Talk:Animal/Archive 4

Archive 1

Archive 2

Archive 3

Archive 4

Francevillian biota

I feel like the francevillian biota should be mentioned here because of how palaeontologists think they might be the first ever multicellular life (See Francevillian biota for references)Rugoconites Tenuirugosus (talk) 06:57, 12 May 2022 (UTC)User:Rugoconites_Tenuirugosus

The Animals that form no blastula statement needs reference

"The blastula is a stage in embryonic development that is unique to animals,[15] (though it has been lost in some)" the text in parentheses needs a reference. 207.248.199.178 (talk) 21:42, 12 May 2022 (UTC)

Fixed. Chiswick Chap (talk) 11:37, 6 July 2022 (UTC)

Semi-protected edit request on 5 July 2022

Under the "Etymology" section, add the etymology for "Metazoa", which is redirected to this page: Metazoa, from Meta and Zolon, Greek for "after" and "animal" respectively, roughly translating to "late animal". Named such in contrast to "protozoa", early animals, which are unicellular. LeafStickbranch (talk) 17:12, 5 July 2022 (UTC)

Well, it's marginal, as it's not the main keyword, it's obsolete, and Wikipedia is per policy Not a Dictionary, but I've added a brief mention. Chiswick Chap (talk) 11:57, 6 July 2022 (UTC)

I'm hesitant to make the change without discussing it here first but I don't think it's accurate to just use the word "formerly" because the word is still widely in use. I understand the reasoning, and yes many academics do distinguish between Choanozoa and Metazoa, e.g. this page published in 2021 by Holt & Iudica at Susquehanna University, (or some other animal sub-groupings) but broadly the term "Metazoa" for animals seems to still be in use. Some examples, from the last few years across a range of different fields and subfields that are cited by authors other than themselves:

• Buckley, K.M.; Dooley, H. (2022). "Immunological Diversity Is a Cornerstone of Organismal Defense and Allorecognition across Metazoa". The Journal of Immunology. 208 (2): 203–211. doi:10.4049/jimmunol.2100754.
• Coppola, U.; Waxman, J.S. (2021). "Origin and evolutionary landscape of Nr2f transcription factors across Metazoa". PLoS ONE. doi:10.1371/journal.pone.0254282.{{cite journal}}: CS1 maint: unflagged free DOI (link)
• Ivantsov, A.Y.; Zakrevskaya, M.A. (2021). "Symmetry of Vendobionta (Late Precambrian Metazoa)". Paleontological Journal. 55: 717–726. doi:10.1134/S0031030121070054.
• Torres-Zelada, E.F.; Weake, V.M. (2021). "The Gcn5 complexes in Drosophila as a model for metazoa". Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms. 1864 (2): 914610. doi:10.1016/j.bbagrm.2020.194610.
• Zancolli, G.; Reijnders, M.; Waterhouse, R.M.; Robinson-Rechavi, M. (2021). "Convergent evolution of venom gland transcriptomes across Metazoa". PNAS. 119 (1): e2111392119. doi:10.1073/pnas.2111392119.

The other recent published usage that comes up a lot when you search for it (mostly in the form of book reviews) is Peter Godfrey-Smith's 2020 popular science book Metazoa: Animal Life and the Birth of the Mind, reviewed by The Quarterly Review of Biology, the Animal Studies Journal, The Philosophers' Magazine, and Environment, Space, Place, among many others. Often times the precise usage or sense is not defined but, as noted, Wikipedia is not a dictionary. Thoughts? - Procyonidae (talk) 17:12, 6 July 2022 (UTC)

Er, I answered the request by writing and citing an etymology, the question in my mind being whether it was needed, but as I said above, agreeing to include it because of the request. Your citations show that "Metazoa" is still sometimes used by biologists and others, including a popular philosopher (and I enjoy Godfrey-Smith as much as you do): but the sources do not and cannot demonstrate what you would need to show, that the term is not obsolete taxonomically: Godfrey-Smith certainly isn't a taxonomist. A better solution has however occurred to me: "Metazoa" occurs naturally in the lead section already, and I've just boldfaced it where it occurs, rather than mentioning it twice. The text already says it's a synonym, which has the benefit of being true and neutral. Chiswick Chap (talk) 17:46, 6 July 2022 (UTC)

Two things:

1. I like your fix, I think it's the best option for now and bolding the occurrence is a good idea, thanks for that.
2. In case this discussion comes up again later, maybe during an expansion or overhaul of the existing page in the future, who knows, I want to note that we don't currently distinguish between Animal (taxonomy) and Animal (biology) so an outdated taxonomic definition doesn't preclude the word from being on this page. That said, I don't even think it is "obsolete taxonomically" so much as falling out of favor and disliked by a (growing) group of academics (but WP:JDLI). It's still widely used, both in text and speech. And it's still used by the NCBI taxonomy browser.

