Talk:Linnaean taxonomy

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Putting in Arthropoda has made me wonder whether we shouldn't be using common names first. Here are my thoughts:

  • Some groups have had their Latin names broken by being moved around. For instance, the dinoflagellates have had several names which often differ in senses. Also, many groups show slight variations in suffices, eg the Nemertea vs the Nemertina.
  • Some groups just don't have common names available to us. Loricifera are sometimes referred to as Loriciferans, but this is secondary from the Latin and not much used, since the creatures are poorly known. On the other hand, the Hymenoptera have no common name because they are too diverse, usually labelled something like "bees, ants, wasps, etc."
  • In a few cases the anglicized version of the Latin name is more common than the Latin name itself, but still clearly derived from it. Do a search for Arthropoda vs arthropods and you will see. However, it is very hard to know how to draw the line between such things and things like the Loricifera.
  • In a few cases the group has a common name, but one which is often used in a different sense. Flies are a good example - the term is often taken to be a synonym for the Diptera, but it is not at all uncommon for mosquitoes to be considered something separate from flies.
  • There are a lot of groups where the common name is going to be unbelievably prevalent over the entirely synonymous Latin name. A page entitled beetles is going to be linked and searched to about fifty thousand more times than a page entitled Coleoptera. And, of course, it can be rendered singular, so that something is a beetle rather than a member of the Coleoptera.
  • Redirects are useful but a nuisance to go through, and it's very hard to keep track of a mix between two systems, so we want the page nomenclature to be as uniform as possible.

The status quo is Latin names except in the case of a few badly abused Protozoa, and then incongruent links to pages like cattle. Does anyone have any brilliant ideas on what should be done, before this becomes too messy? Thanks, JG

Authors include Josh Grosse and Andy Jewell

Links should be "[[Kingdom Animalia]]" rather than "Kingdom [[Animalia]]"

Strongly disagree. For one, it is annoying to always have to refer to the Kindom Animalia rather than the Animalia when you want to make a link. For two: some of the more prominent taxa, like Animalia or Cyprinidae, have precise rankings. But there are many whose position varies from scheme to scheme. I think it would be better to have a single page Rotifera rather than two pages, [Class Rotifera] and [Phylum Rotifera], one of whom merely sends to the other. And that's even a taxon with a well-defined position - what do you do for things like Bilateria?

And again, as below, I am going to suggest that for cases where no clear name has developed for the group, we just use common ones. It might be a bit confusing to have a mix of common and Latin names, but that's what the literature does when no clear consensus has emerged, and it's less confusing than listing each group on five different pages. Plus some groups don't even have Latin names: Stramenopiles, Opisthokonts, Rosette agents...

We need an easy english example by every entry. - When one exists, could be difficult for some things. :)

Andy, I just noticed that you're treating Linnaean taxonomy as something separate from phenetics, cladistics, and so forth. It's not supposed to be: most of the time, taxonomy gets changed to reflect evolution. For instance, the original Linnaean classification for Animalia had all invertebrates grouped into one class (phyla were invented later), and they were separated out when it became clear they weren't directly related.

I think what classifications we provide should probably reflect the best we have now, with separate pages for obsolete taxa explaining what happened to them. And while a complete classification for everything would be nice, I don't think we should do that. Especially for the Monera and Protista, where workers in the fields have actually stopped using ranks for the time being. There are too many tiny groups without relatives; noone wants to have independent phyla set up for each of Sticholonche, Hyperamoeba, Stephanopogon, etc.

For the same sort of reason, I'm not sure that it's a good idea to list all the supertaxa of each group. There are plenty of things out there where the lower taxonomy is stable but the higher is not. eg Tetras belongs to the Characidae, which is either in the suborder Characiformes of the order Cypriniformes, or in the order Characiformes. That difference can be explained on Characidae easily enough, but I'm not sure I'd want to repeat it for every genus.

In short: I don't think we can have tidy categories like you had hoped. Whenever we can, we should make a nice clean list. But when such a thing doesn't exist, we'll just have to explain that the system is still a mess, and then provide the reader with subgroups and speculated relationships between them rather than subtaxa. :(

I don't mean to be too discouraging, though, so please don't take this as such. The system works especially well for invertebrates, for whom if you are interested I think the standard source is Brusca & Brusca's The invertebrates (textbooks all have lame titles). It has a taxonomy for each phylum, usually down to order and sometimes further. For vertebrates, everything is a mess outside of the mammals and birds, and the higher taxa in plants are kind-of up in the air, so I'm not sure what one should do. But a good thing to compare to would be the Tree of Life.

