{"id":139893,"date":"2011-12-27T14:07:47","date_gmt":"2011-12-27T13:07:47","guid":{"rendered":"http:\/\/www.madrimasd.org\/blogs\/universo\/?p=139893"},"modified":"2011-12-27T14:07:47","modified_gmt":"2011-12-27T13:07:47","slug":"del-suelo-al-cielo-sobre-el-origen-de-los-insectos-alados","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/universo\/2011\/12\/27\/139893","title":{"rendered":"Del Suelo al Cielo: Sobre el Origen de los Insectos Alados"},"content":{"rendered":"

Me encontraba leyendo una noticia sobre el origen de los insectos alados<\/strong> <\/span>cuando detect\u00e9 que se hablaba de \u201cexcavaciones en el lecho de un r\u00edo<\/strong><\/span>\u201d. Sabiendo sobradamente que el suelo es un recurso natural que se les atraganta a los periodistas y colegas de otras disciplinas (alg\u00fan\u00a0 d\u00eda \u201cmorder\u00e1n el polvo<\/em>\u201d) me puse yo tambi\u00e9n a \u201cexcavar en el ciberespacio<\/strong><\/span>\u201d. Y, como era de esperar, me top\u00e9 con el suelo, en principio del Cret\u00e1cico y despu\u00e9s, retrocediendo en el tiempo, hasta el Dev\u00f3nico<\/strong><\/span>. Eso s\u00ed, todo el material recopilado es muy difuso en este asunto. Ahora bien, si he entendido correctamente tal galimat\u00edas acerca de la filogenia de los artr\u00f3podos, y en especial del origen de los insectos alados, sus ancestros parecen resultar ser organismos del suelo<\/strong><\/span>. Quede claro que los autores del\u00a0del hallazgo, \u00a0del que se hace eco la nota de prensa que bordamos de hoy, reconocen que da lugar a postular una hip\u00f3tesis (\u00a1aleluya!: parece que son unos chicos responsables), no\u00a0una teor\u00eda cient\u00edfica\u00a0incuestionable. Pero todo ello no debiera extra\u00f1arnos<\/strong><\/span>. Por lo que se sabe hasta le fecha, la invasi\u00f3n de la tierra emergida por los organismos oce\u00e1nicos acaeci\u00f3 fundamentalmente <\/span><\/strong>(que no siempre) v\u00eda subacu\u00e1tica, al ascender la vida por las redes fluviales, adapt\u00e1ndose al agua dulce<\/strong><\/span>. De este modo, llegaron sumergidos a los confines m\u00e1s insospechados de los continentes, utilizando las arterias de Gaia como autopistas<\/strong><\/span>.\u00a0\u00a0\u00a0\u00a0\u00a0<\/p>\n

\"lecho-de-un-rio-fuente-walalariver\"\u00a0<\/p>\n

Lecho de un R\u00edo. Fuente: Walalariver<\/a><\/p>\n

<\/p>\n

Los suelos, sumergidos o no, ofrecen un refugio a los organismos acu\u00e1ticos. Debemos recordar que, aun hoy en d\u00eda todos los microorganismos y peque\u00f1os invertebrados (microfauna) siguen habitando en el medio acuoso <\/strong><\/span>(nem\u00e1todos, rot\u00edferos, tard\u00edgrados, etc.). Se trata de micro-h\u00e1bitats que se ubican entre los poros y rodeando los agregados del suelo<\/strong><\/span>. \u00a0Y tal hecho acaece aunque el medio ed\u00e1fico, aparentemente, nos parezca seco. Posiblemente, a lo largo de eones, sequ\u00edas (cambios clim\u00e1ticos) que induc\u00edan a que muchas cuencas de drenaje a penas acarrearan agua, generaron el estreses ambientales que promovieron mutaciones. Estas \u00faltimas, a la postre, dieron lugar a organismos adaptados a la vida a\u00e9rea, algunos de los cuales terminaron por salir \u201cvolando\u201d<\/strong><\/span>, incluyendo a esos malditos mosquitos. Los cauces fluviales, por alcanzar cualquier lugar de la superficie emergida de la biosfera, toparon con todo tipo de h\u00e1bitats y condiciones ambientales, dando lugar a que los organismos acu\u00e1ticos tuvieran, tarde o temprano que enfrentarse a cualquier vaiv\u00e9n ambiental<\/strong><\/span>. \u00a0Valga este post tan solo como un bot\u00f3n de muestra m\u00e1s de la importancia de los organismos ed\u00e1ficos (mayoritariamente acu\u00e1ticos) en el desenfreno posterior de la diversificaci\u00f3n de la vida terrestre<\/strong><\/span>. \u00a0Soslayo traducir el material que muestro abajo, por cuanto no se me antoja lo suficientemente interesante para los intereses de esta bit\u00e1cora. Tambi\u00e9n debo reconocer que me pierdo en un tema que apenas conozco. Basta con buscar en los textos que a continuaci\u00f3n os expongo ese extra\u00f1o vocablo suahile\u00f1o \u201csoil\u201d que en cristiano corresponde a la palabra suelo.\u00a0\u00a0\u00a0<\/p>\n