I guess my thought is just, how are people going to be using the page? The way it's noted now in the third paragraph with the parenthetical works, I don't have any improvements there. Also want to throw in a link to the Talk page for Metazoa on Wikispecies, in case more folks want to chime in. - Procyonidae (talk) 21:26, 7 July 2022 (UTC)

Cladogram - inclusion of Lophophorata

User:Jts1882 wrote in the edit summary (7 October 2022) "This cladogram needs proper sourcing, but inclusion of Lophophorata in Lophotrochozoa is uncontroversial (and was missing)". The controversy is not the inclusion of the lophophorate phyla, but the monophyly of Lophophorata. The competiting hypothesis is Lophotrochozoa = Polyzoa + Trochozoa, where the monophylic Polyzoa contain Ectoprocta and Entoprocta, but Brachiozoa (Brachiopoda and and Phoronida) are a part of Trochozoa, maybe a sister group to (Annelida + Nemertea) - see Polyzoa is back.... In such case the phylogenetic tree needs two separate branches for the lophophorate phyla. (Sorry for my English, I hope you can understand it.) Petr Karel (talk) 07:34, 10 October 2022 (UTC)

@Petr Karel: Yes, it would have been better if I'd said "inclusion of lophopharate phyla is not controversial". After all it's in the definition of Lophotrochozoa. The thinking behind my edit was that I noticed the phylogenetic tree in the article had Lophotrochozoa containing "Annelida and allies" and "Mollusca and allies", with no mention of lophophorates. As one of the three groups in its definition this seemed a major omission. Lophophorates weren't monophyletic in Halanych's 1995 study, but some recent studies are recovering them as a clade (e.g. see Laumer et al 2019 (with Entoprocta) and Marletaz et al 2019). My impression is that Polyzoa is now out of favour.

More generally, I think the whole cladogram in the animal article is problematic as it doesn't follow any one of the sources. I have been thinking of replacing it with the consensus one in Girebet and Edgecombe's 2020 book, The Invertebrate Tree of Life (p21 or in online assets). This isn't entirely uncontroversial as they favour some of their positions (but not all), but has the advantage of being a recent secondary source with some sort of consensus phylogeny. The text could then point out the controversial areas and state alternatives. Girbet and Edgecombe do have monophyletic Lophophorata in their consensus tree (with the addition of Entoprocta).

Another issue I have noticed is the use of Spiralia and Lophotrochozoa. The cladogram uses Lophotrochozoa sensu stricto for a clade in Spiralia containing the lophophorates and trochozoas, which fits the original definition and is the usage in Girebet and Edgecombe's book. Other groups (e.g. Philippe/Telford) use Lophotrochozoa sensu lato instead of Spiralia as one branch of the major protostome division (sister to Ecdysozoa). Wikipedia articles are inconsistent. —  Jts1882 | talk  08:46, 10 October 2022 (UTC)

@Jts1882: In my opinion the use of Lophotrochozoa senu stricto, i.e. according the original definition (last common ancestor ...), is better. I think the Lophotrochozoa sensu lato were preferred as a senior synonym to Spiralia in times when Platyzoa seemed to be monophyletic - in such case it also fitted the original definition.

Problem is, that the definition sensu lato is still used in the cladististics, see Phylonyms: A Companion to the PhyloCode (2020; doi:10.1201/9780429446276; Section 5, item 191) - Lophotrochozoa are defined as the largest crown clade containing Annelida, Mollusca, Phoronida, Brachiopoda and Bryozoa but not Arthropoda, Nematoda, Echinodermata, so the composition includes also gnathiferan phyla. This could be why there are inconsistencies in the wikipedia articles.

Back to Polyzoa: According to the POV wikipedia rule we cannot forget the Polyzoa hypothesis as dead, because there is a recent study with a solid reference and without a consensus, which would rule its conclusions out. But I agree with your solution - indicating that the branch could be paraphyletic. Thanks for it. --Petr Karel (talk) 15:17, 10 October 2022 (UTC)

800mya?

In the current version of this article, it says that they started around 650mya; it could be true, but i have seen some sources (i do not now if they are reliable) say that there is evidence that Sponges existed up to nearly 800mya. (Again, i do not know if this is true, i will probably get destroyed here). Abdullah raji (talk) 11:08, 28 October 2022 (UTC)

Please provide the sources you refer to - as "some sources" is rather inadequate. --Vsmith (talk) 12:21, 28 October 2022 (UTC)

(These are probably bad but) Biotechnological potential of marine sponges-JSTOR<, Porifera organismal diversity-Ohio state university, And, on the origin of metazoan adhesion receptors: cloning of integrin a subunit from the sponge "Geodia cydonium". (:

Edit: newscientist also said they may have lived 890 mya, although even that seems a bit wild.Abdullah raji (talk) 13:06, 28 October 2022 (UTC)

The Smithsonian, in a high school study guide, gives an 800 million year figure based on DNA evidence. I don't think that is a strong enough source for this point in this article. A 2004 article in Current Science, titled "Biotechnological potential of marine sponges", has been posted on researchgate,[1] (my JSTOR account does not include access to that paper). That paper includes a comment about sponge evolution occurring 600 to 800 million years ago. I doubt that is strong enough to support stating in WP that Animals started 800 mya. - Donald Albury 13:29, 28 October 2022 (UTC)

