Talk:Paraphyly

message: I have removed the paragraph "The term paraphyletic is also used in historical linguistics, with similar meaning. For example, there are scholars who believe that centum and satem are paraphyletic groups of Indo-European languages".
It is so because these terms are not believed (by some linguists) to be paraphyletic but polyphyletic rather. See Talk:Indo-European languages for details. --Grzegorj 16:55, 23 August 2005 (UTC)
thread_title:  Paraphyly in linguistics? 

message: I happened upon this page again and saw that the definition had been re-broken since User:Saforrest's fix long ago (and other intervening fixes by other users). It said: "In phylogenetics, a group of organisms is said to be paraphyletic (Greek para = near and phyle = race) if the organisms have the same common ancestor, and the group does not contain all the descendants of this ancestor." I changed it to: "In phylogenetics, a group of organisms is said to be paraphyletic (Greek para = near and phyle = race) if the group contains its most recent common ancestor, but does not contain all the descendants of that ancestor." The definition was most recently broken by User:Pgan002. Please take care when rewording the definition. Roughly, all organisms on Earth have a common ancestor, and no non-trivial group of organisms contains all of the descendants of this ancestor. I also fixed the reference to Polyphyly.  A5 16:17, 19 August 2006 (UTC)
thread_title:  Definition re-broken 

message: It was shown, however, that the inclusion of ancestors in the classification leads to unavoidable logical inconsistencies
Alexei, you would have to concede that the above statement is a matter of debate even today. I think the article should be edited to highlight some of the aspects of the differing approaches. Ordinary Person 13:13, 30 November 2006 (UTC)
replies: text: Well, I said everything I could in my posts from May 27. If one can prove that exactly this or that fossil bone is the actual ancestor of some recent group it's fine with me. I only doubt it is in principle possible. As soon as we include ancestors in the scheme, some taxa turn to be inherently paraphyletic. If the whole scheme was invented to avoid paraphyly, why let it back in? Alexei Kouprianov 14:14, 30 November 2006 (UTC)

text: Well, it was. The problem is that the definition in the very first paragraph of the article is not under my full control. I am mostly active in Russian Wiki and I come here from time to time just to make few corrections here and there. Meanwhile someone usually replaces a more theoretically rigorous but somewhat obscure definition with something more agreeable from the common sense perspective. The situation is getting more complicated because an average zoologist or botanist usualy does not pay attention to such subtlities, and, especially in the textbooks, one may find rather commonsensical definitions for mono-, poly-, and paraphyly, which are a bit far from the rigorous logic of original theories back in the 1980s, when the cladistic swords weren't yet rusty being stained with blood of the pheneticists and evolutionary taxonomists... I'll try to come back in a couple of days to try and reformulate the definition agaun but I can not guarantee that it will stay for ever. (Note: I am not complaining! It is just the way the things are...) Alexei Kouprianov 18:15, 30 November 2006 (UTC)
thread_title:  Logical Inconsistencies 

message: We should define the common usage "paraphyletic to", as in "reptiles are paraphyletic to birds".  It is arguably clearer (especially for a general audience) to say "reptiles are paraphyletic, because they exclude birds" which is almost as concise, but the "paraphyletic to" wording is pretty common and baffling if you don't know the shorthand.  The only thing holding me back is that the dictionaries and glossaries I consulted only defined paraphyletic, not the usage with "to". So I don't have a source. Kingdon (talk) 19:50, 14 March 2008 (UTC)
thread_title:  "Paraphyletic to" 

