Talk:Opisthokont

Picture

This page needs a new picture. The current one is pretty weird.

Number of Species

This page should say how many species are in the phylum. --Savant13 20:32, 21 December 2006 (UTC)

Created a new page on Choanozoa. --Kupirijo 15:02, 19 October 2006 (UTC)

Parasites

So should all animals be defined as parasites, as, like their ancestors the fungi, they are living off of other organisms?

yes, parasites

Photosynthetic plants are the primary producers of the fixed carbon compounds that virtually all animals eat. Therefore, in some strict sense of the word parasite, all non-photosynthetic organisms are parasites of photosynthetic organisms. Photosynthetic organisms are parasites of the sun's energy. Further discussion belongs under thermodynamics, or under semantics of the word "parasite". (However some bacteria grow using mineral substrates thereby creating biomass that is not of photosynthetic origin. I believe that non-photosynthetic biomass is not a significant proportion of the photosynthetic biomass but I do not know of an estimate of the rate or abundance of non-photosynthetic biomass.)

Note also that fungi are not the ancestors of animals; animals and fungi are thought to have a common ancestor.

Twbeals31 16:39, 19 February 2007 (UTC)

Because there are organisms that make their own food without sunlight, the best term to use here would be autotrophs. Autotrophs are all organisms that make their own food. (Auto=self troph=nourish) I'm also unsure of how significant a presence non-photosynthetic autotrophs have, but they do exist, so simply saying "photosynthetic organisms" limits accuracy. Also, would decomposers classify as parasites? They don't make their own food, but they aren't feeding off of another living organism. Just a thought. --Joanna 14:32, 17 March 2007 (UTC)

If you're going to stretch the word parasite to include predators, how about stretching it even further? What about creatures who do create their own food, but need other creatures for reproduction for instance? Seriously though, the normal definition requires a prolonged and intimite relationship between the organisms. So *chomp chomp* ‘nice knowing you, it was worth every second, all five of them’ doesn't quite count. Shinobu (talk) 10:46, 27 December 2008 (UTC)

Posterior vs. Anterior - Just Curious

The "Flagella" section explains that whether the flagellum/flagella are posterior or anterior is a determining factor in this classification. However, how do you determine posterior or anterior on a single cell? A brief explanation about this would improve the article IMHO. Krellkraver (talk) 01:12, 17 December 2011 (UTC)

One usage is related to the direction of movement caused by the flagellum: is movement away from the flagellum (it acts like a boat propeller) – then the flagellum is posterior; or towards it (it acts like helicopter blades) – then the flagellum is anterior. Peter coxhead (talk) 20:22, 17 December 2011 (UTC)

Monophyly of Opisthokonta

As written, the text implied that the monophyly of the opisthokonta was only supported by "some" studies whereas it is very robustly supported and widely accepted. The questions raised by Philip et al. in 2005 were quickly answered, and most researchers working on the eukaryote tree (including the many authors of "The Revised Classification of Eukaryotes," Adl et al, 2012) accept the group as a clade. The findings of Philip et al. were, as Huang puts it, likely due to "intrinsic limitations in the data", resulting from the fact that it was "based on few taxa only and included genes with conflicting evolutionary histories." (Huang et al., 2005) Parfrey et al. found opisthokonta robustly supported. See also Steenkamp et al., 2006 and Torruella et al, 2012.Deuterostome (talk) 18:40, 26 May 2014 (UTC)

Temporal Range

Shall we bump up the temporal range to 975 Ma? The page for Holozoa has 975 Ma as its start of the temporal range, and Holozoa is part of the opisthokonts, yet the page for Opisthokonts has 632 Ma as its start of the temporal range (correct me for any grammatical errors, by the way). Even more, kingdom Animalia has 670 Ma as its start, so wouldn't it make sense to make the start of the Opisthokonts as 975 Ma?

All of these temporal ranges in taxoboxes should be based on reliable sources in the article, so if there's such a source, then, yes, increase the temporal range. Peter coxhead (talk) 11:24, 5 November 2017 (UTC)

Currently looking for a good source that supports a date of ~1300 mya for first appearance of Opisthokonta in temporal range. Current taxobox has oldest fossil as 632 ma as sourced, but average of all molecular clock analyses in same source estimates 1389-1240 ma. Cladogram in article dates Opisthokonta to 1300 ma, but other editors have added, or suggested, various unsourced figures (975, 1000, 1100, 1481, 2200 ma). Loopy30 (talk) 17:46, 1 December 2018 (UTC)

We can't have editors adding unsourced dates to any articles. There have been a few IPs about who have attempted to change whole batches of articles to their unsourced dates. Any dates we provide must be from good secondary sources per WP:SCIRS. Chiswick Chap (talk) 19:45, 1 December 2018 (UTC)