Your citation goes to the home page of JSTOR. You need to link the full URLs of the articles you want to use. Donald Albury 15:51, 28 October 2022 (UTC)

References

On the animal tree and a new organization of article

Hey @Jts1882, just saw your latest edit on here and I think I agree with you. Since it's supposed to be a synthesis cladogram, it would be better to make it like the one in "The Invertebrate Tree of Life", which isn't biased towards the Porifera-first or the Ctenophora-first hypothesis. Also, I would like to replace these sections:

• Diversity
  • Size
  • Numbers and habitats
• Evolutionary origin
• Phylogeny
  • Non-Bilateria
  • Bilateria
    • Protostomes and deuterostomes
      • Ecdysozoa
      • Spiralia
• History of classification

With these instead, to make it clearer for the readers (and because I don't think "Size" deserves its own section to be honest, it may as well go in morphology):

• Classification and diversity (table would go here)
  • Non-bilateral animals
  • Bilateral animals
    • Deuterostomes
    • Protostomes
      • Ecdysozoa
      • Spiralia
  • Historical classifications
• Evolutionary history
  • Origin of animals ("Evolutionary origin" would go here)
  • Phylogeny (cladogram would go here)
    • Porifera-first hypothesis
    • Ctenophora-first hypothesis

Would love some feedback on this proposal before I make any changes. ☽ Snoteleks ☾ 21:47, 17 December 2022 (UTC)

Those changes look good to me. One difference is that instead of the porifera-first and ctenophora first sections there could be a more general section on the problem areas in the tree, which could be:

1. Porifera-first and Ctenophora first
2. Position of Placozoa (bilateria-sister or Cnidaria-sister)
3. Position of Xenacoelomorphs (basal bilateran, in deutrostomes or breaking deuterostome)
4. Arrangement in Spiralia

One other thing might be a second cladogram showing near relatives within Opisthokonts (or Amorphae or Holozoa). Perhaps in the Evolutionary history section? —  Jts1882 | talk  08:02, 18 December 2022 (UTC)

@Jts1882 Agreed, a cladogram for external relationships is essential. ☽ Snoteleks ☾ 15:17, 18 December 2022 (UTC)

Section Phylogeny, cladogram, position of Orthonectida and Dicyemida

1. Orthonectida identified as highly degenerate annelid worms (since 2018):
   • Refs: DOI:10.1016/j.cub.2018.04.088, DOI:10.3389/fgene.2019.00443, DOI:10.1016/j.cub.2020.01.061
   • Detailed position: Sister group to Sedentaria (Slyusarev et al. 2020) or to whole Pleistoannelida (Zverkov et al. 2019)
2. Dicyemida (syn. Rhombozoa):
   • Refs: DOI:10.3389/fgene.2019.00443, DOI:10.1093/gbe/evz157
   • Detailed position: Probably sister group to Rouphozoa (probably because the whole current lophotrochozoan phylogenetic tree needs stronger support)
3. ⇒ Mesozoa are polyphyletic group, should not be applied as valid taxon anywhere in Wikipedia.

-- Petr Karel (talk) 10:24, 20 December 2022 (UTC)

@Petr Karel Thank you, but to add to this: https://doi.org/10.1098/rspb.2022.0683 recovered a monophyletic Mesozoa positioned between Platyhelminthes and Gnathifera. ☽ Snoteleks ☾ 16:08, 20 December 2022 (UTC)

Thanks, I haven't noticed this study, I don't follow regularly the Proc Biol Sci. Of course I stop my proposal, instead I will read the article. (No hope for the final stable spiralian phylogeny?) --Petr Karel (talk) 17:07, 20 December 2022 (UTC)

@Petr Karel Sadly I don't think we'll receive a consensus on Spiralia's cladogram for a while :') we can only hope.. ☽ Snoteleks ☾ 21:25, 20 December 2022 (UTC)

I've been having a look through those references.

• Schiffer at al (2018) and Zverkov et al (2019) provide evidence that orthonectids are derived annelids. The former supports non-monophylly of Mesozoa and a position for orthonectids within annelids but the finer relationships vary from analysis to analyis. The latter has a good phylogenetic analysis suggesting they are sister to derived worms in Pleistoannelida (Errantia + Sedentaria).
• Slyusarev et al (2020) includes a figure showing Orthonectida sister to Sedentaria, but this is based on another study by Bondarenko et al (2019). This study doesn't include the figure shown and its phylogenetic analysis only includes orthonectids and annelids. As far as I can tell it shows orthonectids as sister to Hirudinea (leaches) within Clitellata in Sedentaria.
• Lu et al (2019) looks at the genomics of dicyemids and other spiralians and uses a reference phylogenetic tree based on an earlier paper by Lu et al (2017). This study finds a monophyletic Mesozoa either nested in Rouphozoa and Gastrotricha or as sister to Rouphozoa. In all analyses the mesozoans, gastrotrichan and platyhelmonthes form a clade.
• I've yet to get a copy of Drabkova et al (2022), but the abstract says they "recover Mesozoa monophyletic and as a close relative of Platyhelminthes or Gnathifera".