message: The concept of paraphyly and paraphyletic taxa is realy quite simple. Best to start off putting cladobabble aside, to borrow Alan Kashlov's term. Cladistics may give a good picture of evolutionary progression and continuum, but it does not ordinarily give the best picure of how small groups fit within larger groups, such as how genera fit into families and families into orders. 
A paraphyletic group or taxon is simply one that does not include all its descendants, as generally stated. Examples of paraphyleitc taxa are the Nautiloidea which do not include the Ammonoidea and Coleoidea to which they gave rise; Synapsid Pelycosuaria which does not include descentant mammalia, and Dinosauria in the normal sense that excludes the derived birds (Aves)
All taxa to be valid must be monophyletic, whether one is talking from a taxonomic or cladistic perspective. In other words it must have a single common ancestor, at least generically. All valid paraphyletic taxa are also monophyletic. The terms are not muturally exclusive. One, monophyly referes to ancestory, the other, paraphyly refers to partial inclusion. I suppose a group that included all the descendants from the most recent common ancestor would be holophyletic. Mammals and birds are holophyletic because there are no exluded descendants, none having yet evolved. 
Polyphyletic taxa are another matter, in some ways the opposite of monophyletic. A polyphyletic taxon is  one with more than one most recent common ancestor, united by some convergent feature. The bird-mammal example is a fair one. Although both are warm blooded, one, birds, has its orgin in the dinosaurs, the other, mammals in the cynodonts. A better example is the Nautilida and Ammonoidea, both coiled ectocochliate cephalopods. A single taxon lumping the Nautilida and Ammonoidea exclusively would be polyphyletic, and invalidsince the Nautilida are derived from the Oncocerida and the Ammondea come from the Orthocerida. The Oncoceroda and Orthocerida are only remotely related nautiloid cephalopods just as birds and mammals are remotely related amniote tetrapods. Polyphyletic taxa, which are invalid, are the result of convergence that results in the appearance of being closely related. 
Paraphyly is an important principle in taxonomy. It keeps taxa from becoming overly diffuse to the point of having little meaning. It allows derived taxa to be asigned rank equal to that of the ancestral taxon as in Class Aves being equal to Class Dinosauria or Class Ammoidea being equal to Class Nautiloidea. Otherwise there'd be a case of diminishing returns. Paraphyly also keeps taxa in conversationally reasonable units. When we speak of dinosaurs we shouldn't have to add, non-avian. They are after all, aren't they. 
John McDonnell  —Preceding unsigned comment added by J.H.McDonnell (talk • contribs) 01:28, 25 July 2008 (UTC)
thread_title:  Paraphyly, a concept not that difficult 

message: The problem with the definition of paraphyly as stated in this article is that it is incomplete. Paraphyly also includes the groups of presently existing biological species of monophyletic groups (that is, holophyletic groups and paraphyletic groups as defined in this article) of biological species (for example humans and chimps or chimps and gorillas). Groups including ancestors are ambiguous per definition, since thing and kind (i.e., thing and its properties) are not synonymous (or equal). Things do have properties, but properties do not have things. It means that there are two kinds of monophyletic groups: holo- and paraphyletic groups. Cladistics does not understand this fact, whereas the Linnean classification system incorporates it. Mats, presently at 83.254.23.241 (talk) 09:02, 19 January 2009 (UTC)
thread_title:  The problem with this incomplete definition of paraphyly 

message: "Agnatha, jawless fish. This group contains two significant animal groups, hagfish and lampreys. Their nearest common ancestor is the ancestor of all vertebrates, so Agnatha is paraphyletic."
compare to:
"A group that does not contain the most recent common ancestor of its members is said to be polyphyletic" and "group of organisms is said to be paraphyletic if the group contains its most recent common ancestor but does not contain all the descendants of that ancestor"
Unless hagfish or lampreys include the ancestor to all vertibrates then it can't be a paraphyletic group.  If the common ancestor to all vertibrates is included in either hagfish or lampreys then the article should make this clear.
I'm not going to alter the article myself as this isn't my field and I don't know which case is the correct one.
-- Michael Mortimore  —Preceding unsigned comment added by 82.32.248.147 (talk) 08:11, 27 March 2009 (UTC)
thread_title:  Shouldn't Agnatha be polyphyletic? 

message: The article at Neomura shows that, according to Thomas Cavalier-Smith, the Eubacteria are paraphyletic (for example, bacteria such as Actinobacteria are more closely related to Neomura than they are to, say, Cyanobacteria). Should this be included? It seems significant 24.34.94.195 (talk) 01:53, 8 September 2009 (UTC)
thread_title:  Eubacteria? 

