From Citizendium, the Citizens' Compendium
Jump to: navigation, search
This article is developed but not approved.
Main Article
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
Gallery [?]
To learn how to fill out this checklist, please see CZ:The Article Checklist. To update this checklist edit the metadata template.
 Definition A multicellular organism that feeds on other organisms, and is distinguished from plants, fungi, and unicellular organisms. [d] [e]

Thanks for the effort, but--ouch, not a good first sentence. Please see Biology for a model of readability, and Article Mechanics for some relevant comments. --Larry Sanger 14:31, 26 March 2007 (CDT)

On phylogeny: help!

I've been writing this article for the past few days, but I've hit a snag: animal phylogeny. I've been referring to my introductory biology textbook for most of my information, but with some research in journals I've found that the theory that my book uses is still controversial and muddled sometimes, especially in Bilateria. The most fundamental argument is over the pitfalls of the new data from molecular phylogeny, etc. used to rearrange everything. Other smaller examples include where Rotifera, Acoelomorpha, etc. are placed among Deuterostomia, Ecdysozoa, and Lophotrochozoa.

I'm now too afraid to type any more on the phylogeny section now that I know that my book is contradicted by other recent reports; I don't know if I've written anything that's false. (My book, the Freeman text cited in the article, is from last year, so it's recent. I don't know enough to gauge its objectivity, however.) I ask for help from everyone who knows enough about animal taxonomy. I welcome suggestions here, but editing the article itself is great too! Joshua Choi 23:21, 30 March 2009 (UTC)

Don't forget that "Phylogeny recapitulates ontogeny", or is it vice versa? See my novel, hehe.... Hayford Peirce 00:02, 31 March 2009 (UTC)
Yes, but I'm afraid my muddled mind can't understand yet how I may apply ontogeny to the phylogeny section. Most of all, it seems like I'm groping around with this article on my own, and I am in no way a professional biologist, so I don't know well what's going on right now. I guess I can just plod ahead with my book's phylogeny, noting in the text that the accepted model is still controversial and being fleshed out. Be bold, I guess.
But if any experts have more advice, I'd love it!
PS. Wow, you're a novelist? That's awesome! Joshua Choi 04:27, 31 March 2009 (UTC)
In general, an excellent clear job. One of the best articles here.
I will take a look at this-- I do follow the subject, though from a distance. So far, what you say seems to be correct. There probably is a little more to say.: the separation of the proteostomes and deuterostomes in particular goes back some time now, and was originally based upon descriptive embryological evidence, first systematized by Libby Hyman in the 1950s. the organization of the larvae of the two groups are radically different. I will look for a good diagram. The sensational part of it to me is that her theory turned out to be firmly supported by molecular evidence. It would be good to explain what the molecular evidence is actually based on. This is the way to get the ontology into the discussion. (That ontogeny recapitulates phylogeny is a gross oversimplification of the 19th century--it applies only to embryonic forms--I think its a phrase to be avoided. I would add a further discussion of the way the development of all the animals is basically the same: the structure of the genes for segmentation and differentiation is parallel to the extent of definitively proving common origin. In this connection, some discussion of the origin of sex in the different group would also be appropriate.
I see some other omissions--motility needs to be discussed, and also parasitism, including the concept of the degeneration of function in parasites. The structure of the nervous system should be mentioned as well. Some idea of the paleontological basis of the evolution also needs to be discussed. And there has to be some mention of the relationship of all animals to other organisms--in particular the relationship with the fungi, which have a common ancestor with animals, not with plants.

I see only one outright error: starfish only appear to be radially symmetrical. If i remember the lectures correctly, they're bilateral, and the earliest embryonic forms one of the arms divides into two, giving the appearance of radial symmetry in the adult. .

An excellent source for much of this material is Wikipedia. At the moment the licenses are not 2-way compatible, but they will be in a few months when Wikipedia changes to CC by sa 3.0 dual licensing. Even now, they are compatible one way, from WP to Cz . I will copy over and improve some of the better parts of the key articles. Many of them have been done by very well informed amateurs, and checked by experts DavidGoodman 06:49, 4 May 2009 (UTC)

On the starfish: I learned that larva starfish are bilateral, but adult starfish are considered radial. (I do note this in the text nearby.) I do not know, however, if their internal anatomy is still bilaterally symmetrical. The reason why I chose a picture of a starfish to represent the radial animals is that I could not find a good top-down picture of any medusas or jellyfish on Flickr.
I'll go add stuff for omissions you've pointed out in a bit. Thanks for all the suggestions. Joshua Choi 19:35, 4 May 2009 (UTC)


Beautifully written, outstanding job. I've seeded the bibliography with a few recent review articles that seem to be good starting points to current trends in academic research.