Clade names and articles

I think that too many articles have been created for clade names that have limited use in the literature. The Adl et al. (2018) update of their 2012 classification seems to me likely to command wide support. Down to 2 levels below Opisthokonta it picks out (via bullets) only:

• Opisthokonta
  • Holozoa
    • Ichthyosporea
    • Filasterea
    • Choanoflagellata
    • Metazoa
  • Nucletmycea
    • Rotosphaerida (which we have at Cristidiscoidea, I think)
    • Fungi

Some other clades that have articles here (e.g. Choanozoa) are mentioned, others not at all (e.g. Filozoa). There's no need to have an article on every clade in a cladogram; many can be discussed in the text of an article on the major clades, with appropriate redirects. Apart from any other reason, many of the minor clades have not proved to be stable over time. Peter coxhead (talk) 11:16, 28 October 2018 (UTC)

Filozoa [doi:10.1371/journal.pone.0002098] and Choanozoa/Choanimal/Apoikozoa have been fully stable in content, (not in name) as since 2008/2003.

Syssomonas - Corralychtrium - Ichthyosporea - Filozoa could be unresolved holozoa? Jmv2009 (talk) 21:40, 29 October 2018 (UTC)

Stability of name is vital, though, otherwise articles are constantly being moved, with all the disruption that involves. The key point I'm making is we don't need to have an article on every intermediate clade. Peter coxhead (talk) 09:23, 30 October 2018 (UTC)

I would actually start with merging articles for the SAME node. Especially (former) paraphyletic ones. What is the difference between these REALLY. E.g. charophyta/streptophyta. What is the difference these days between Plantae/chlorobionta/Viridiplantae and green algae(granting Embrophyta)? Fish/craniata/vertebrata. Monkeys/simians. I would also focus such articles more on the differences between "basal" clades. E.g. at animal, focus on differences up to e.g. bilateria. Deeper differences can be discussed in more focused articles. Why discuss that some craniata can fly?

Moreover, at stable nodes are typically associated with more significant evolutionary steps, and more to discuss. At less fully established nodes, it's easier to refer to an extra article for alternative hypothesis, rather than generate more confusing and less focused articles: Without an article to refer to, one may need to more fully discuss alternatives. I don't like long, convoluted articles.

Species are generally notable Wikipedia:Articles_for_deletion/Common_outcomes#Species. I don't think it's a stretch to extend this to extinct ones associated with these nodes. At least it's not noted that extinct ones are excepted

I would dispute the characterization of "minor" clades as misdirected, despite their sometimes contested affiliation especially if extant. These are rare glimpses into the emergence of very important groupings. Jmv2009 (talk) 18:08, 30 October 2018 (UTC)

Well, to answer you properly would require an essay, I think! I'll make just a few brief points:

• Notability is determined by human interest. Page views, number of mentions in reliable sources, etc. suggest the articles to be expanded, which is why birds and their dinosaur ancestors get much more attention than deeper nodes.
• The number of interior nodes in a cladogram depends on the number of terminals studied. To that extent, most interior nodes are just artefacts of the few fossils known and the small proportion of taxa that didn't go extinct. What matters is whether these nodes correspond to important suites of apomorphies.
• There's a reason for the relatively small number of ranks in the Linnaean system – it makes it possible to learn them and grasp the overall pattern.

Peter coxhead (talk) 21:38, 30 October 2018 (UTC)

The 9-odd number of ranks in the Linnaean system is of course not sufficient to describe the evolution of e.g. a human being. Right now on the wikipedia taxonomy system, humans are ~67 levels deep, maybe a ~70 if you include the evolution of Archaea. However, the number of "features" in a human being certainly exceeds this number. So these levels are still only glimpses of the evolution. E.g. going from Choanoflagelata to Bilateria: 3 levels or so, corresponding to huge levels of increase in organisation, from single cells to a fully formed worm-like creatures, including nervous systems. We are only at the beginning of understanding, still disputing about this limited number of levels. A more appropriate level of complexity would by ~40000, corresponding to the number of genes, and that's not even counting epigenetics, nor variations/evolution of these genes. The number of levels being actually used is naturally expanding with the level of understanding. Initially there were only 9, and even at that limited level of classification probably most classifications were in error. And yes, in a fully resolved cladistic system, naturally every newly discovered organism gives two new species: one for the organism, and one for the historic dated node where it joins the tree. I don't know why you would call these rare glimpses of milestones "just artefacts". The diminutive size of these organisms is also no factor in determining their importance. By omitting/merging e.g. 3 levels out of 70 levels, one would approximately remove 4% of evolution. That's e.g. your liver, nails and hemoglobin, and much, much more. We can argue about whether that's a fair comparison. Probably also omitting/merging millions of generations. A pattern with only 9-odd radiation levels is grossly misleading. Evolution is not irreducably complex, just monstrously complex.Jmv2009 (talk) 02:53, 31 October 2018 (UTC)