Wikipedia talk:WikiProject Geology/Cambrian explosion

Please feel free to discuss the operation of this task force here.

Discussion about the Cambrian explosion article would be better directed to its talk page.

Microbial mat

I've added Microbial mat to the Task List. I know it wasn't originally there at all (I created it while editing Cambrian substrate revolution because I could see a large number of potential wikilinks), and it's been rated "B-class" + "High-importance". But Smith609 and I know that a lot of work is needed, since:

• neither of us has great confidence in Krumbein et al, which is cited all over the article.
• it is also very reliant on Nesbitt & Fowler, which is more credible but still openly a little speculative. -- Philcha (talk) 08:29, 21 July 2008 (UTC)

Opabinia

I'm surprised at Opabinia′s low priority, as it's the poster-child for "short, abrupt" view of the CE, e.g in Wonderful Life. -- Philcha (talk) 10:18, 23 July 2008 (UTC)

Raising to High High importance, target GA. -- Philcha (talk) 13:33, 30 July 2008 (UTC)

Halkieria

I'm adding Halkieria - High importance, target GA - because possible stem group of molluscs & annelids, and appears early. -- Philcha (talk) 13:33, 30 July 2008 (UTC)

Wot, no deuteros?

I'm surprised that the only deuterostome on the list is Pikaia. I would not quarrel with its "Low" importance, since Chengjiang contained 2 bona fishes – but they are not listed in Wikipedia:WikiProject Geology/Cambrian explosion! -- Philcha (talk) 13:43, 30 July 2008 (UTC)

The list simply contains articles that were in one version of the CEx article that I thought needed work. Add other articles at your leisure! Martin (Smith609 – Talk) 18:27, 26 August 2008 (UTC)

Articles about lagerstätten

We need to sort out a general structure for articles about Cambrian lagerstätten and their fauna. When I looked at WP:CEX and saw that Chengjiang fauna needs work, I found that Chengjiang fauna redirects to Maotianshan shales, where 90% of the content and all of the Talk are about the fauna. This looks wrong, as scientific artcles uses mainly "Chengjiang fauna" and only mention Maotianshan in the intros, describing where the critters were found. Then I found that Burgess shale type fauna describes critters from Sirius Passet, Chengjiang and Burgess Shale.

So I propose:

• Articles about the fauna should be titled "... fauna"
• Articles about the fossil beds should be separate so that they can:
  • Handle location, paleolocation, geology, taphonomy, etc.
  • Act as hooks for any notable non-animal biota found there.
• Re Burgess shale type fauna, at present I'm not sure it has a role, and would divide its content between the individual "... fauna" articles.
• "Burgess shale type preservation" is a phrase I've seen in journals, but Burgess shale type preservation seems to say as much about the deduced paleo-topography of the site, especially of the Phyllopod Bed from which most of the fossils come, as about the process of preservation, the time and duration of that preservational window, why the window opened and closed, etc. I'd move the topography material to Burgess Shale. -- Philcha (talk) 13:39, 21 August 2008 (UTC)

That sounds eminently sensible, on the whole. "BS-type fauna" is quite a common term but is perhaps self explanatory, if BS-fauna is linked to. Feel free to move content about as you like - I added it as I came across it in perhaps a haphazard way. Although the taphonomic setting is an important factor in the preservation. Martin (Smith609 – Talk) 15:00, 27 August 2008 (UTC)

Clade & cladistics

WP:CEX' to-do list includes Clade (importance High, target GA). I've had a look at both Clade and Cladistics, and done a little Googling. IMO Cladistics and related articles have reasonable content but significant gaps and are poorly sourced - in short, they neeed a mini-taskforce approach. In fact a taskforce should IMO start with Taxonomy. This article very sensibly looks at a wide range of uses of "taxonomy" - unlike e.g. articles on anatomy, which are far too human-oriented.[1] So an article is needed on biological taxonomy, and there's no link to such an article in Taxonomy at present. I'm thinking of an overall structure like:

• Taxonomy
  • biological taxonomy
    • Cladistics
      • cladistics sub-topics
    • Linnean system
      • Linnean system sub-topics
    • any other systems of biological taxonomy?

I think this is too much for us to take on, as our own to-do list is the foothills of Everest.

[1] For example Protostome and Deuterostome can't link to Anus, which dives (!?) almost immediately into sexuality. -- Philcha (talk) 09:13, 24 August 2008 (UTC)

Most of the pages do exist and are at a reasonable standard - I've added a couple of links, perhaps it would be appropriate to add a few redirects here and there. Cladistics is poorly structured, but more information-rich than I had suspected. Of course, there's scope for more expansion, but I think it covers the topic in the detail needed for WP:CEX. Clade doesn't look as dreadful as I remember it, either. I think that what is important for us is that a reader can go there and understand what a clade is; it can't hurt to clean the article up and get it to a concise GA, and the topic is an important one, but perhaps it falls slightly outwith the CEX remit.