I'm more than happy to support approval of this. I'm not an expert in phylogeny by any means, and that is an area that is changing very rapidly. Maybe Chris Day can comment?Gareth Leng 08:59, 4 May 2009 (UTC)

I agree with Gareth on the overall quality of the article. I had planned to write a bit about fossilization anyway, and so I might as well start by adding something about the fossil record here. Will do so later this week. Does anyone have a better-quality version of Image:Various vertebrate limbs.jpg? Those that I know are all copyrighted but there should be such things in some of the older books that are now in the public domain (not in Owen's Mammalia, though - just checked). --Daniel Mietchen 09:19, 4 May 2009 (UTC)

End of semester here and a bit rushed, will read it asap though. Chris Day 15:13, 4 May 2009 (UTC)


I have some video material (from MR image series obtained by several projects I was involved in) on cell division and embryogenesis (paper here) as well as fossils (papers here and here, each with about 10MB of video supplement) or extremophiles (paper here, with 50MB of video supplement). I won't put them in myself, but if you think any of these would fit, just go ahead or let me know. I have not yet seen a good tool to convert avi to animated gif or other wiki-compatible format, though I could of course upload the files to some of the platforms compatible with Mediawiki's #ev extension, from where they could be embedded here. --Daniel Mietchen 10:10, 4 May 2009 (UTC)

I can't find the fossil movies, but that embryogenesis clip is awesome. I'd think that Citizendium can host movies, seeing that there are video subpages...right? In that case, you could just upload it straight to Citizendium. Otherwise, you could put it on YouTube or convert it to a GIF. I know there are quite a few freeware or shareware MOV/GIF conversion programs around. Joshua Choi 01:14, 7 May 2009 (UTC)
The fossil videos are in zip files under the "supplement" label - direct links are here and here. --Daniel Mietchen 11:30, 7 May 2009 (UTC)


Protozoans like Tetrahymena are sometimes referred to as "unicellular animals", also in the scholarly literature. I suggest to mention this broader use of the term animal somewhere in the intro. --Daniel Mietchen 16:02, 4 May 2009 (UTC)

The Animals vs. Animals

Why do you want the lede to read "The animals are etc"? Nowhere in the rest of the article do you use "the animals" instead of just plain "animals". In a million years of reading books, articles, newspapers, etc., I can't ever recall seeing this phrase being used in just this way. I might be wrong about this, but I really don't think so.... Hayford Peirce 16:17, 4 May 2009 (UTC)

  • There is, of course, the old nursery rhyme, "We went to the animal fair, The birds and the beasts were there, The big baboon, By the light of the Moon, Was combing his auburn hair." But I really don't think that counts.... Hayford Peirce 16:17, 4 May 2009 (UTC)
  • And, of course, it is also correct to write "The animal kingdom comprises etc. etc." But that's still not quite the same. Hayford Peirce 17:15, 4 May 2009 (UTC)
Oh, I'm completely neutral either way. I used "The animals ..." in the same sense as "The French are those persons that live in France" or "The archaea are single-celled organisms that cover most surfaces of the Earth". But the other way is fine too; it's not a big deal. Thanks for looking over the article! Joshua Choi 19:08, 4 May 2009 (UTC)
Ah, but "the French" refers to a specific *group*. Animals are *general*. For instance, you would write, "Europeans are those people who live in Europe; the French are those Europeans who....etc." Or so I think.... But I'm glad you don't mind the change! Hayford Peirce 20:40, 4 May 2009 (UTC)
I'm neutral either way, but feel the need to add my two cents. Animal is not a *general* when you are thinking about the whole picture. There are five (commonly known) kingdoms, so I would think using "the animals" would not be over the top. And we do refer to Europeans as "the Europeans" on occasion. As I said, I really don't care either way though.Drew R. Smith 07:37, 6 June 2009 (UTC)

No need for "References" and "Citations"

Hi, Joshua: As I mentioned on your user talk page, Joshua, I don't understand why the "References" section has a "Citations" sub-section. Since this article has only two references, that is all the more reason to raise the question of why you felt a sub-section was needed. I would suggest that you delete the "Citations" sub-header. Other than that, the article looks very good to me. Regards, Milton Beychok 17:18, 6 May 2009 (UTC)

I think I read directions on some style article to do it like that; I thought it was in CZ:Citation style, but I can't find them there anymore. You can see, though, that CZ:Citation style does put a Citations section in a References section. Oh well, I thought they were weird directions anyway. Joshua Choi 00:34, 7 May 2009 (UTC)
I have removed that "citation" subsection yesterday. --Daniel Mietchen 11:30, 7 May 2009 (UTC)