Talk:Animal

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://en.wikipedia.org/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
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)

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. Cnidaria/Placozoa/Bilateria groupings can be discussed elsewhere, let alone Deuterostomes. Jmv2009 (talk) 04:12, 19 May 2023 (UTC)

References