Oh, and there's definitely cause for the creation of a separate "Human anus" article. I might create it now to avoid being inadvertently confronted with freshly shaved nether regions again... Martin (Smith609 – Talk) 14:01, 27 August 2008 (UTC)

Even better, we should propose renames of Anus and Suture to Human anus and Suture (surgical) - the latter has been on my agenda for over a year (see Talk:Suture, ever since I discovered the paleo importance of Suture (anatomical). Then we can deal with Coelom. The bloody medics are narrow-minded as well as potty-minded. The medics can't object, as none has responded to my proposal re Suture. Then I'll upgrade the refs in Suture (anatomical) and go for GA on the lot - see Wikipedia:Village_pump_(policy)#Short_articles. -- Philcha (talk) 14:23, 27 August 2008 (UTC)

Oh, I see what you were doing while I was typing my previous post. If you're ready to pitch into the debate (which I don't seriously doubt) I'll deal with the rest. -- Philcha (talk) 14:27, 27 August 2008 (UTC)

Blimey, you type a lot faster than I do! -- Philcha (talk) 14:48, 27 August 2008 (UTC)

WP:CEX may now have to do something serious with coelom, protostome and deuterostome to justify our imperialism. I think that's fairly long and complex. I'll start by looking at Kimberella to see if I can remind myself of the sources I found while persuading the GA reviewer not to go too far into proto/deutero - I'll create a section at Talk:Protostome for sources I find re the proto/deutero split. -- Philcha (talk) 15:11, 27 August 2008 (UTC)

Convergent evolution

Hi, I decided to take a quick look at this page. I don't think there's much more to say that what's there, but it's not one of my finest works. Comments are welcome, please! Martin (Smith609 – Talk) 02:08, 7 October 2008 (UTC)

Without looking anything up, just based on vague memories of articles I've edited recently, there's quite a lot more, with sources. I suspect Googling for "convergent evolution convergence convergently" using advanced search restricted to Wikipedia would get quite a lot. A few items that spring to mind:

• Bats' and birds' wings.
• "Rampant convergence" in spiders' webs.
• There's got to be something in Halwaxiid.
• Convergent evolution of Malphigian tubules in terrestrial members of arthropod sub-phyla, with loss of nephridia.
• Convergence of segmentation in annelids and arthropods, if the Ecdysozoa / Lophotrochzoa split is right.
• Coelom in protostomes and deuterostomes.
• Camera eyes - how many times?
• Venomous fangs in spiders, ants, snakes & beaded lizards.
• Warm-bloodedness in mammals and in birds / dinos.
• Problem-solving intelligence in spiders, octopuses, birds and mammals.
• In cladistics, "parsimony" = "minimum of convergences and reversals" (in PAUP).
• There have to be examples in our articles of convergence either confounding phylogenetic analyses and / or invoked as "get out of jail" cards. -- Philcha (talk) 17:03, 20 October 2008 (UTC)

Given my own personal research biases, I'd have to suggest that you go ahead and include insects as examples of convergence in flight - they have wings which perform the same function, but then you can conveniently demonstrate them as an obvious outgroup when compared to the descendants of tetrapods. Or maybe that would be tossing too many ideas at people at one time?

Would it also be worthwhile to point out that neutral convergence exists for things like DNA sequences, where random chance (n ~ 1:4) or chemical probability (C-->G swaps) will create similar sequences? Aderksen (talk) 20:31, 20 October 2008 (UTC)

I've tried to avoid turning the article into a list of examples of convergent evolution, because I think the focus should be on the concept. I think it's more beneficial to keep the article short and concise so the points are clear than to try and make it fully comprehensive, which may be an impossible task! By the way, I've copied this discussion to the article's talk page; it may be more appropriate to respond there. Martin (Smith609 – Talk) 21:14, 20 October 2008 (UTC)

Bringing things together

I think we've reached a stage where some of our work is worth showcasing, and I thought that at some point it might be helpful to produce a navigation box so readers on any C-Ex related page can easily navigate the key players and concepts. What do you think about the prototype displayed here, which was inspired by the one at Evolution? Edits and comments are welcome! Martin (Smith609 – Talk) 03:26, 22 October 2008 (UTC)

A few comments - horrendously belated, sorry, I missed it in my over-stuffed watchlist:

• In "Fossil localities" I'd add the Namibian sites (Nama Group) where IIRC significant Late Ediacaran fossils have been found. And possibly other major Ediacaran sites, as part of the mystery is whether / to what extent Late Ediacaran critters were close precursors of modern taxa. --Philcha (talk) 07:26, 20 June 2009 (UTC)
• "Themes" looks a bit patchy and unbalanced. We probably need to fix this as we improve specific articles. --Philcha (talk) 07:26, 20 June 2009 (UTC)

Crown group

Could someone take a look at this article to confirm that it's up to B-class and suggest any improvements? Thanks, Martin (Smith609 – Talk) 20:00, 25 October 2008 (UTC)

RfC

Please see Template talk:Geological range#RfC: Rewording of "fossil range" for a proposal to modify the fossil range template. Thanks! Bob the Wikipedian ^{(talk • contribs)} 03:19, 18 December 2010 (UTC)

Project banner

I have added this task force to the {{WikiProject Geology}} banner. See WP:WikiProject Geology/Cambrian explosion#Project banner. I have also added this banner to all the articles from C class up. RockMagnetist (talk) 17:59, 14 March 2012 (UTC)

Singular or plural?

Hello,

The lead to the Cambrian explosion currently reads "Phylogenetic analysis has been used to support the view that during the Cambrian radiation, metazoa evolved monophyletically from a single common ancestor: flagellated colonial protists similar to modern choanoflagellates."

Should "flagellated colonial protists" be changed to "a flagellated colonial protist"?

A universal common ancestor for all metazoa analogous to the Last universal ancestor for all life?

Thanks,

JS (talk) 21:14, 24 September 2015 (UTC)