message: Wasn't the term introduced by P.D. Ashlock, entomologist at University of Kansas?
72.49.254.33 (talk) 12:00, 11 October 2009 (UTC)
replies: text: It's possible. The earliest use of paraphyletic given by the OED is the appearance in the translation of Willi Hennig's 1965 paper in Annual Review of Entomology. Do you have evidence of an earlier use by Ashlock? --Danger (talk) 18:13, 11 October 2009 (UTC)
thread_title:  Originator of term? 

message: "Before that period the distinction between mono- and polyphyletic groups was based on the inclusion or exclusion of the most recent common ancestor.  It was shown, however, that the inclusion of ancestors in the classification  leads to unavoidable logical inconsistencies, and, in some schools of taxonomy, the phylogenetic pattern is described exclusively in terms of nested patterns of the sister group relationships between the known representatives of taxa without referring to the ancestor-descendant relationships."
What logical inconsistencies? What schools of taxonomy? Do you mean most recent of last common ancestor? Just what do you mean? If you follow sister group it takes you to cladistics and there sister group is defined as part of a clade. Why is known emphasized? Really, this unreferenced passage says nothing comprehensible at all, and it would not help to throw in a reference, much less a whole book without page numbers, such as Simpson. Reference what? At this point I have to say, either do it right or do not meddle.Dave (talk) 15:07, 24 January 2010 (UTC)
thread_title: Gobbledeygook

message: Hello Tim. I got on this article from linguistics myself, as I saw linguistics terms being tossed casually around there. Historical linguistics is using the family tree model, which naturally developed into phylogeny. However, biological classification is in a state of flux so we want to be careful how far to extend the analogy. But I found that the biological articles couldn't even be understood. As to your changes, they are not the best changes to make. Yes, something on linguistics should be in there. You are getting a bit ahead of me. I was going to do it, but first things first. No, it does not belong at the top of the page. This is primarily a biological not a linguistics article. Moreover, you're not saying anything about it. We need to define what it means when paraphyly is applied to linguistics. Merely quoting another WP article I believe is against the policy. WP is NOT a source for WP articles unless they are about WP. Now, we are not lacking in linguistics in these cladistics articles. Check Cladistics. In each case the linguistics is mentioned under non-biological uses at the bottom. So, I'm moving you to the bottom. Moreover, since you have said nothing, there is nothing to move. So, I;m taking out your quote of the WP article. We need a place holder, however, so I'm putting in a single introductory statement. Anyone including you can expand it, but I have to warn you it is a steep subject so if you are not prepared perhaps you should wait for someone else. For myself I thought, first let's get the biology clear and then we can take on the linguistics. Finally, you took the picture from the top. Unless you have a better biological picture I am putting it back on top. Thanks for your interest in the topic.Dave (talk) 13:05, 25 January 2010 (UTC)
replies: text: I added a reference to the linguistics section.  I will say this, though, in my personal experience, most historical linguists would not use the term.  Really, only the very small subset who also use computational phylogenetic methods would ever use the term. --Limetom 03:05, 18 April 2010 (UTC)
thread_title: Insertion of linguistics by tim

message: This never got responded to; we rather drifted into more complex matters. I think it is implicit in the definition of a paraphyly that it's not a monophyly, and you can't avoid this. But then you'd expect me to say this because I think the decision process is:
:#Is it a monophyly?
:#If no, is it a paraphyly?
:#If no, it must be a polyphyly.
:Whereas the discussion below suggests to me that you think it's possible for a group to be none of the three. Peter coxhead (talk) 19:00, 21 June 2012 (UTC)
thread_title: Back to your original point

message: Please see Talk:Monophyly#Why_have_three_articles where I have asked why there should be separate articles on monophyly, paraphyly and polyphyly. Please leave comments there. Peter coxhead (talk) 15:57, 6 December 2010 (UTC)
thread_title:  Why have three articles? 