\u00a0\"o_lakef\"<\/p>\n

Cuencas de drenaje: arterias de Gaia que alcanzan los lugares m\u00e1s inh\u00f3spitos de los continentes<\/span><\/p>\n

Juan Jos\u00e9 Ib\u00e1\u00f1ez <\/strong><\/span><\/p>\n

Nuevas pistas sobre la evoluci\u00f3n de los insectos<\/a><\/h3>\n

El grupo de trabajo dirigido por el Arnold H. Staniczek y G\u00fcnter Bechly, ambos expertos en insectos, determin\u00f3 que estos f\u00f3siles representan parientes que se extinguieron en la modernidad \u00bf\u00bf??<\/span><\/em><\/strong>.<\/span><\/em><\/p>\n

FUENTE | La Raz\u00f3n digit@l<\/a> 20\/07\/2011<\/p>\n

Debido al descubrimiento de ejemplares adultos con alas, y larvas en excelente estado de conservaci\u00f3n, los cient\u00edficos fueron capaces de aclarar la posici\u00f3n filogen\u00e9tica de estos animales y se present\u00f3 una nueva hip\u00f3tesis<\/strong> sobre las relaciones de los insectos alados<\/strong>.<\/p>\n

Equipado con venaci\u00f3n alar de una forma ef\u00edmera, el pecho y las alas de una lib\u00e9lula, y las patas de una mantis religiosa, estos insectos alados parecen un mosaico de diversos animales.<\/p>\n

Las larvas, sin embargo, son una reminiscencia de camarones de agua dulce. Su estilo de vida result\u00f3 ser un gran enigma<\/strong>: el modo de inserci\u00f3n y algunos de sus personajes sugieren claramente un h\u00e1bitat fluvial<\/strong>. Su singular anatom\u00eda indica, adem\u00e1s, que estos animales eran depredadores de emboscada que viven en un parte excavada en el lecho del r\u00edo<\/strong>.<\/p>\n

Tras estos descubrimientos, los cient\u00edficos suponen que las alas se originaron a partir de <\/strong>las placas tor\u00e1cicas posteriores, mientras que los genes de las piernas fueron reclutados para el control del desarrollo.<\/p>\n

En general, el excitante descubrimiento de Coxoplectoptera <\/strong>contribuye a una mejor comprensi\u00f3n de la evoluci\u00f3n de los insectos<\/p>\n

Informaci\u00f3n en otros medios de comunicaci\u00f3n<\/strong><\/span><\/p>\n

Cient\u00edficos alemanes descubren un nuevo orden de insectos del Cret\u00e1cico Inferior de Am\u00e9rica del Sur<\/a>. Los f\u00f3siles fueron nombrados Coxoplectoptera<\/strong> por sus descubridores y sus resultados fueron publicados en una edici\u00f3n especial sobre insectos.<\/p>\n

Los cient\u00edficos analizan en su art\u00edculo f\u00f3siles que se encontraron en finos sedimentos de Brasil de hace unos 120 millones de a\u00f1os<\/a><\/strong> <\/strong>unas larvas<\/strong> y ejemplares con alas que estaban muy bien conservados. Podr\u00edan ser parientes de especies que posteriormente se extinguieron, por lo que hoy no tendr\u00edan descendientes.<\/p>\n

Cap\u00edtulo de un Nuevo Libro de la Editorial Cambridge University Press<\/a><\/p>\n

