Talk:Arthropod

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November 10, 2008 Good article nominee Listed
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Old encyclopedia articles on arthropoda[edit]

I submit a list of Wikisource articles from old encyclopedias for your consideration for use in the "External links" section (N.B. This list has been augmented since the comment was initially put here.):

I initially just posted a link to the Collier's article in the "External links" section using a poster format:

This addition was reverted manually with the comment "Rv. Provides no worthwhile information - very brief and largely out of date." The 1921 Collier's article is indeed very brief, and out of date. The worthwhile information I think it provides is a snapshot of how this phylum used to be viewed.

I then posted a list of three articles, similar to the list above except it didn't include the NIE article. It was again reverted, this time using undo, with the same comment, "Rv. Provides no worthwhile information - very brief and largely out of date." The 1920 Americana article certainly is briefer than the Wikipedia article, but I would not describe it as very brief. In addition it has a very interesting section on "History and Present Classification" which is a topic the Wikipedia article does not touch on, and I think such an exposition would improve it. Though obviously the 1920 Americana information on "History and Present Classification" is too dated to stand alone, it might fit in as a part of a more complete historical section.

The articles do come with links to disclaimers which explain the information may be out of date. Rather obvious I think, but a reminder helps I suppose. Perhaps this addition would be appropriate with suitable comments on exactly what is out of date? I have shown how to append a comment on one article above. I would not attempt to do it myself. But just as they stand, I think a spectrum of old views of the phylum is useful for people who are interested in how science has developed. There are people interested in the history of science.

Bob Burkhardt (talk) 18:07, 6 January 2011 (UTC)