Both hypotheses seem to have reasonable support in the respective papers. A first impression is that studies that include more flatworms than annelids in the analyses find a relationship near Rouphozoa, while studies with more annelids find orthonectids within annelids. This makes me think of turtles and the support for an anapsid relationship when studied with primitive reptiles and support for a diapsid/archosaur relatonship when more diapsids were included. —  Jts1882 | talk  17:02, 21 December 2022 (UTC)

Thanks. I can only agree. (Free full text of Drabkova et al via ResearchGate) Petr Karel (talk) 10:43, 22 December 2022 (UTC)

References

Missing Phyla in Table

The table which lists all of the animal phyla is missing Nemertia and Cycliophora, which are included elsewhere on Wikipedia: https://wiki.riteme.site/wiki/Phylum#Animals Electro blob (talk) 23:33, 12 January 2023 (UTC)

This would be better said on that article's talk page not this one. PrathuCoder (talk) 12:55, 17 January 2023 (UTC)

(@Electro blob) I have added both Nemertea and Cycliophora today (with references). --Petr Karel (talk) 09:18, 18 January 2023 (UTC)

Peer Review

I would like to suggest this article for a peer review as a low number of major edits and discussions have occurred recently for this article. No major issues have been pointed, so a peer review would likely highlight the issues preventing this article to reach A or even FA-class. PrathuCoder (talk) 13:02, 17 January 2023 (UTC)

I have submitted the article for Peer Review today. PrathuCoder (talk) 14:53, 18 January 2023 (UTC)

@PrathuCoder Unsure of what the results are or if it even has been reviewed but I'm one of the users who pointed out several things that the article needs fixing in. Either way I'm planning on changing those things myself, but I would like to know more about this peer reviewing process, if you don't mind. ☽ Snoteleks ☾ 19:50, 8 February 2023 (UTC)

Subdivisions in taxobox

I think it is important to put subdivisions in the taxobox. The taxobox is an infobox providing an at a glance summary and knowing the content is important. Being told to see the text is not helpful and undermines the purpose of having a summary box. It's also a useful navigation tool, the one I use most often. With that said, some comments:

• The large phylogenetic list was too large and complex. Not useful for an at a glance look.
• If it needs to be collapsed it is too large. We should avoid collapsible elements as far as possible as they don't collapse in mobile, where the large size is probably even more an issue.
• Incidentally the reason it didn't work is that is because |bullets=true was set and the list had its own bullets, as well as the first element not being on a new line.

Phyla (in bold)

• • Ctenophora
  • Porifera
  • Placozoa
  • Cnidaria
  • Bilateria
    • Xenacoelomorpha
    • Nephrozoa
      • Deuterostomia
        • Chordata
        • Ambulacraria
          • Hemichordata
          • Echinodermata
      • Protostomia
        • Ecdysozoa
          • Loricifera
          • Kinorhyncha
          • Priapulida
          • Nematoida
            • Nematoda
            • Nematomorpha
          • Panarthropoda
            • †"Lobopodia"
            • Onychophora
            • Tardigrada
            • Arthropoda
        • Spiralia
          • Gnathifera
            • Chaetognatha
            • Micrognathozoa
            • Gnathostomulida
            • Rotifera
            • Acanthocephala
          • Platytrochozoa
            • Cycliophora
            • Rouphozoa
              • Platyhelminthes
              • Gastrotricha
            • Lophotrochozoa
              • Annelida
              • Mollusca
              • Nemertea
              • Kamptozoa
              • Lophophorata
                • †"Tommotiida"
                • Brachiopoda
                • Bryozoa
                • Entoprocta
                • Phoronida

  ---

  Groups of uncertain placement

  • Mesozoa
    • Orthonectida (annelid?)
    • Dicyemida
    • Monoblastozoa (doubtful existence)
  • †Kimberella (bilaterian?)
  • †Funisia
  • †Vendobionta
  • †Vetulicolia (deuterostome?)

Animal/Archive 4
Scientific classification
Domain:	Eukaryota
Clade:	Choanozoa
Kingdom:	Animalia
Subdivisions
Ctenophora Porifera Placozoa Cnidaria Bilateria (x phyla)

• I think the subdivision section should show one of the following:

1. a simple list of phyla
2. the four earliest branching phyla and Bilateria (as shown on right)
3. as #2 with the primary divisions of Bilateria

The list of phyla is still fairly large, so I favour #2 as providing a quick at a glance summary and the links to follow up for more detail. —  Jts1882 | talk  14:21, 5 May 2023 (UTC)

• Option #2 works for me, where the enormous list absolutely doesn't. Chiswick Chap (talk) — Preceding undated comment added 14:56, 5 May 2023 (UTC)

New Sister Group Position?