I was just going to use Tree of Life as an example of why Linnaen and Cladistic are completely differnt things. Cladists don't much use KPCOFGS, and Linneans don't mind (and indeed can't escape) polyphyleticism. Also, for a Cladist tree I would suggest little more than a pointer to Tree of Life. Furthur, it seems "[[Kingdom Animalia]]" is Linnaen and "Kingdom [[Animalia]]" is Cladist.

Linnaean taxonomy and cladistics aren't contrasting systems. The former is simply a way of arranging organisms hierarchically, the latter is a methodology for elucidating evolutionary relationships. There are others, like phylogenetic systematics, disagreeing on how to determine these; but except phenetics they all support exclusively monophyletic taxa, and generally Linnaean frameworks are constructed accordingly. Cladistic taxa are ranked whenever convenient; it's just that for many things, the ranks are heavily variable and so ignored (as happens in other schemes too).

So, no, Linnaeans aren't happy with polyphyletic groups, and historically they have tended to be split up - eg Invertebrata or the removal of Fungi from Plantae. The ones we have left are mostly those too ubiquitous to drop easily, like Agnatha. Virtually everything has turned out to be polyphyletic among the Monera and Protista, which is why workers there tend not to use Linnaean taxonomy - not because they want to use a different system, but because not enough is known for a decent higher-level taxonomy to exist yet.

I think obsolete taxa are nice to mention, both as history and as a way to find out where groups got moved to, but I don't think they should be are primary way of sorting. For instance it should be said the plants used to include brown algae, but to treat their biology there is silly since they have little real in common. I guess maybe pages like [[Kingdom Animalia]] are a good way to handle such groups, but in that case we should probably be talking about the various ways the group has been used, rather than presenting it as the way living things are currently sorted. For instance Kingdom Plantae could say that in addition to the Plantae they used to include the Fungi and Algae.

Btw, as a minor note: genus is a third declension noun, so it's plural is actually genera. --- DOH!

Both genus and species names should always be italicized or de-italicized. As in, guppies belong to the species Lebistes reticulatus in the family Poecillidae, but goldfish belong to the species Carassius auratus in the family Cyprinidae.

Special concerns:

Prokaryotae - you say that this is a new form of Monera but I don't think that a majority has made the switch. There doesn't seem to be any reason to, and historically such names have tended to be ignored, at least (Protoctista, Chlorophycophyta, etc). A lot of workers tend to neglect the name altogether, since it seems to be polyphyletic. Any reason for choosing this form?

Protista - the classification of protista has been changing a lot recently, and I think most people have more or less abandoned higher level Linnaean stuff for the time being. Euglenids have variously been grouped as a phylum or class and referred to as the Euglenida, Euglenophyta, Euglenophyceae, etc. Some of the groups you mention have been dropped entirely, especially the amoeboid ones, due to heavy polyphyly, and I'd been leaving those off and grouping by rough grades (flagellates, amoeboids, algae, etc). I would love to hear if you have any good ideas on what to do, since the flat list seems wrong and what I was doing seems clunky.

Chordata - the current classification is awful and everybody hates it. The Agnatha, Osteichthyes, Amphibia, and Reptilia are all paraphyletic, and extinct forms are really hard to handle in them. They're standard, so we should mention them, but wikipedia doesn't have to organize itself on an obsolete and broken system if we don't want it to.

Misc terms - aren't plants normally grouped into divsions rather than phyla?

Removed from article pending resolution:

(This is incorrect or opinion)--Linnaean taxonomy requires creation of many more phyla than basic seven, and even then doesn't

provide full information about evolutionary relations between species. -- (This is incorrect, confusing taxonomy and classification, system and od) --To overcome this problems, cladistics was proposed as better way of classification.-- Enchanter 15:56 Jul 29, 2002 (PDT)

The species article included the additional taxonomic(?) categories of Subphylum, Suborder, Superfamily, Subfamily, and Subspecies. Do these belong under "Linnaean taxonomy", and thus should they be discussed here? Or do they fall under something else? --Ryguasu 08:08 Jan 11, 2003 (UTC)

What would be the proper name for a (currently non-existent) page on the magpie Genus Pica, that distinguishes it from pica (disorder) and pica, the disambiguation page (which also has pica, the font size)? Catherine 01:26 Apr 20, 2003 (UTC)

That's a curly one, Catherine. There is always Pica (bird) but that is a clumsy last resort. Maybe we could just use Magpie? Tannin
for the moment, I've changed the links on the taxonomy boxes of the various magpies to Pica (genus). I guess the alternative would be to put the genus at Pica with a disamb. block at the top pointing to the other two. Catherine

Contents

[edit] Metazoa

At this moment, both Animalia and Metazoa refers to animal. That is fine up to a point. The point being that current Taxonomic thinking does not use Animalia anymore but Metazoa. Now the question is, do we, when we have a latin name in a taxobox, the current name or some other name and how do we decide what name to use. And also, how we decide what "current" is.