The information is indeed interesting to a student of the history of classification, but not to a general reader interested in arthropods. Without any explicit indication that the information is of purely historical interest, it would be misleading to include any of these links. Wikipedia policy on external links is only to include links to material that is reliable but which we couldn't reasonably include. Outdated encyclopaedias contain material that is either out of date or which could be included in the article itself (and indeed probably should be). For example, the Collier's text runs: "ARTHROPODA, a subdivision of the annulosa, or articulata, containing the classes belonging to that sub-kingdom which are of the highest organization. The body is very distinctly divided into rings or segments, sometimes, as in the myriapoda (centipedes and millepedes), mere repetitions of each other, but more frequently with some of them differentiated for special ends. In general, the head, thorax, and abdomen are distinct. Under the subdivision arthropoda are ranked in an ascending series the classes miriapoda, crustacea, arachnida, and insecta." Neither "Annulosa" nor "Articulata" are used today, so that clause is unusable. The concept of the "highest" level of organisation is teleological thinking, which is no longer accepted by mainstream evolutionary biology. That also applies to the "ascending series" of four classes (which was inaccurate even in 1920, trilobites having been known for many decades). The remaining information is a very bland description of myriapods as having repeating segmentation, and a general division into three tagmata. All of that is already in the article in considerably more detail than provided by the link. I have only tackled the shortest of the linked texts here, but I have examined them all, and similar arguments apply in all cases. The information they provide is either already included or, from a modern standpoint, wrong. They may be useful links if ever we had an article on "historical classification of arthropods" or something similar, but I do not see that they are useful supplements to this article. --Stemonitis (talk) 19:51, 6 January 2011 (UTC)
A discussion of the history of a concept seems a natural component of an article on it. Of course if it gets too involved, there should be a main article on the subject. And indeed this Wikipedia article has a section remarking on how some time ago (late 1950's as opposed to 1920 Americana's citation of 1893, 1894, 1898) classifier's thought it Arthropoda might be polyphyletic. It is apparently short-sighted and a perusal of the Americana article would probably lead to its improvement. The Americana article in addition notes who originally formulated the category. I don't feel I have the expertise to dovetail the Americana information into what is already there. Your remarks, suitably referenced, would be an interesting addition to the historical section. Even given this was done, I think the links to the other dated encyclopedia articles is useful just for the different points of view and treatments of the subject in different encyclopedias. So I think there is something to learn, especially from the Americana article, for editors of this article. Bob Burkhardt (talk) 18:00, 10 January 2011 (UTC)
In that case, we disagree. Information so out of date that it counts as misinformation has no place in an article, or being linked to. You state that the "Americana article in addition notes who originally formulated the category", which is true, but Encyclopedia Americana is plain wrong; as our article and almost all other sources state, the taxon was erected by Pierre André Latreille in 1829, and not Siebold (or "von Siebold & Stannius" as it should probably be), not that the Principle of Priority applies at such ranks (cf. ICZN). The whole source is utterly unreliable, partly because of its age, and partly because of human error. There is nothing for editors of this article to learn from the Encyclopedia Americana article. --Stemonitis (talk) 18:27, 10 January 2011 (UTC)
Well then someone should fix the Wikipedia articles on this then. The article on Pierre André Latreille gives him no credit for introducing the taxon (not specifically anyway), and the article on Karl Theodor Ernst von Siebold gives him credit for introducing it, with no sign of the 1920 Americana anywhere. But both these articles look like they need some work. Inventorying my ancient sources, I see neither the 1920 Americana article on Siebold nor the 1911 Encyclopædia Britannica article on Siebold make the claim. The 1905 NIE article on Siebold does, and notes he (not they) introduced it in the Stannius and Siebold book. Wouldn't a detail like that be an interesting contribution to this article, and give more credence to Latreille's claim, instead of a little Latreille 1829 in the infobox, and perhaps such a detail would be more appropriate here than in the Latreille article. I wouldn't try to write a history based on the ancient encyclopaedia articles, but at least they give an inkling of what was going on between 1829 and the late 1950's. Notice the article on Gravitation is not an article on the history of gravitation, but it does have a substantial section on the history gives at least an outline of significant contributions over time. Seeing how a concept develops contributes to someone's understanding. That is lacking in this article. Developing this taxon didn't all happen in 1829 and after the late 1950's, and all that is said about 1829 is the date. The historical aspect is something any mature article on an idea should deal with in a complete way. Bob Burkhardt (talk) 02:08, 20 January 2011 (UTC)
Actually, nomenclature is a little more complicated than that, and it turns out that Latreille's contribution may not be as great as you think. The date of 1829 is not when the concept arose, or when the taxon was first formalised; instead, it is when the name "Arthropoda" was first validly published. The concept had been around a long time (I suspect since at least Pliny the Elder), and was the taxon referred to by Linnaeus as "Insecta". A discussion of the history of the concept would be interesting, but would ideally be based on up-to-date sources. In this case, modern sources should be available, so I do not see that the antiquated encyclopaedias you have supplied would be terribly useful. You are right that our current article on Pierre André Latreille is poor. It has very few references and does not properly establish his significance. If you wanted to spend time improving that article, it would be much appreciated. --Stemonitis (talk) 07:29, 20 January 2011 (UTC)
1911 Britannica (11th edition) gives Siebold and Stannius credit for coining the name "Arthropoda." The 9th edition (1888?) credits Latreille with formulating a category very close to the 1888 conception of Arthropoda, but says he gave it a different name. It is curious how that information got abandoned in 1911. These are both very long and involved articles, much like this Wikipedia article, all three of which I need to study more closely. None go back to Pliny the Elder and Linnaeus, but of course I would be willing to see them included as well. Another benefit from a historical examination would be a sequential look and what got included and excluded and would give more insight into the philosophy of the category and who contributed to its development and how they contributed. I do agree with you on the benefit of consulting modern sources, but, on natural history and many other topics, I think older sources can have much to contribute, even from an "ideal" point of view. All have to be used critically of course. I will consider working on Latreille, and also doing something with Arthropod on this issue if no one more expert takes up the gauntlet. If there is a specific work of Latreille that can be cited, that would help things; the "1829 Latreille" looks more and more cryptic to me. Bob Burkhardt (talk) 23:15, 24 January 2011 (UTC)
Again, such information might be interesting, but is surely outside the scope of this article, and even if we wanted to discuss how concepts of authorship varied over time, we could not cite those old works without it being original research. You and I might be able to see how usage changed, but until someone else publishes an article on "The changing authorship of the phylum Arthropoda", for instance, we can't talk about it. We would need to cite an up-to-date source which states that early encyclopaedias credited the taxon to Siebold and Stannius or whoever. The sources you favour would then be valuable "Further reading", but cannot be admissible as references. --Stemonitis (talk) 07:42, 25 January 2011 (UTC)

Ligaments are not muscles.[edit]

In the third paragraph, as part of the "Internal Organs" section, is says this:

"Elastic ligaments, or small muscles, connect the heart to the body wall and expand sections that are not being squeezed by the heart muscle."

The way this is written, it seems as though the author is defining ligaments as another word for "small muscles." I do not know much about arthropods at all, but I do know that ligaments are not a muscle. So I can only assume the author meant to say "Either elastic ligaments, or small muscles connect the heart....."

Nihilianth (talk) 15:22, 16 February 2011 (UTC)

You're right, thanks. I edited to "either by elastic ligaments or by small muscles, in either case connecting the heart to the body wall." --Philcha (talk) 16:32, 16 February 2011 (UTC)

Yeah, no problem. Just thought it needed to be clarified. :) Nihilianth (talk) 06:17, 17 February 2011 (UTC)

Diania cactiformis[edit]

There is a claim of a new possible ancestor to arthropods: Diania cactiformis. It would be interesting if someone with expertise in the field can take a look to the publication and add it if it has enough merit at this point. —Preceding unsigned comment added by 200.112.67.227 (talk) 17:39, 24 February 2011 (UTC)

We already have an article, at Diania. The classification there places it outside the Arthropoda, but it may still be worthy of a mention. We might need to leave time to see what the scientific community makes of it first. --Stemonitis (talk) 17:49, 24 February 2011 (UTC)

Misleading phylogenetic tree?[edit]

The Classification section contains a phylogenetic tree which is, I think, somewhat misleading in the context of the paragraph beginning "The phylogeny of the major extant arthropod groups..." It uses a tree from Hassanin (2006), rather than one of the other five references given in the paragraph. There are two issues with this:

  1. Splitting Collembola from Insecta seems a particular feature of this source and is not supported generally.
  2. Hassanin explicitly says "Basal relationships between Pancrustacean lineages are not robust, and the question of Hexapod monophyly or polyphyly cannot be answered with the available mitochondrial sequences." So his tree should not be used to illustrate non-monophyly in Hexapoda.