In at least one place in the text, it's mentioned that either Porifera or Ctenophora could be the first branching clade, though most mentions (including the cladogram) show Porifera as the outgroup.

Pretty new research using gene fusion/linkage analysis gives pretty rock-solid evidence that Ctenophora are the outgroup, not Porifera:

https://www.scientificamerican.com/article/the-closest-living-relative-of-the-first-animal-has-finally-been-found/

Schultz, D.T., Haddock, S.H.D., Bredeson, J.V. et al. Ancient gene linkages support ctenophores as sister to other animals. Nature (2023). https://doi.org/10.1038/s41586-023-05936-6

This is a pretty important page on WP so I don't want to "be bold," as it were, without some discussion. Should this be changed and incorporated? ES2 (talk) 10:45, 18 May 2023 (UTC)

It's certainly an interesting new approach and should be mentioned somewhere. However, I'd say it is too soon to make major changes based on this primary source, without support from a secondary source. The problem is that papers offering solid evidence for one or other of the two hypotheses come along every year or so and all have evidence strongly supporting their hypothesis under their assumptions and methodology. The question is, can this study convince a neutral reviewer or experts in rival camps. I note this paper adds further support for the Cnidaria-Placozoa sister relationship. —  Jts1882 | talk  12:45, 18 May 2023 (UTC)

Consensus phylogenetic tree

In light of the new evidence for the Ctenophore-sister hypothesis I suggest we replace the current cladogram, which shows Porifera-first, with one that is agnostic. I suggest the tree in The Invertebrate Tree of Life by Giribet & Edgecombe (2020), which shows a basal trichotomy with Cterophora, Porifera and ParaHoxozoa, a trichoomy between Placozoa, Cnidaria and Bilateria as the next branch, and polytomies in Ecdysozoa and Spiralia. It's a relatively recent secondary source by well-respected authors and shows all the phyla. It's not an entirely a consensus tree as it shows Nephrozoa and Deuterostomia, which have recently been challenged, but these have been well established and uncontroversial clades until the recent studies.

I have a version at User:Jts1882/phylogeny/Animals#Giribet_&_Edgecombe_(2020). This is currently over annotated (the two sets of labels on the right), but that can be edited.

I also suggest that the cladogram be followed by a short section listing the major uncertainties in the animal tree: (1) Ctenophora or Porifera first, (2) the position of Placozoa, and (3) the challenge to Deuterostomia. The questions on internal arrangements in Ecdysozoa and Spiralia are more subjects for those articles. —  Jts1882 | talk  13:16, 18 May 2023 (UTC)

The draft tree is below. —  Jts1882 | talk  13:25, 18 May 2023 (UTC)

Metazoa

Porifera Ctenophora ParaHoxozoa Placozoa Cnidaria Bilateria Xenacoelomorpha Xenoturbellida Acoelomorpha (includes Acoela and Nemertodermatida) Nephrozoa Deuterostomia Ambulacraria Hemichordata Echinodermata Chordata Cephalochordata Tunicata (=Urochordata) Craniata (incl. Vertebrata) Protostomia Ecdysozoa Loricifera Kinorhyncha Scalidophora Priapulida Nematoida Nematoda Nematomorpha Panarthropoda Tardigrada Onychophora Arthropoda Spiralia Orthonectida Dicyemida (=Rhombozoa) Chaetognatha Gnathifera Gnathostomulida Micrognathozoa Rotifera (incl. Acanthocephala) Platytrochozoa Rouphozoa Gastrotricha Platyhelminthes Cycliophora Lophotrochozoa Mollusca Annelida Nemertea Lophophorata Bryozoa (=Ectoprocta) Entoprocta Brachiozoa Brachiopoda Phoronida sensu stricto

(Animalia)

The tree is not properly resolved. i.e. I don't believe in tri- or polytomy. Chiswick Chap (talk) 16:43, 18 May 2023 (UTC)

Further, as experienced editors are certainly very well aware, piecewise assembly of phylogenies by assembling bits and bobs from here, there, and goodness knows where is called "synthesis". Chiswick Chap (talk) 17:52, 18 May 2023 (UTC)

What I'm struggling with, is that the scope of these big named articles is too large. It should be ideally be about Choanozoa, Choanoflagelates, Sponges, Ctenophora and ParaHoxozoa. There is already enough development and contention there, and information about the evolution at those levels is only going to escalate. Once stratified levels due to the lack of information now become virtually established, but disagreements and changes may occasionally keep happening. Cnidaria/Placozoa/Bilateria groupings can be discussed elsewhere, let alone Deuterostomes. Logically, discussing Deuterostomes is like discussing the deep internal phylogeny of Ctenophora.Jmv2009 (talk) 04:12, 19 May 2023 (UTC)

