Linnaean taxonomy/Talk

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

• Some grops 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

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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.

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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?