Apterygota: primarily wingless insects<\/a><\/h3>\n

These announcements coincided with the commencement of a major increase in the commercial extraction of the Crato limestones or so-called pedra de larje<\/strong>. Today, specimens of Dastilbe can be purchased in fossil shops around the world or on the Internet, and the number of scienti<\/strong>\ufb01<\/strong>c papers describing Crato fossils is in the hundreds<\/strong>. From an initial faunal list of a single \ufb01sh and an unnamed may\ufb02y larva in the middle of the twentieth century, the faunal and <\/strong>\ufb02<\/strong>oral list today includes over 100 insect species, nine species of <\/strong>\ufb01<\/strong>sh and nearly a dozen arachnids. Turtles, lizards and even a bird are known<\/strong>, but among the vertebrates the formation is gaining prominence for the diversity and spectacular preservation of its pterosaurs<\/strong>. The Crato Formation has the most diverse fossil assemblage for any non-marine Cretaceous locality in Gondwana, and perhaps Laurasia too<\/strong>. Museum collections around the world are full of new species of Crato insects, plants and even pterosaurs just waiting to be described. This book brings together the various components of the palaeobiota and attempts to describe the ancient environment<\/strong>s represented by the formation. It is one of the clearest windows yet into the Mesozoic, and although its edges may still be misty, a picture of a Cretaceous low-latitude environment is becoming much, much clearer.<\/strong><\/p>\n

11.2 Apterygota: primarily wingless insects<\/a><\/strong><\/h3>\n

Arnold H. Staniczek and Gunter Bechly<\/p>\n

There are several small-taxa at the base of the Hexapoda lacking wings that formerly were referred to as \u2018Apterygota\u2019, until Hennig (1953) recognized its paraphyly with respect to the winged insects, the Pterygota<\/strong>. Usually \ufb01ve Recent higher taxa are recognized among apterygotes: Collembola <\/strong>(springtails), Protura, Diplura, Archaeognatha (bristletails) and Zygentoma (silver\ufb01sh and \ufb01rebrats), the former three often united as the Entognatha, as their mouthparts are enclosed within a gnathal pouch. Recently it has been proposed that Diplura are more closely related to the insects than to Protura and Collembola<\/strong> (Bitsch and Bitsch, 2000). It is generally accepted that Archaeognatha and Zygentoma have closer phylogenetic af<\/strong>\ufb01<\/strong>nities to the Pterygota than to the entognathous taxa<\/strong>. All of these taxa, however, share a number of plesiomorphic characters such as the retention of abdominal leglets and moulting even in the adult stage. In the Crato Formation, so far only one species each of Diplura (two specimens) and Zygentoma (two specimens) have been discovered (Figure 11.1; Plates 7a and b). The other orders are certainly to be expected in the Mesozoic of South America as well, but probably have a very low preservation potential due to a combination of their delicate anatomy, tiny size and cryptic lifestyle as soil-dwelling organisms<\/strong>.<\/p>\n

Order Diplura: diplurans<\/strong><\/p>\n

Diplura is a globally distributed taxon comprising about 850 recent species<\/strong>. They are generally classi\ufb01ed into two different lineages, the Campodeomorpha (Rhabdura) and Japygomorpha (Dicellurata), which have a rather different appearance. Campodeomorph diplurans have long slender legs that enable fast movement and high agility, whereas japygomorphs are better adapted for a life within soil interstices. While the campodeomorphs have \ufb01liform cerci consisting of <\/strong>many segments, the cerci of japygomorphs are transformed into unsegmented forceps. Both groups, however, are cryptozoic and con\ufb01ned to soil<\/strong>. Campodeiform diplurans are mostly omnivorous or herbivorous animals, which feed on a variety of plant matter, often rotten leaves<\/strong>. The japygomorphs are predominantly predators and feed on other soil-dwelling arthropods such as<\/strong> other entognathous <\/strong>insects, myriapods and mites<\/strong>. They generally catch their prey by grasping it with the abdominal forceps. All diplurans are small and soft-bodied hexapods of whitish colour that generally only reach a body size of a few millimetres, but some japygomorphs may achieve a larger body size, of up to 6 cm. The Campodeomorpha have long \ufb01liform antennae with up to 70 segments. As in all primarily apterous hexapods, all antennal segments are equipped with intrinsic muscles. The antennae of japygomorphs are comparably short and stout, and in some they even resemble a telescope<\/strong> with retractable segments. (\u2026) All Recent diplurans lack compound eyes, but<\/strong> the entire body is equipped with a variety of sensory hairs. Their abdomen is composed of 10 segments, the anterior seven bearing paired leglets and often also ventral eversible vesicles that are actively used to absorb water (\u2026)<\/p>\n

