Talk:Kingdom (biology)

More than 5 kingdoms

I was wondering what everyones ideas are about higher than 5 kingdom classification systems. I was taught the 5 kingdom system as an undergrad, but this system lumps archaebacteria and eubacteria into Monera which I really don't care for. Another system that looked interesting at first but then never really caught on is the 8 kingdom system (archived 2003-03-29) which splits Protista into three separate kingdoms along with the eu/archae-bacteria split. At the very least I think it would be useful to split Monera since this would make our system compatible with the 3 domain classification system (otherwise Monera has two domains). --maveric149

I think splitting Monera is a great idea. We could either call the two pieces kingdoms, or simply list domains in place of kingdoms for the prokaryotes. Note animal currently identifies that kingdom as a subgroup of the eukaryote domain, so we would be being reasonably consistent, although I think we may want to skip listing eukaryote on phyla and lower ranked groups.

I agree that we should get rid of "Monera", and replace it with links to two different kingdoms: True Bacteria and Archaea. However, I am not comfortable editing Wikipedia tables, and will leave this change to others. As for the idea of splittin up protista, it is now failt well accepted that the protista contain not just 3, but many kingdoms. In all seriousness, it seems that the term "protista" can best be defined as "All the other kingdoms that don't fall into Bactera, Archaea, Plantae, Animalia and Fungi". RK

I think you are right in that we should move from the five kingdom system to a six kingdom one and leave all the "leftover" kingdoms lumped in protista. The table color for Archaea could simply be a darker grey. --mav

I tend to disagree. I was taught 5 systems at school, then moved to a three system. These are the systems used and known in the "real" world. I don't think it is Wikipedia role to decide to start a new 6 system just because the actual system is not satisfying. I think it would be very confusing to visitors, as it is not what is currently most well-known. Anthere

It is well known. I was also taught the 5 kingdom system which is a huge improvement over the 2 or 3 kingdom ones. However, there is a large flaw in the five Kingdom system in that it lumps Bacteria in with Archea. This wouldn't be so bad if Bacteria and Archea were merely two different kingdoms in the same domain but they are two different domains. Therefore in order to make the most widely used system (the 5 Kingdom one) work with the newest research which states there are 3 domains we must divide Monera in two. My feeling is that biology is moving in this direction already. My undergrad micro professors always taught that Monera is outdated and that we should use Bacteria and Archea. We needn't keep Wikipedia stuck in the 1980s in this regard. --mav 18:40 Feb 15, 2003 (UTC)

Then, create a new page to present your new system, but don't remove the one that is explaining the system that is the most widely known. As a microbiologist myself, I have always rather strongly separated bacteria from archaea (we don't use monera). I have also heard enough times that what we are doing here is not "proposing" new theories (or even forcing new theories). Your "feeling" that biology is moving in that direction doesnot seem enough to me to make a widely known system disappear to replace it with a just emerging system. If we do so, it should presented as what it is, a new system emerging, proposed by such and such guy.

And btw, I am a bit confused between your kingdoms and domains, because we use a common word for them, "règnes"; in any case, I think the 3 "règnes" system is a *huge* improvement over the 5 "règnes" one.

Be careful about splitting up Protista. The Chromista or Stramenopila are well-established and I have seen them ranked as a kingdom in a few places, but the Archeozoa are likely polyphyletic and I don't expect them to gain much currency. Also, you occasionally see a kingdom Alveolata or kingdom Euglenozoa, and maybe a few other groups. However, the Protista left behind is going to be a paraphyletic junk-basket unless you create an insane amount of kingdoms, so the sectioning really only helps to emphasize the monophyly of the new group in question. I wouldn't mind, but most people seem not to bother. --Josh Grosse

The five kingdom system is finally being replaced by 6 kingdom systems, even in high school textbooks. I have a new High School Biology texts which has a system that seems to address everyone's concerns, both about accuracy and about ease of use. The new Prentice Hall textbook has a diagram which shows both the 3-domain and 6-kingdom system together. I am not up on using tables in Wikipedia format, but it looks something like this: The three domain are presented in a larger font, and underneath each one finds the kingdoms. RK

This is not a good way to word it, It has not been "finally replaced." There is no standard, and our current understanding is nmost unlikelyt to be finally correct. The best way of presenting it is a tree diagram, but I, too, do not know how to do that here.

Bacteria ----- Archaea ----- Eukarya (Domains)

Bacteria ----- Archaea ----- Animalia, Plantae, Fungi, Protista

I have no trouble to working with another system. But removing everything of the old system is just a revisionnism I think abusive. Please, do not make utterly disappear the old system on behalf it is not considered the "right" one now. At least, preserve it somewhere. It is not because some think a classification is the "right" one *now* that the old way taught a couple of years ago is "wrong" and should be discarded.

I also agree that we should not get rid of references to the 5-kingdom system and replace them with the 3-domain system. Rather, I am saying that on this page we should have both systems, as shown above. I am only saying that we need to tweak it a little by using 6-kingdoms instead of 5, because Archaea and Bacteria are just so vastly differet that we need to note this at the outset. In fact, why not have a brief history of how classifications evolved? RK

• Plant - Animal

• Plant - Animal - Fungi

• Microorganisms - Plant - Animal - Fungi

• Bacteria - Protista - Plant - Animal - Fungi

• Bacteria - Archaea - Protista - Plant - Animal - Fungi

I agree with RK. This page is not necessarily about the Five Kingdom system but it is about the biological classification known as Kingdoms (we can and should have a separate page on each Kingdom system eventually). It would be negligent of us if we hid the glaring fact that Monera is a preposterous excuse for a Kingdom (even more so than Protista - which can at least be thought of as a super-Kingdom). But on this page we should, as RK states, show how the classifications evolved. But the table and the colors dictate the organizational schema that is going to be used for WikiProject Tree of Life so for that project we need to standardize on a system that makes sense for both domains of prokaryotes and doesn't totally get rid of the most widely-used system (the Five Kingdoms). --mav

I added some discussion of the different systems. I don't remember the exact course of their development, so that would have to be added in later. Still, does what's up satisfy everyone? -- Josh Grosse

Yup! I clearly was out of my mind since I didnot understand that was what Mav intended to do from the very beginning, keeping history rather than removing the 5 kingdom for the benefit of the 6 kingdom. I changed our link since the object of the page changed. Thanks Josh.