One problem is with the prevalence of creationist thinking, the currenct renaming must be anathema to what they stand for. Do we say tough on you or do we say tough on science ?? GerardM 16:26, 28 Apr 2004 (UTC)

Except Metazoa doesn't seem to be more common. First, there is the problem that the two are not quite synonyms, since Metazoa may refer only to the higher animals, excluding the sponges and such. It was applied to the whole kingdom when protozoa were first removed, and still seems to be used that way sometimes. On the other hand, kingdom Metazoa is not so common. Certainly all the more-than-five-kingdom systems, which while not standard I would consider current enough, use Animalia. So I suspect this is a non-problem. I don't know where creationism comes into things. -- Josh
The issue is not whether it is common, the issue is what is correct. When current Taxonomy says Metazoa in stead of Animalia, ALL occurrences of Animalia have to be revised to the new knowledge. The issue is not whether they are synomyms and not what is more commonly known. Taxonomy is about the current state of the science.
The current science heavily relies on evolutionary thinking. Creationism denies this and as such the creationists may have a problem with modern taxonomy. GerardM 21:24, 28 Apr 2004 (UTC)

This is wrong. It is extremely important to note that there is no one correct system of taxonomy. Certainly it is supposed to reflect evolutionary relationships, but this allows for considerable variation in the rankand names of taxa, and biologists still even disagree as to whether paraphyletic groups are valid. Both Metazoa and Animalia are entirely correct; both appear in current literature, and have appeared in literature for many decades. Cladistics papers often seem to use Metazoa, but as I said, the most recent revision to the five-kingdom system I know of (six kingdoms by Cavalier-Smith) used Animalia. It's simply false that one or the other is correct. -- Josh

[edit] Time to consolidate

There is a bit of (now old) discussion over at Talk:Scientific classification about the redundancy of that page and this one. Although a number of knowledgeable people weighed in, the result in the end was that nothing was decided. I think it is time to act. This page is not even referred to in the Carolus Linnaeus article, which is where it really should go, being that most agreed the name "Linnaean taxonomy" was dated (or maybe that is my opinion? ;^)—although certainly of historic interest. I intend to start combining this effort (which in some ways, is the better discussion) with both Scientific classification and Carolus Linnaeus articles. - Marshman 03:47, 16 Jul 2004 (UTC)

I agree that "Linnaean taxonomy" isn't a good term. I haven't had a look at what other articles touch on related subjects so can't contribute much except to say, go for it...
I'm completely baffled by the term "Scientific classification," which I don't like at all. The main terms should, I think, be "Carolus Linnaeus," "Taxonomy," and "Systematics," though what should go where and how they should cross-reference will take some doing. It's possible that there should be an individual article on the various codes of nomenclature, but again it would require some kind of synthetic title. Zoological Code of Nomenclature redirecting to "Codes of Nomenclature" or "Codes of Biological Nomenclature..." ugh... I don't like it. Just-plain "classification" could/should disambiguate or redirect to "taxonomy," if it doesn't already.
Haven't seen whether this is already somewhere else but there needs to be an explanation of why the binomen is not and should not be referred to as "the Latin name," and an explanation of how extremely practical this is and that it isn't just jargon invented to baffle the laymen... you know, a daddy-long-legs refers to two different things in the U.S. and some hole 'nother thing in the U.K....
Somewhere, the trivia point needs to be made that Linnaeus is the only human being customarily referred to by a single initial. Of course there are always arguments about whether the SI abbreviations of units named for scientists count... I'd maintain that N stands for newton, the unit, not Sir Isaac... Dpbsmith 10:49, 16 Jul 2004 (UTC)
All good points. The "Scientific Classification" needs considerable thought, as I see two concepts being promoted here. Scientific classification is what biologists call systematics. But the term certainly has much broader connotations. As for those "other" articles, I think they can follow from the more general text as someone steps up to prepare them, so my consolidation may do no more than get everyone to the same "basic" page instead of the two poorly interlinked ones we have now.
The binomial is explained in at least one place. Not seen it called the "latin name" yet here, but that is commonly done. I think the "scientific name" is what I see more often. I like the trivia point. There probably is a place for it at Carolus Linnaeus. - Marshman 17:12, 16 Jul 2004 (UTC)

I am quite unhappy with having a page "Linnaean taxonomy"

A great many topics are involved:

  • Linnaeus: except for brief summaries, the material on Linnaeus should go to an entry "Linnaeus"
  • the phylogenetic approach, in general (Darwin, non-cladistic methods, etc). I am not sure if there is an entry for that yet?
  • cladistics: is in cladistics and should stay there
  • classification in the abstract: a ranked hierarchy (kingdom, class, order, family, etc). This could go to "scientific classification" which appears the phrase of long standing (like it or not)
  • classification for the various groups: animals, bacteria, plants, viruses. These deserve separate entries
  • nomenclature in the abstract, is now mostly in "binomial nomenclature"
  • nomenclature for the various groups. I have been trying to add to these

This leaves "Linnaean taxonomy". As this is a recent phrase (of less than ten years standing?) for what is described under "scientific classification" the present entry could be dismantled (carefully, so as not to lose anything). This could be replaced by a description of usage of the phrase "Linnaean taxonomy" which is mostly zoological, by proponents of cladistics. Brya 08:09, 4 October 2005 (UTC)

I'm pretty sure it is a lot more than ten years old, but your point is well taken. There are too many articles covering this topic. I started to consolidate at one point, but got distracted and never returned to the task. "Linnaean taxonomy" probably need not exist as an article. - Marshman 04:22, 8 December 2005 (UTC)

[edit] linking and rationalizing

I am not consolidating the pages, but I am making them self consistent and adding the appropriate links. There's a few m ore of these preliminaries to be done. I've added the page for the International Committee on Systematics of Prokaryotes in order to be consistent with the others, and will do the one for the virus codes tomorrow. The alternative would be combiningthe codes, and the organizations, but this won't fit into whatevery categories there are. It can always be done later;

As for "Scientific Classification," I propose changing the title of that page to "Biological Classification." There are other scientific classifications, but I'll adjust the disambiguation page for classification to leave room for them, though I do not intend to write them.

The next step will be considering the overlap of the pages for Linnean Taxonomy and Biological Classification. I think there is a point in keeping the historical material about the pre-evolutionary classification methods separate. It looks to me like the best first step would be to interchange the contents. Not a joke, I'd like comment. DGG 04:29, 16 September 2006 (UTC)

[edit] Superregnum?

The wiki taxonomy site starts with "Superregnum" and "regnum", where "regnum" is the animal, plant, fungus kingdom, etc. But the wiki taxonomy entry at wikipedia makes no mention of Superregnum. Can someone fix this? -s/he means wikispecies

Fixed- I added domain (=superregnum), with a disclaimer, to this entry as I did to biological classification. The omission was glaring. This is one of the only problems with wikipedia- since people write based on their background knowledge, past accepted fact is perpetuated. I'll now note in another edit that domain and superregnum are equivalent, and maybe add a wikispecies in the refs. if there's not one there already.

[edit] Anon recent additions to the "example" classification

In some cases, the additions are incorrect or poorly stated or they are not necessarily unique or defining of the taxon, even if true for humans. I will try and correct rather than revert; others may wish to weigh in? - Marshman 19:43, 11 January 2006 (UTC)

[edit] Vandalized mnemonic

The mnemonic has been vandalized but I'm not correcting it as I'm not familiar with the mnemonic and I'm not certain that the original text was correct in the first place! MrDarwin 16:46, 25 January 2006 (UTC)

  • For what it's worth, the one I learned was "Kings play cards on fairly good soft velvet." I believe there's a plethora of them in the article on Mnemonic. Maybe we should just link there. Dpbsmith (talk) 14:11, 26 January 2006 (UTC)

[edit] "cling to"

" . . . some botanists still cling to this rank . . ." Isn't that a bit strong? How about, ". . . some botanists still prefer this rank . . ." ?


[edit] Monophyly vs Non-polyphyly

The following statement from the article is confusing in that it implies that all Linnaean taxa can be made monophyletic: "It then became generally understood that classifications ought to reflect the phylogeny of organisms, where each taxon should originate from a single ancestral form. Such taxa are designated as being monophyletic. In modern systems it is generally encouraged that taxa should be strictly monophyletic, reflecting the way new species arise."

It isn't possible to make all Linnaean taxa "strictly monophyletic". By establishing a particular taxon in such a way as to be monophyletic, we thereby establish all ancestral taxa of equal and lower rank as paraphyletic. For instance if we establish the order Primates as monophyletic, then the order, family, genus and species of the Primates' immediate ancestor must be paraphyletic. Similarly, every speciation event creates a new paraphyletic taxon - that of the parent species. (See Brummitt 2002 [1] for more discussion).

Accordingly, I'd recommend changing the statement to something along the lines of: "It then became generally understood that classifications ought to reflect the phylogeny of organisms, by grouping each taxon so at to include the common ancestor of the group's members (and thus to avoid paraphyly). Such taxa may be either monophyletic (including all descendants) such as genus Homo, or paraphyletic (excluding some descendants), such as genus Australopithecus."

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