Most recent authors unite Diplura and Ellipura (Collembola+Protura) <\/strong>in the Entognatha (\u2026) Judging from their phylogenetic position as basal hexapods Diplura must have already originated by the Early Devonian, but unfortunately there are no fossils<\/strong> from this period that could shed light on their early evolution. The enigmatic Testajapyxthomasi from the Upper Carboniferous of Mazon Creek of Illinois (Kukalov\u00b4a-Peck, 1987) bears well-developed compound eyes, long maxillary and labial palps, and multi-articulated abdominal leglets. Its abdomen bears the typical forceps of the Rhabdura (\u2026)<\/p>\n

Referencia de La Publicaci\u00f3n<\/strong><\/p>\n

STANICZEK, A. & BECHLY, G. & GODUNKO, R.J.<\/strong>\u00a0(2011): Coxoplectoptera, a new fossil order of Palaeoptera (Arthropoda: Insecta), with comments on the phylogeny of the stem group of mayflies (Ephemeroptera). –\u00a0Insect Systematics & Evolution<\/em>,\u00a042<\/strong>: 101-138.<\/p>\n

Mysterious Fossils Provide New Clues to Insect Evolution<\/a><\/h3>\n

ScienceDaily (July 19, 2011) <\/strong><\/span>\u2014 Scientists at the Stuttgart Natural History Museum and colleagues have discovered a new insect order from the Lower Cretaceous of South America. The spectacular fossils were named Coxoplectoptera by their discoverers and their findings were published in a special issue on Cretaceous Insects in the scientific journal Insect Systematics & Evolution<\/strong>.<\/p>\n

\u00a0The work group led by Dr. Arnold H. Staniczek and Dr. G\u00fcnter Bechly, both experts on basal insects, determined that these fossils represent extinct relatives of modern mayflies. Coxoplectoptera, however, significantly differ from both mayflies and all other known insects in anatomy and mode of life<\/strong>. With the discovery of adult winged specimens and excellently preserved larvae<\/strong>, the scientists were able to clarify the phylogenetic position of these animals and presented a new hypothesis regarding the relationships of basal winged insects<\/strong>. Equipped with wing venation of a mayfly, breast and wing shape of a dragonfly, and legs of a praying mantis, these winged insects look like a patchwork of various animals. The peculiar larvae, however, are reminiscent of freshwater shrimps<\/strong>. Their lifestyle turned out to be a major enigma: their mode of embedding and certain other characteristics clearly suggest a fluvial habitat<\/strong>. Their unique anatomy indicates that these animals were ambush predators living partly dug in the river bed<\/strong>.<\/p>\n

These animals furthermore provided clues to the long-standing controversial debate of the evolutionary origin of the insect wing<\/strong>. The scientists presume that wings originated from thoracic backplates, while leg genes were recruited for their developmental control.<\/p>\n","protected":false},"excerpt":{"rendered":"

Me encontraba leyendo una noticia sobre el origen de los insectos alados cuando detect\u00e9 que se hablaba de \u201cexcavaciones en el lecho de un r\u00edo\u201d. Sabiendo sobradamente que el suelo es un recurso natural que se les atraganta a los periodistas y colegas de otras disciplinas (alg\u00fan\u00a0 d\u00eda \u201cmorder\u00e1n el polvo\u201d) me puse yo tambi\u00e9n a \u201cexcavar en el ciberespacio\u201d. Y, como era de esperar, me top\u00e9 con el suelo, en principio del Cret\u00e1cico y despu\u00e9s, retrocediendo en el tiempo, hasta el Dev\u00f3nico. Eso s\u00ed, todo el material recopilado es muy difuso en este asunto. Ahora bien, si he entendido\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[596,607,617],"tags":[47085,9213,47086],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/139893"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=139893"}],"version-history":[{"count":7,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/139893\/revisions"}],"predecessor-version":[{"id":140991,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/139893\/revisions\/140991"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=139893"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=139893"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=139893"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}