Not bad, not bad at all. I'll be making some mods in order to solve the WikiProject Tree of Life issue but I really like what you have started. --mav

Revisiting this. The very few prokaryotic pages that have taxoboxes list domain Bacteria with no associated kingdom, which seems to be preferred to listing kingdom Bacteria with no domain (listing both is redundant). As such, the 6-kingdom system listed on this page is not really being used here, and so I don't think it deserves the prominence it is being given on this page. That is, while it should be definitely mentioned in the text, I don't think we need to have a third table listing the same groups as the first two. So I am removing the third list (which is visually distracting anyways), while encouraging anyone who felt it was really important to reverse the edit.

Here's another thought. We could have a single table accompanying the text discussing the different systems. This might make editing a little harder, but it isn't that simple to begin with, and should make reading somewhat easier. Perhaps something like this:

Haeckel (1894)	Whittacker (1969)	Woese (1990)	Six kingdoms
Protista	Monera	Bacteria	Bacteria
		Archaea	Archaea
	Protista	Eukarya	Protista
Plantae	Fungi		Fungi
	Plantae		Plantae
Animalia	Animalia		Animalia

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I'm going to cut and paste here a note I posted to Josh Grosse when I saw he'd made "Protoctista" into a redirect for another classification (I can't remember at the moment whether it was "protist" or "protozoa"). I assume it's pertinent to the discussion here, although I confess I haven't read it:

I noticed you made "Protoctista" a redirect and left no mention of the classification anywhere on Wikipedia. Even if the term represents a classification system you don't like, censorship is heavy handed, don't you think? Meanwhile, as far as not liking it, while I'm not up on taxonomy or the discussions about it on wiki, I see that the authors of several encyclopedias and reference books have been confident enough to represent "protozoa" as an outmoded term and "protoctista" as current. According to the xrefer Website, the 2000 edition of the Oxford University Dictionary of Biology defines "protozoa" this way

"A group of unicellular or acellular, usually microscopic, organisms now classified in various phyla of the kingdom Protoctista (see Apicomplexa; Ciliophora; Rhizopoda; Zoomastigota). They were formerly regarded either as a phylum of simple animals or as members of the kingdom Protista."

So why don't you like the terms and on what grounds would you remove it all together? 168...

I have nothing against the term, and am certainly not trying to censor it. Simply put, the Protoctista and Protista are almost entirely synonymous and are both currently used. The latter is somewhat more common then the former, which is why it's the term we've been using here. I've added mention of it to Protista so it will turn up in searches. Further explanation of the two terms would best be part of a discussion of different classification systems, which nobody has decided to research and write yet. That's all.

The formal taxon Protozoa is for the most part considered obsolete, but people still use the term protozoa as a descriptive term, without implying anything about the relationships of the groups in question. That's the way it's being used here, as a convenient way of organizing the many different groups included in the Protista. I suppose I could try and curtail it somewhat, if that's what we wanted to do. It should be noted that the Protozoa do reappear in some of the more recent classification systems, where most of the algal and fungus-like forms have been segregated into new groups like the Chromista, but this doesn't seem to have much support yet.

Thanks, Josh

I really like the single table above. --mav

Yeah, here is another vote for the single table. Should we also keep every previous table in the article? One part of the article can trace the history of kingdom classification with the current individual tables, and this multi-table can appear at the end as a way to compare them all. Hmmm; that might be too confusing for many readers. Maybe we can keep all the text, and just use this table? What do others think? RK

My vote is to just use the summary table. We don't need to give the reader the same information three times. -- Josh

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Hm. From my research it seems that Woese first promoted a 6-kingdom system but later adopted the 3-domain concept. Can this be confirmed? If true we need to tweak the table so that the 6-kingdom system comes before the 3-domain system (I don't know how to do this). We also need to tweak the text. Here is my evidence:

According to Campbell 5th Edition, page 499 (ISBN 0-80531957-3), which reads; "Archeabacteria and eubacteria diverged so early in the history of life that many researchers, led by Carl Woese of the University of Illinois, first proposed a six-kingdom system: two prokaryotic kingdoms along with the four eukaryotic kingdoms." The text then introduces the three domain system but doesn't say who led that charge (although we already know it was the same person).

--mav

Done. Wonder if it's worth putting any other systems in the table. --Josh

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However, the most recent such classification, the three-domain system, institutes a level of classification above the kingdom, called the domain.

The introduction of ranks above kingdom is not something peculiar to the three-domain system, and I don't see any good reason to single it out like this. It's already discussed as part of the historical sequence.

Under the three-domain system of classification, the domain Eukarya is typically split into a large number of kingdoms.

Sometimes, but often they are simply left as four or five kingdoms, and I'm not convinced that's not the more typical approach. The introduction of additional eukaryotic kingdoms is already discussed, and it should be obvious that they'd go in the Eukarya.

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On Talk:Domesticated outsider taxa i pose a queston abt my nonce term "outsider taxa", which also relates to Domestication --Jerzy 09:36, 2003 Oct 27 (UTC)