The scope of the article is animals and the principal division in taxonomy is the phylum. Educated lay readers will be familiar with Chordates, Annelids, Molluscs, Arthropods and some other phyla, while few will be aware of Protostomia, Deuterostomia, Ecdysozoa and Spiralia. The latter are mysterious and lack context without their component phyla. Putting the phyla in the phylogenetic tree provides a quick visual overview which doesn't require the reader to click the links or read the rest of the article. Now the list of phyla has been removed from the taxobox and the phylogenetic tree restricted to basal divisions, the article lacks a complete list of phyla and the full diversity of animals is hidden from the reader. Why make the reader work to find fundamental information when there are simple and easy-to-follow means of presenting the information? —  Jts1882 | talk  08:32, 20 May 2023 (UTC)

I agree that there should be a list (table?) of animal phyla in the article. The higher level clades are definitely mysterious, and not useful to most readers, since they are united by their evolutionary origin, and in many cases have no obvious characteristics in common. For example, echinoderms and mammals are deuterostomes – "so what?" for most readers. Peter coxhead (talk) 10:15, 20 May 2023 (UTC)

How is it synthesis when it is taken from one source? Also WP:Synthesis doesn't mean only one source can be used. It means sources can't be combined to reach a conclusion not stated in any of the sources. —  Jts1882 | talk  06:15, 19 May 2023 (UTC)

Bolting the n+1^th source on to a tree's sources is by definition creating a synthesis. The synthesised tree with clade_x+1 bolted into position_y+1 is exactly concluding with a structure not stated in any of the sources: obviously the n+1^th source gives local context where its clade is to be positioned, but unless it precisely names source n for the rest of the tree, the {n + n+1} tree is a wiki-synthesis. Chiswick Chap (talk) 06:51, 19 May 2023 (UTC)

The issue of synthesis in cladograms has been discussed a number of times recently. I would now prefer not to run together trees from separate sources into one tree (although I'm aware that I have done so in the past). If Source1 gives a high level cladogram with Clade1 as a terminal, and Source2 gives a cladogram for Clade1, then, in my view, it's better to present these separately, with a note explaining how they are connected. One problem if you run the trees together is that it's not clear how to present the references for Source1 and Source2 in a way that makes it clear which parts of the combined tree they support. Another is whether Source1 and Source2 have the same definitions of Clade1. Peter coxhead (talk) 11:19, 19 May 2023 (UTC)

All of which says, we should not be synthesising our own cladograms anywhere on Wikipedia. I think, pace Jmv2009, that we should have a reduced tree here, down to Protostome/Deuterostome, and we can indicate those groupings in the table of phyla in the 'Numbers and habitats' section. That way the article still hangs together but we avoid both the synthesis and the constant-update problems. Chiswick Chap (talk) 11:56, 19 May 2023 (UTC)

Why don't we add both Giribet's cladogram (which would not be a wiki-synthesis since it is directly from a single source), which shows polytomy (a perfectly understandable way to represent that the root is unclear), AND also a table with several reduced cladograms (down to Bilateria or Deuterostomia/Protostomia) that showcase all the different hypotheses? ☽ Snoteleks ☾ 16:12, 19 May 2023 (UTC)

Thanks for the suggestion. We seem to be coming to the view that Giribet, like earlier editing of this article, goes into too much detail, so adding Giribet and then also tabulating other authors is compounding the problem. We could use the base of Giribet - as you say, at least it's a single source - with dotted lines for uncertainty; we can't assume readers will know that's the meaning if we don't indicate it graphically in some way.

That is not synthesis according to WP:SYNTHESIS, which is the only relevant guideline. Synthesis is arriving at conclusions not contained in the sources.

Yes it is, the conclusion "this composite tree is valid" is not contained in (any of) the sources. As Peter coxhead has rightly said, none of the sources will say whether their definitions are the same as each others, unless (as I said above) source n+1 actually names source n as defining the rest of the tree. Chiswick Chap (talk) 13:03, 19 May 2023 (UTC)

However, for this discussion any mention of synthesis is irrelevant. The phylogenetic tree is based on a figure from a single source. It's a book on animals and summarises the current views on relationships between animal phyla. —  Jts1882 | talk  12:40, 19 May 2023 (UTC)

Eh, this discussion began when you added a second source yesterday, so your claim is false with respect to that original matter. The tree you're presented above has multiple *other* problems, such as not being fully resolved (as I stated above) and going into way too much depth (as User:Jmv2009 stated above). As for summarizing "the current views", there is not a single zoologist in the world who thinks that there were 3-way splits all over the tree of life. The 3-way splits may perhaps represent uncertainty averaged over different phylogenetic hypotheses, but nobody imagines that the tree as drawn represents the actual phylogenetic history. Chiswick Chap (talk) 13:03, 19 May 2023 (UTC)

Where is this second source I supposedly added yesterday? I started this section yesterday with a single source and it still has the same single source. —  Jts1882 | talk  13:13, 19 May 2023 (UTC)

Ah, that wasn't you, my apologies. I removed it for the reason stated. Chiswick Chap (talk) 14:17, 19 May 2023 (UTC)