message: The article was saying : "Invertebrates are defined as all animals other than vertebrates, although vertebrates are derived from this larger group".
I removed "larger", because it implies that vertebrates are a subset of invertebrates.Stefan Udrea (talk) 10:37, 15 January 2011 (UTC)
thread_title:  Vertebrates derived from invertebrates 

message: I need to explain why I am reverting this recent good-faith change to the lead.
In the edit summary, the editor claims that "this article is about the biological meaning, and the introduction should reflect that rather than attempting to be a dictionary definition encompassing all meanings." A good dictionary definition, though, does not encompass meanings; a dictionary entry typically lists several meanings and provides a precise definition for each. The most prominent difference between the old text and the new is that the reference to paraphyly in linguistics has been omitted, in accordance with the editor's claim that the article is about the biological meaning.
To support this change, some argument is necessary to the effect that there is a specifically biological meaning; that paraphyly is not, univocally, an attribute both of groups of biological taxa and of language families. According to Wikipedia, there are five kinds of wine presses, but all five are wine presses in the same sense; similarly, the Paraphyly article has been assuming that there is a single sense in which both kinds of groups can be paraphyletic.  The burden of proof, I submit, is on those who maintain that a term is ambiguous. Anyone who proposes that there are five senses of "wine press" needs to make a case for the ambiguity before editing that article.
In addition to dropping the reference to linguistics, the editor has made a number of stylistic changes. Some of these are constructive, like the use of paraphyly instead of paraphyletic in the first sentence.  Others, though, I take issue with. The editor has
::
Changed from	. . .if the group consists of all the descendants of the  last common ancestor of the group's members. . . .
to          	. . .applying to groups in which all members are descendants of a single most recent common ancestor. . . .
It was I who replaced  with  sometime back. I am accepting the statement in the Most recent common ancestor article that "most recent common ancestor" is usually used to describe a common ancestor of individuals within a species while "last common ancestor" typically means a common ancestor between species. As the article does discuss both, a link to it is appropriate, but "last common ancestor" is best used in the Paraphyly article.
(Incidentally, this is an article where ambiguity is acknowleged and the different senses are intelligently discussed.  Perhaps, even if "paraphyly" is ambiguous, both senses can be treated in the same article?)
Further, not every last common ancestor will do. As I have argued  above, a definition that does not identify the group of which the LCA is being considered is inadequate.  I have revised the lead to specify the LCA of the group's members; this meets the objection.  This qualification should not be dropped.
Continuing, the editor has
::
Changed from	. . .minus one or more  monophyletic groups of descendants. . . .
to          	. . .excluding one or more  monophyletic subgroups of descendants, which are themselves groups only of descendants of a single most recent common ancestor. . . .
The clause "which are. . .ancestor" is redundant and clutters up the formulation; it has already been said that the group(s) in question are monophyletic.
Finally, the last sentence of the revised lead contains the archaic word "descendancy", which is not helpful.
Peter M. Brown (talk) 18:11, 16 July 2012 (UTC)
replies: text: Although the editor's changes were well-intentioned, I support the reversions noted above. Peter coxhead (talk) 08:03, 17 July 2012 (UTC)

text: – actually, as I've argued above, I think there are more than two senses. Firstly there is a division between "tree geometry" definitions and "character" definitions. Then the "tree geometry" definitions vary in tightness: the widely quoted very loose definition says only that one or more clades are excluded. This is often tightened by requiring the LCA to be in the paraphyletic group. I think that only Oosterbroek's 1987 definition is watertight, but it has rarely if ever been used. I'm still not sure that I fully understand the relationships between all the different definitions in the literature, but at some point these do need discussing in the article to ensure coverage, balance and neutrality. Peter coxhead (talk) 08:03, 17 July 2012 (UTC)
thread_title:  Proposed revision to the lead 