One of the latest papers is: von Reumont, Bjoern M & et al. (2011), Pancrustacean phylogeny in the light of new phylogenomic data: support for Remipedia as the possible sister group of Hexapoda, Molecular Biology and Evolution, doi:10.1093/molbev/msr270 . This broadly supports the other sources in the Classification section, showing a monophyletic Hexapoda nested inside a paraphyletic "traditional Crustacea".

The other question is why the phylogeny material is in this section anyway, and not in the previous section. Peter coxhead (talk) 12:00, 18 December 2011 (UTC)

Digestion[edit]

Perhaps a paragraph on the structure of the gut and digestive glands would be helpful? Danger! High voltage! 01:57, 11 July 2012 (UTC)

Single ancestor debate[edit]

Most of the comments above have at their roots the "single ancestor of all arthropods" debate. I'm no longer current in this field, but the article needs to give high prominence to the fact that the debate exists, which the article as it stands does not. (The casual reader would be forgiven for thinking that the orthodox view was that there was a common ancestor, and there was no debate.) My advice would be that there needs to be a 'flag' up front in the introduction that the term 'arthropod' might refer to a bunch of creatures that are not related, and that there is not, as far as I know, a definitive resolution.

Unfortunately I've changed disciplines and am no longer "current" in this field, so I must leave it to others to resolve this issue. --Wally Tharg (talk) 09:30, 12 August 2012 (UTC)

Everything that I have read says that the debate is considered settled and polyphyly of arthropods is no longer taken seriously by experts in the field. "a unique origin of the euarthropods is well established" [1], "Monophyly of Arthropoda is emphatically supported from both morphological and molecular perspectives" [2], "monophyly of (Eu)arthropoda is well established" [3], "the Uniramia hypothesis is now generally considered obsolete" [4], "A decade or so ago there were even serious arguments over the single versus multiple origins of arthropodization, and therefore over the monophyly versus polyphyly of euarthropods (Fryer 1997). Molecular analyses have emphatically supported the monophyly of euarthropods and a unique origin of their cuticularized body and jointed appendages and in the past years, the attention has been focused more on the relationships between these four groups." [5]. Eluchil404 (talk) 10:21, 12 August 2012 (UTC)
Thanks for a detailed and definitive answer to my query. Having looked at the article again I see that there is a sentence or two about it ... but it makes no reference to the articles that you cite above. I don't want to wade in and add these references for the reason stated above. Might I suggest that this is done? I'm sure that I wasn't the only person coming to this page with this query. Even better, how about a sub-section on the polyphyly debate, saying that it's now wrapped up using molecular evidence (I was last in the field 30 years ago ...), i.e. giving it more prominence. As it stands there's now a far better explanation in the talk page than in the article itself. --Wally Tharg (talk) 15:13, 12 August 2012 (UTC)

Hexapoda: Camptophylla, Incertae sedis?[edit]

The taxobox on Arthropoda has a somewhat ambiguous formatting below Subphylum Hexapoda: Incertae sedis appears a rank of its own: does it refer to Camptophyllia? If so, it might be more clear to combine the 2 on a single line, otherwise denote i.s., or clearly indent Camptophyllia beneath Incertae sedis. Animalparty (talk) 21:23, 26 October 2013 (UTC)

Agree It is odd to have an expression meaning "off uncertain affiliation" in a listing like this. It is meant to replace the name of taxonomic unit, where this is unclear or where views differ. But without a subtaxon, it is utterly without meaning.-Dwergenpaartje (talk) 08:45, 22 November 2013 (UTC)
I think it was meant to be the way I have made it now, i.e. "incertae sedis" refers to subphylum. Peter coxhead (talk) 19:56, 25 November 2013 (UTC)
Much better, although I think it actually needs to say what you have written down here, so Subphylum incertae sedis. --Dwergenpaartje (talk) 19:59, 26 November 2013 (UTC)

Rapidly growing industry and international trade?[edit]

In the section: Interaction with humans the following statement is made…”which is the basis of a rapidly growing industry and international trade.”[1] The website cited contains data only up to 2001 and most of the data was only recorded in the 1990’s. Which means that we really don’t know if honey production is a rapidly growing industry. I propose this statement be deleted or more up-to-date references is provided.

bpage (talk) 12:07, 26 July 2014 (UTC)

  1. ^ Apiservices — International honey market — World honey production, imports & exports, retrieved October 3, 2008