One thing I don't like is that it treats Nephrozoa as the consensus, when as far as I can tell in the literature there is no consensus between it and Xenambulacraria. Hemiauchenia (talk) 07:14, 20 May 2023 (UTC)

Endless forms most beautiful. I've added a short account of two Xenambulacrarian phylogenies. Chiswick Chap (talk) 12:00, 20 May 2023 (UTC)

Well, we seem to be moving towards agreement that we'll use part of Giribet (even if I'm not mad keen on it, never mind), and that we'll cut down on the all-the-way-to-phylum detail which is getting more and more ridiculous as more phyla and subsubsubsubclades get added, presenting the very opposite of a welcoming overview. We have articles on all the phyla, not to mention on the major clades, so we're simply inviting double- or triple-update difficulties, not to speak of repetition. I'll have a stab at implementing the changes and people are invited to tweak the result, within reason. Chiswick Chap (talk) 18:19, 19 May 2023 (UTC)

References

Blue whale the largest?

If Supersaurus was 39 m as stated, the blue whale is not the largest (contradiction). WolfGreg9 (talk) 09:44, 9 August 2023 (UTC)

Um, we work from reliable sources not editorial inference, which is called Original Research. In any case, no reason to equate largest and longest. Chiswick Chap (talk) 11:21, 9 August 2023 (UTC)

So by "largest" you mean "heaviest"? I would call it so otherwise reads as a contradiction... WolfGreg9 (talk) 12:22, 11 August 2023 (UTC)

Only in your mind, seemingly. Chiswick Chap (talk) 14:14, 11 August 2023 (UTC)

Number of described living species?

The article lead says "2.16 million species" as of 2022, yet there is no reference for this in the text. The only data present is around 1.5 million as of 2013, in the Diversity section. —Snoteleks (Talk) 13:31, 4 September 2023 (UTC)

Apart from the lack of a source for this in the article, I'll complain about the precision. There is no estimate of animal species with three significant figures. I wouldn't give more precision than saying there are more than 2 million species, assuming a source can be found. That aside, there can be no reliable estimates as most species haven't been formally described. Estimates for insect species numbers for groups like beetles have them several fold higher than the number of described species. A quick google finds a National Geographic article on Biodiversity, which says that "Scientists have estimated that there are around 8.7 million species of plants and animals in existence. However, only around 1.2 million species have been identified and described so far, most of which are insects". I think I've seen sources for over one million described insect species. I'll dig a bit deeper. —  Jts1882 | talk  16:16, 4 September 2023 (UTC)

The IUCN estimates 74,420 described vertebrates and described invertebrates 1,521,459 pdf, which adds up to about 1.6 million described animals. The pdf breaks it down further, e.g. 1.05 million insects, 114m molluscs, 111m arachnids, and 80m crustaceans. The IUCN estimates 2.16m for total eukaryotes, which looks suspiciously like the number in the lede. —  Jts1882 | talk  16:38, 4 September 2023 (UTC)

The 8.7m comes from Mora et al (2011). and gives 7.8m total for animals, based on 960k species described. —  Jts1882 | talk  16:45, 4 September 2023 (UTC)

For another data source (taken for what it's worth), the GBIF global taxonomic "backbone" data set presently recognizes as "accepted" over 2.6 million species. Note that this does exclude all synonyms, which are not flagged as "accepted" in GBIF, nor any records GBIF classifies as "doubtful". As such, this should be a very CONSERVATIVE estimate of the number of described species. I'd go so far as to say for every name incorrectly recognized as "accepted" in GBIF, there is more than one name NOT recognized as accepted that should be. Unfortunately, the GBIF raw records don't appear to display Kingdom, unless it's in encoded form, so I can't tell you the exact proportion that are animals. It also doesn't seem to give any indication as to how many of the species are extinct. If I can dig a little deeper into the data file, I may be able to clarify one or both of these points, and if so, I'll update the note. For now, I think the estimates of only 1.2 million is a vast underestimate for described species. It's certainly over 2 million, even if all the extinct taxa are excluded. Dyanega (talk) 17:00, 4 September 2023 (UTC)

I figured out which field contained the codes for Kingdom; there are between 1.8 million and 1.9 million "accepted" Animalia names in GBIF. Using known extant/extinct taxa as reference points, however, I can't see any codes that would correspond, so I don't think GBIF is tracking this. Dyanega (talk) 20:36, 4 September 2023 (UTC)

References

We should state what all animals have in common without exception.

The second sentens says: “With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development.”

We should state what all animals have in common without exception. I know that some animals don’t move much, but which of the other five things mentioned are not common to all animals?

We should write two sentences, like this: “All animals… With few exceptions…” What should go in the first and second sentence?