message: Without wanting to restart old controversies, the first sentence of the lead is much less helpful than the second; and unfortunately, it's the first one that pops up when a link to the article is moused over (if you have that feature switched on). Could we either cut the incomprehensible first sentence, move it after the second sentence, or rewrite it? Chiswick Chap (talk) 10:41, 25 October 2014 (UTC)
replies: text: For the record, the first sentence in question was  This bit of the sentence "where one separates from other groups at a common origin point" makes no sense to me. One what? One group? If so, this is wrong because paraphyly can involve the exclusion of more than one clade. What "common origin point"? It has to be the most recent common ancestor. I'm removing the entire first sentence. Peter coxhead (talk) 11:30, 26 October 2014 (UTC)
replies: text:  Thanks. That's much clearer. Chiswick Chap (talk) 12:02, 26 October 2014 (UTC)
thread_title: Replace incomprehensible first sentence?

message: I have restructured the best of the examples as text (per WP:LISTDD), and removed the many uncited examples (per WP:V and WP:RS). This is an article on a theoretical topic, not an opportunity for multiplying WP:OR, nor adding favourite examples ad infinitum. Obviously there are very many possible examples (thousands, certainly), but it is not this article's job to list them all, nor would that be possible even if it were not hopelessly indiscriminate. The purpose of examples is to illustrate principles, and the text and images already do that clearly and adequately. If there is an unusual instance cited in the literature, that might be added; long lists are unconstructive and inappropriate, even worse if largely uncited and repetitive of a carefully-edited text. Chiswick Chap (talk) 21:29, 1 May 2018 (UTC)
replies: text: The examples of paraphyletic groups given in the list are taxonomic terms that can be found in the biological literature. It is therefore appropriate for a reader to know their paraphyletic status, as well as the corresponding monophyletic groups. Of course, many of these examples have been provided without citation, but this can be improved. Moreover, in an encyclopedic perspective, it is informative to make available and to detail the paraphyly / monophyly information of numerous groups. -- Manudouz (talk) 08:26, 2 May 2018 (UTC)
replies: text: The status of "numerous groups" should be detailed at the articles about those groups. I entirely agree with : all that is needed here are some carefully chosen and well referenced examples. I suppose there could be a separate article "List of paraphyletic taxa" but sourcing would be an issue. Peter coxhead (talk) 08:35, 2 May 2018 (UTC)
replies: text:  Well, the uncited listcruftisation is continuing, attracted by the tempting list. I've therefore taken the bull by the horns and removed it. The article is already perfectly well illustrated with examples sufficient to make its point; the list is by its own admission permanently incomplete, of indefinite size; and we're better off without it. Sorry but there it is, we've tried hard to make use of it, but it's incompatible with having this as a decent article. Chiswick Chap (talk) 15:50, 22 September 2018 (UTC)
replies: text:  I agree entirely.  as I said above, there could in principle be an article "List of paraphyletic taxa" but each and every entry would need to be sourced. Peter coxhead (talk) 16:33, 22 September 2018 (UTC)
thread_title:  Uncited lists 

message: "Animal" in most languages is informally used by laypersons to exclude humans: compare definitions 1 and 2 here <https://en.wiktionary.org/wiki/animal>. As such, the common non-scientific use of "animal" to mean "non-human animal" is generally paraphylitic. Is it worth including this as a linguistic note? 95.184.99.80 (talk) 09:47, 23 April 2019 (UTC)
replies: text: If you find a source explicitly noting it as paraphyletic, then addition could be considered. CMD (talk) 14:01, 23 April 2019 (UTC)
replies: text: It would be odd to call this group "paraphyletic", which is more usually used when the removed clade has an obvious recent last common ancestor with the remaining taxa. ("Apes", meaning Hominidae minus Homina, are an obvious example.) Peter coxhead (talk) 15:12, 23 April 2019 (UTC)
replies: text: What do you mean by that? Humans form a clade with with chimpanzees, with a more recent ancestor than with the other apes. CMD (talk) 10:57, 24 April 2019 (UTC)

