tag:blogger.com,1999:blog-5460788270738656369.post5844365582419285702..comments2023-12-24T07:02:43.274+08:00Comments on Catalogue of Organisms: The Origin of Insect WingsChristopher Taylorhttp://www.blogger.com/profile/11075565866351612441noreply@blogger.comBlogger24125tag:blogger.com,1999:blog-5460788270738656369.post-15613667028090001952013-06-28T03:57:20.556+08:002013-06-28T03:57:20.556+08:00Christopher, Diptera spp. have 2 mesothoracic flig...Christopher, Diptera spp. have 2 mesothoracic flight wings and 2 metathoracic alteres (strepsiptera have opposite condition). <br /><br />Many 4-wing insects have knobby antennae (unlike diptera), might these function for improved flight, analogous to the halteres in some fashion? DDedenhttps://www.blogger.com/profile/10033851770461086341noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-91776928793695142152012-07-25T22:42:09.545+08:002012-07-25T22:42:09.545+08:00Christopher, what I meant was that the larvae did ...Christopher, what I meant was that the larvae did have simple air tubes to oxygenate, initially, and gradually developed independent supplementary oxygenation equipment (gills) or behavior (bubbles) depending on environmental pressures and niche advantages. <br /><br />http://en.wikipedia.org/wiki/Aquatic_insects<br />"The larvae and nymphs of mayflies, dragonflies and stoneflies still retain the air tubes they need for adult stage but when in larval stage they are equipped with gills that strain out oxygen in the water."DDedenhttps://www.blogger.com/profile/10033851770461086341noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-3971596955154330662012-07-25T22:07:02.755+08:002012-07-25T22:07:02.755+08:00Thanks for the correction, Christopher.Thanks for the correction, Christopher.DDedenhttps://www.blogger.com/profile/10033851770461086341noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-36272244040180711312012-07-25T12:31:48.559+08:002012-07-25T12:31:48.559+08:00I thought reliance on simple air tubes limited the...<i>I thought reliance on simple air tubes limited their size in water</i><br /><br />They don't have 'simple air tubes'. They have gills.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-58860354600677770222012-07-24T22:53:47.926+08:002012-07-24T22:53:47.926+08:00How could very large dragonfly nymphs obtain suffi...How could very large dragonfly nymphs obtain sufficient O2 for submerged active carnivory (fresh or brackish)? I thought reliance on simple air tubes limited their size in water, unlike the fanning adults in an high O2 atmosphere. My speculation was that the nymphs were small in water and quickly transformed into small winged adults (hexapod raptors) which remained carnivorous around open water to get protein for body growth, as opposed to mere calories for energy and some protein for egg production.DDedenhttps://www.blogger.com/profile/10033851770461086341noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-37558354947495921912012-07-24T13:02:59.642+08:002012-07-24T13:02:59.642+08:00'bu' = 'but''bu' = 'but'Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-51134640739330512092012-07-24T13:02:34.452+08:002012-07-24T13:02:34.452+08:00If those nymphs were restricted to freshwater, it ...<i>If those nymphs were restricted to freshwater, it suddenly makes sense AFAIK, because most Palaeozoic sites are marine or brackish to some extent.</i><br /><br />At least some Odonata have nymphs that are able to live in brackish water, bu in general your point stands.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-69963031524350864182012-07-23T17:54:49.893+08:002012-07-23T17:54:49.893+08:00Though all the usual caveats around negative evide...<i>Though all the usual caveats around negative evidence still apply, the near or total absence of aquatic nymphs from Palaeozoic deposits contrasts strongly with their later abundance in Mesozoic and Cenozoic deposits, especially when one considers the presence of Carboniferous stem-dragonflies far larger than any later successor (such as the two-foot-plus-wingspan </i>Meganeuropsis permiana<i>) that might be expected to have had similarly robust nymphs.</i><br /><br />If those nymphs were restricted to freshwater, it suddenly makes sense AFAIK, because most Palaeozoic sites are marine or brackish to some extent. Many coal forests were mangroves.<br /><br /><i>Unfortunately, many of the supposedly exite-bearing specimens described by Kukalová-Peck remain in private collections and are not readily available for re-examination.</i><br /><br />HULK SMASHDavid Marjanovićnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-80820920775971844842011-03-05T08:40:53.853+08:002011-03-05T08:40:53.853+08:00AFAIK = 'As far as I know'AFAIK = 'As far as I know'Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-62101392261207777052011-03-02T04:40:08.553+08:002011-03-02T04:40:08.553+08:00I must be slow; what is AFAIK?I must be slow; what is AFAIK?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-53200971837794753392010-11-29T22:34:57.315+08:002010-11-29T22:34:57.315+08:00I'm sure you know of the fruit fly mutation wh...I'm sure you know of the fruit fly mutation where wings grew where eyes should be and legs grew where antennae should be; eyes (transparent lens) are never on the thorax AFAIK, (often transparent) wings are, I consider them as derived from the same primitive organ.DDedenhttps://www.blogger.com/profile/10033851770461086341noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-10592378280442704042010-11-29T21:05:21.134+08:002010-11-29T21:05:21.134+08:00I'd missed that the styli were also present in...I'd missed that the styli were also present in the thorax of archaeognaths (I've inserted a correction to that effect in the post). However, Grimaldi and Engel (2005) also note that the thoracic exites in archaeognaths lack associated musculature, so an exite origin for wings would still require a certain degree of parallelism in archaeognaths and thysanurans (not impossible, as noted in the post).Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-68328193739447921532010-11-25T17:04:55.747+08:002010-11-25T17:04:55.747+08:00The author of this blog post said:
"Also prob...The author of this blog post said:<br />"Also problematic is the complete absence of thoracic leg exites in any living insect, including archaeognathans and silverfish"<br /><br />This is factually incorrect. Indeed many Recent species of Archaeognatha do possess thoracic exites on the coxae of the mid and hind legs! <br />(e.g. see Grimaldi & Engel, 2005, Fig. 5.1)Dr. Günter Bechlyhttps://www.blogger.com/profile/03972774678090366711noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-28981270049338083042010-02-16T01:56:14.924+11:002010-02-16T01:56:14.924+11:00There's never paranotal lobes and wings on the...There's never paranotal lobes and wings on the same segment.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-64375329381767655522010-02-16T01:23:57.575+11:002010-02-16T01:23:57.575+11:00If wings were derived from paranotal lobes, how co...If wings were derived from paranotal lobes, how could paranotal lobes & wings could have been present on some species at the same time? Does this mean some pairs of paranotal lobes evolved into wings, while others remained as lobes?AYDIN ÖRSTANhttps://www.blogger.com/profile/09891160904748206385noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-42365064638762481522010-02-14T18:30:58.010+11:002010-02-14T18:30:58.010+11:00How did legs sprout from legless ancestors? Sounds...How did legs sprout from legless ancestors? Sounds like a tale!DDedenhttps://www.blogger.com/profile/10033851770461086341noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-73467891597819632902010-02-09T21:55:53.617+11:002010-02-09T21:55:53.617+11:00Arthropods and vertebrates have no legless ancesto...<i>Arthropods and vertebrates have no legless ancestors, since jointed legs derive from oral digital apparati AFAICT.</i><br /><br />Ummm.... say wha..?Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-20684525068638611802010-02-07T17:46:45.909+11:002010-02-07T17:46:45.909+11:00"closely related genes are involved in the de..."closely related genes are involved in the development of arthropod and vertebrate legs, despite the origins of both from legless ancestors" How? <br />Arthropods and vertebrates have no legless ancestors, since jointed legs derive from oral digital apparati AFAICT.DDedenhttps://www.blogger.com/profile/10033851770461086341noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-82934393764634342612010-01-21T08:16:43.075+11:002010-01-21T08:16:43.075+11:00Cool post. I've been interested in this for a ...Cool post. I've been interested in this for a while, but not enough to actually chase down any of the most recent literature. Thanks for the state-of-the-science report.Dr. Vectorhttps://www.blogger.com/profile/01257878915555113427noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-14834110296006499832010-01-18T12:21:05.085+11:002010-01-18T12:21:05.085+11:00Chris Taylor-- Thanks for reply! That was very he...Chris Taylor-- Thanks for reply! That was very helpful.Allen Hazenhttps://www.blogger.com/profile/05098575774774203097noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-23507556925213676962010-01-17T17:24:12.412+11:002010-01-17T17:24:12.412+11:00Yes, support is currently strong for Crustacea + I...Yes, support is currently strong for Crustacea + Insecta to the exclusion of myriapods and chelicerates, but at present there's no real confidence about whether or not crustaceans are paraphyletic. The main contenders (in terms of living taxa only) are probably "insects as sister group to crown crustaceans", "insects as sister to branchiopods" or "insects as sister to malacostracans" but I really wouldn't want to be laying out my bets as yet.<br /><br />In terms of hexapod monophyly, monophyly of insects in the strict sense (archaeognathans, thysanurans, pterygotes) is pretty rock solid and I'm not aware of anyone who has suggested otherwise. However, recent molecular analyses suggest that the other hexapod groups (springtails, proturans, diplurans) may not form a clade with insects. I'm still personally rather skeptical of hexapod polyphyly, but I still thought it safest to leave non-insect hexapods out of the discussion for now. If hexapods are monophyletic (as the morphological data still supports), then that makes it more likely that thoracic exites were lost some time prior to the origin of wings (springtails and such don't have exites either).Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-8657061839934595322010-01-17T16:12:10.018+11:002010-01-17T16:12:10.018+11:00My impression (I'm afraid I'm a vertebrate...My impression (I'm afraid I'm a vertebrate chauvinist, and don't follow the arthropod literature very closely) is that (molecular in particular) evidence was solidly in favor of a close relationship between Crustaceans and Insects-- to the extent of extant Crustacea being paraphyletic with regard to insects. Is this the right impression to have? And is the placement of the silverfish (and the non-Insect hexapods) in this scheme something the people who study arthropod phylogeny feel confident about?<br /><br />(B.t.w.: thanks for intersting state of play account: I wasn't really aware of the alternatives to Kukalova-Peck's theory.)Allen Hazenhttps://www.blogger.com/profile/05098575774774203097noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-82401290945804046302010-01-17T14:02:19.725+11:002010-01-17T14:02:19.725+11:00Genetic co-option or reactivation would be a kind ...Genetic co-option or reactivation would be a kind of unification of the two, but it's still an area where (as far as I know) our understanding of the processes involved is still at the early stages.<br /><br />Some authors have suggested a 'hybrid' origin of wings. Insect wings are constructed from distinct dorsal and ventral layers, and some authors have suggested that the dorsal layer may be derived from thoracic lobes (supplying the wing plane) while the ventral layer might be derived from exites (supplying the articulation). It's an interesting idea, but it currently lacks evidence.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-27556384098667578862010-01-17T13:11:35.555+11:002010-01-17T13:11:35.555+11:00The origin of insect wings is something I've o...The origin of insect wings is something I've often wondered about--thanks for detailing it! It seems like both theories have merit. This may be a silly question, but could the two be united somehow?Zachhttps://www.blogger.com/profile/08692080707969333711noreply@blogger.com