 July 2012 (UTC)
 * Well, then perhaps it can be mentioned in the very first paragraph. A reference to that concept can be integrated naturally in the part explaining how this evidence supports the modern synthesis. Feel free to edit the article in any way you think is helpful! SaudiPseudonym (talk) 15:17, 1 July 2012 (UTC)
 * I thought that a place in the first paragraph would also be too much weight and probably cause problems for the rest of the paragraph. This is why I asked for comments instead of editing immediately. :-)


 * Actually, I'll drop the suggestion. I think that incorporating it effectively would require restructuring of at least some part of the article. Arc de Ciel (talk) 06:35, 2 July 2012 (UTC)

Route of the vas deferens is anatomically incorrect
It fails to explain where the seminal vesicle and the prostate gland would 'go' in the 'hypothetical vas deferens' illustration, these are important organs for the male reproductive system, and don't appear to fit in the 'hypothetical' model of the male reproductive system. — Preceding unsigned comment added by 2.220.208.103 (talk) 23:03, 13 September 2012 (UTC)

The diagram is just a simple representation of the anatomy. Additional organs are unnecessary as they would not contribute to the description of the function as a whole. Feel free, however, to create a new diagram. A. Z. Colvin  •  Talk  02:09, 11 February 2013 (UTC)

Pseudogenes
The whole paragraph on pseudogenes is clearly out-of-date and misleading. See Junk DNA.--Thucyd (talk) 14:42, 5 October 2012 (UTC)
 * Would you like to point out the purported out-of-date information, the article you cite seems to have no quandary with the pseudogenes section. I assume you may be referring to the other article stating possible functions for Pseudogenes, but the other article also accepts that; "Still, a significant amount of the sequence of the genomes of eukaryotic organisms currently appears to fall under no existing classification other than 'junk'".  If you have any other complaints, feel free to post them.--Ollyoxenfree (talk) 21:46, 12 November 2012 (UTC)

What is this article about, exactly?
I would think that at or near the beginning, there would be a definition or explanation of the meaning of the phrase "Common Descent", and that the rest of the article would somehow contrive to be about that subject. It seems to me it would be a better article if it were about something specific, in this case, the hypothesis of "Common Descent". And, if "common descent" is taken to mean that life originated on this planet, and only once, then it becomes more of a religious doctrine than a provable scientific hypothesis, because if it could arise once, why not twice? Or are we suggesting that all of the plants are related, but not to the animals? Or some similar qualification or constraint on the relatedness of all life? What really is being promoted is the idea that all of the genetic and biochemical machinery is related, in the sense that it is all backwards and forwards and sideways compatible, etc. Theodore Rigley 15:09, 4 January 2013 (UTC) — Preceding unsigned comment added by Trigley (talk • contribs)

I agree that a clear definition or explanation of the phrase "Common Descent" is needed. And we should not seem to be suggesting that plants are not related to animals. Nor should we seem to imply that common descent occurred only on the Earth. Because life formed once, it may have happened more than once on other planets having suitable environments. But that does not imply that advanced life formed more than once on the Earth, because after primative pre-cellular life formed, any later DNA, RNA, amino acids, phospholipids, etc would be consumed by or combined with the existing life forms. Likewise after procaryots developed. Greensburger (talk) 07:57, 5 January 2013 (UTC)
 * You are correct, the article should not suggest that plants and animals lack common ancestry. And as far as I can tell, it does not. Can you point to where it implies separate ancestry? Guettarda (talk) 16:48, 8 January 2013 (UTC)

Thanks, Greenburger, for the agreement;I hardly ever get that! After I wrote the above, I found the Wikipedia article "Common descent", which seems like it should be combined with this article to make one coherent whole. But I think the pro-Darwinist faction wants the Common Descent speculation to carry more weight than it can or should be asked to. For example, your last sentence above outlines a plausible speculation, and it's probably valid to think that many evidences of evolutionary processes lend it support, but it can't be proven. But so what; the life we have here and now is what requires explaining, and the means are at hand to do so. Theodore Rigley 16:21, 5 January 2013 (UTC) — Preceding unsigned comment added by Trigley (talk • contribs)


 * You might want to read evolution as fact and theory. Also, a closer read of the list of evidence in this very article, and a honest follow-up reading the related linked articles should demonstrate clearly that the Modern evolutionary synthesis is based on strong evidence and is not a mere hypothesis, and that there is no such thing as a Darwinist religion, considering the scientific method and scientific theory... 70.30.246.149 (talk) 15:07, 8 January 2013 (UTC)


 * Trigley, the purpose of this page is to focus on specific improvements to the evidence of common descent article. It would thus be useful that you (a) read the article, and (b) focus on specific changes. The common descent article is linked in the opening paragraph. You are correct that that one and this form a group - this one should rightly be considered a daughter article of that one. As for "pro-Darwinist faction", "plausible speculation" and "it can't be proven" - your choice of language suggests that you haven't read the article. Had you, you'd realise that (as as 70.30.246.149 said) "Darwinism" was replaced by the modern synthesis in the first half of the twentieth century and is really the only game in modern biology. And had you read this article, you'd realise that is anything but speculation. As for "it can't be proven" - that's simply Popperian philosophy...in normal English, if you can demonstrate something with 95% confidence, you've proven it. You can't reject common descent without rejecting almost all of modern biology, because it's all based on the same epistemological underpinnings. Guettarda (talk) 16:48, 8 January 2013 (UTC)

Thanks for responding, folks, I am genuinely interested in learning more about this subject. As your comments above might suggest, I'm not qualified to improve this article, other than by pointing out where a naive reader (me) can't readily make sense of it. The "Common Descent" article begins with this text: "In evolutionary biology, a group of organisms share common descent if they have a common ancestor. There is strong quantitative support for the theory that all living organisms on Earth are descended from a common ancestor." It would seem that this (or a better) definition could start this "Evidence for..." article. Notice that the first sentence seems to provide room for a separate origin for different groups of organisms (i.e., plants vs. animals, or maybe insects vs. molluscs, etc.) but the second sentence basically reduces to a claim for life originating just once on this planet. It seems a different thing to say that "All the organisms within this group are related" vs. "All organisms are related, period, because life originated on Earth, but only once." Now, isn't it possible that if life could have originated once, it could have done so more than once, but the biochemistry and genetics all work together so well because, well, they have convergently evolved to do so? So to me, all of the evidence cited, while compatible with a "Life originated once, etc." hypothesis, does not compel it. Theodore Rigley 16:17, 11 January 2013 (UTC) — Preceding unsigned comment added by Trigley (talk • contribs)


 * So you are asking that the article show how it is more likely to be common descent than convergent evolution? I would agree that this could be a useful point to bring up, however I would like to hear your suggestions on how exactly to word that and specific examples where you believe that extra step is necessary.--Ollyoxenfree (talk) 20:58, 11 February 2013 (UTC)


 * My previous comment (from 70.30.246.149), might have been useful, but might also have been hasty. There is evidence of covergent evolution, and hypothesis that life could have originated from space (i.e. via comets).  That said, unless I'm mistaken most of the evidence point to common descent.  Despite the discovery of covergent evolution in some features of organisms (which features) have developed more than once, those organisms appear to still have common descent.  Consider these examples.  While flight may have evolved more than once as a feature, those animals in which it evolved appear to still have ancient common lineage. 76.10.128.192 (talk) 02:38, 11 March 2014 (UTC)


 * I don't think definitions are overly important here, I would hope that people read the common descent article before reading the article about the evidence for it, Second Quantization (talk) 08:18, 11 March 2014 (UTC)