text: Humans share a common ancestor with all other animals so animals (used in that exclusionary common usage) are paraphyletic with respect to humans. But animals would never be used that way in a phylogenetic study and paraphyly only has meaning in a phylogenetic context.    Jts1882 | talk  14:33, 24 April 2019 (UTC)
thread_title: Non-human animals

message: :The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.
The result of the move request was: withdrawn by nominator. (closed by non-admin page mover) — Ceso femmuin mbolgaig mbung, mellohi! (投稿) 15:23, 1 November 2023 (UTC)
replies: text: Paraphyly →  – More directly describes the thing we're trying to document. It seems to me that the current name complicates defining the concept. Isaac Rabinovitch (talk) 02:46, 27 October 2023 (UTC)

text: I do agree, however, that there are issues with the three "phyly" articles. The problem, in my view, is not the title of the article, but the separation of the three. It's not possible to understand one concept without the others. Peter coxhead (talk) 06:30, 27 October 2023 (UTC)
replies: text: Interesting point. If you want to turn this into a discussion of merging the three articles, I'm fine with that. Can we start with discussing what the merged article would be called? Isaac Rabinovitch (talk) 15:24, 27 October 2023 (UTC)
replies: text:  you've identified the problem! The idea of merging has been discussed on and off for years, but there's never been a good idea for a title that I've seen. Peter coxhead (talk) 06:29, 28 October 2023 (UTC)

text: Re the older/alternative view of terminology, I've long wanted to get the table at User:Peter coxhead/Work/Phyletic terminology#Comparison of terminology into an article, but it didn't really seem to fit when we have three articles. Certainly the non-Hennig use should be discussed; it relates to paraphyly as well as monophyly. Peter coxhead (talk) 06:40, 28 October 2023 (UTC)
replies: text:  I'd support including that table and agree it fits better within a broader article. Have you seen these papers by Mats Envall (2008; ) and Damien Aubert (2015; researchgate)? I don't pretend to understand the latter,  but with your background you might. —  Jts1882 | talk  08:45, 28 October 2023 (UTC)
replies: text: The Mats Envall paper I have seen, but not the Aubert paper, which is interesting. The problem (for me) is that Aubert is just one of a number of authors who have produced consistent and water-tight definitions of the "phyly terminology", but there's no evidence that the wider community of biologists have taken any notice. Thus if you try to write about how the terms are actually used, you run into problems. We spent quite a lot of time discussing this on Wikipedia about 10 years ago now. Sigh... Peter coxhead (talk) 09:26, 28 October 2023 (UTC)

text: I approve Aubert's point 7: "The desire for taxonomic stability should be reaffirmed by explicitly prohibiting the use of paraphyly ... as a pretext to change the delimitation of a taxon. It is an irrelevant criterion." Sadly I see no likelihood of this being adopted. Peter coxhead (talk) 11:32, 28 October 2023 (UTC)

text: Pretty strong consensus against my proposal. I don't think we need to wait 7 days to close this. Isaac Rabinovitch (talk) 18:17, 28 October 2023 (UTC)
thread_title:  Requested move 27 October 2023 

message: The article starts out by saying that "Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and most of its descendants", but it isn't clear how the cyan patch in the diagram to the right, said to be a paraphyly, contains "most" of the descendants of the last common ancestor. "Most" in what sense? 2A00:23C8:7B0C:9A01:3E:A303:E9E2:6E46 (talk) 15:27, 20 March 2024 (UTC)
replies: text: It would be better to say most of the descendant lineages, although I'm not sure most is correct in all cases. The diagram is trying to show several things at once which makes it less clear that the paraphyletic group includes two of the three main lineages. —  Jts1882 | talk  16:08, 20 March 2024 (UTC)
replies: text:  On that basis, I changed it to "the grouping's last common ancestor and some but not all of its descendant lineages". If this is definitely worse than the previous text then please put it back.  — Preceding unsigned comment added by 2A00:23C8:7B0C:9A01:5930:A740:C4C4:BD56 (talk) 23:01, 21 March 2024 (UTC)
thread_title:  "most" descendants?