Jan Arvid Götesson (talk) 08:29, 29 January 2024 (UTC)

Thanks for asking. Unfortunately it's the old schoolbook definition approach, with no answer. Animals have one thing in common: their ancestry, as they firm a clade. But this doesn't translate into any easy set of qualities which have been gained and lost over time. All the best, Chiswick Chap (talk) 08:42, 29 January 2024 (UTC)

But there must be something that all animal have in common, and is interesting enough to mention? Jan Arvid Götesson (talk) 08:48, 29 January 2024 (UTC)

Not even “breathe oxygen” is common to all animals. Henneguya zschokkei does not. That leaves only “consume organic material”, “can reproduce sexually”, and “grow from blastula” on the potential list. — Preceding unsigned comment added by Jan Arvid Götesson (talk • contribs) 07:31, 30 January 2024 (UTC)

I repeat, it's a futile approach, both non-biological and frankly unencyclopedic. Let's just give it a try: Reproduce sexually or asexually; respire aerobically or anaerobically; are terrestrial or aquatic; microscopic or macroscopic; parasitic or free-living; motile or sessile; having bilateral, radial, or pentamerous symmetry, except possibly sponges which might be entirely asymmetric; heterotrophic except for corals which have photosynthetic endosymbionts; etc. etc. etc. Really, no, thankyou, this isn't the way to go. It just isn't how we should be trying to write an even slightly scientific encyclopedia. Once again, this is not a circa-1900 elementary schoolbook laying down the law about all life being divided into animals and plants, all metabolism being either oxidative respiration or photosynthetic primary production: it all just isn't like that. Let's just drop it, please. Chiswick Chap (talk) 20:27, 30 January 2024 (UTC)

@Jan Arvid Götesson Animals are the most diversified described group, it's not a surprise that there are tons of exceptions. The text already states their main synapomorphy: blastula stage during embryonic development. Other characteristics (according to Adl et al., 2019) are: "sexual reproduction through an egg cell usually fertilized by a monociliated sperm cell with acrosome; gastrula phase that follows the blastula and allows differentiation into endoderm, ectoderm and mesoderm" (we should check if sponges share this) "basal lamina and extracellular matrix with collagen and other fibrous proteins; heterotrophic nutrition with secretion of digestive enzymes and osmotrophy through a digestive tract; ectoderm completely surrounding body, and endoderm surrounding a digestive tract; sensory cells in epithelium; nervous tissue in organized network; epithelial actin–myosin-based contractile cells between endoderm and ectoderm;" etc. —Snoteleks (Talk) 08:37, 31 January 2024 (UTC)

Indeed, and none of those complex technical details are remotely suitable for the lead, which is not just a summary but introductory for beginning-level readers. Chiswick Chap (talk) 08:55, 31 January 2024 (UTC)

@Chiswick Chap Agreed. Also some of those aren't even synapomorphies, like the collagen thing and cell-cell junctions, since they appear in Holozoa as a whole. —Snoteleks (Talk) 17:11, 31 January 2024 (UTC)

Well, exactly. Chiswick Chap (talk) 17:13, 31 January 2024 (UTC)

Wiki Education assignment: Introduction to Community Economic and Social Development II

This article was the subject of a Wiki Education Foundation-supported course assignment, between 9 January 2024 and 5 April 2024. Further details are available on the course page. Student editor(s): Rajandeep Kaur Dhaliwal (article contribs).

— Assignment last updated by Rajandeep Kaur Dhaliwal (talk) 04:21, 12 February 2024 (UTC)

Numbers and habitats of major phyla

Under the heading "Numbers and habitats of major phyla" there's a table that presents the phyla in descending order by number described species. I suggest, in the interest of presenting good information, they be ordered phylogenetically.

Also, someone should either, `1) add a column that describes the points of increasing adaptive complexity, or 2) add a table for just this purpose. Krisandtim (talk) 03:32, 11 March 2024 (UTC)

I've made the table sortable under the name and the number of species columns. To get the number of specie column to work I added a sort key using data-sort-value. Some other columns could be made sortable with appropriate sort keys.

What measure would you need for "adaptive complexity"? This would have to be sourced. —  Jts1882 | talk  07:36, 11 March 2024 (UTC)

Surely unworkable. Sounds like "higher" and "lower" by any other name. But it would be nice to have all the other columns sortable in a Boolean (yes/no) way if that can be arranged. Chiswick Chap (talk) 08:27, 11 March 2024 (UTC)

I didn't make the other columns sortable as they have a mix of yes, blanks and numbers and give a strange order. The numbers with references are treated as stings, which is why they need sort keys. Are all the blanks noes? Perhaps those columns should all have yes or no with the numbers in parenthesis. To make the column sortable, remove the class="unsortable" from the column headers.

Yes, blanks are noes, so we can begin all with yes or no followed by (details). The free-living column can't be sorted as it's all yeses, so not a lot of use in that instance. Chiswick Chap (talk) 10:53, 11 March 2024 (UTC)

Also, can we do better than the 2013 reference? —  Jts1882 | talk  10:42, 11 March 2024 (UTC)

The ref is fine. Any replacement must be comprehensive as different sources are never directly comparable, so it's far less misleading to give a set of figures from one source, of whatever date, than to hunt after recency. Chiswick Chap (talk) 10:53, 11 March 2024 (UTC)