{"id":1470,"date":"2026-06-04T11:23:02","date_gmt":"2026-06-04T17:23:02","guid":{"rendered":"https:\/\/elcontemporaneo.mx\/?p=1470"},"modified":"2026-06-04T12:02:28","modified_gmt":"2026-06-04T18:02:28","slug":"el-huevo-antes-de-la-gallina","status":"publish","type":"post","link":"https:\/\/elcontemporaneo.mx\/index.php\/2026\/06\/04\/el-huevo-antes-de-la-gallina\/","title":{"rendered":"El huevo antes de la gallina"},"content":{"rendered":"

Ya les platiqu\u00e9 un poco de los linajes de anfibios que comenzaron la colonizaci\u00f3n de la superficie, adentr\u00e1ndose cada vez m\u00e1s en tierra firme y llegando a alcanzar proporciones enormes en algunos grupos.<\/span><\/p>\n

La \u00fanica barrera que deten\u00eda su conquista definitiva de todos los ambientes terrestres era el requisito indispensable del medio acu\u00e1tico para su desarrollo larvario, una cadena que ser\u00eda destruida unos cuantos millones de a\u00f1os despu\u00e9s.<\/span><\/p>\n

Un linaje de anfibios evolucion\u00f3 hacia un estilo de vida capaz de abandonar por completo el agua (m\u00e1s que para beber), siendo los primeros vertebrados que pudieron dejar sus embriones en tierra firme sin necesidad de tener fuentes de agua para su desarrollo: fabricaron un microambiente acuoso privado, perfectamente estructurado, con su raci\u00f3n de nutrientes y todo protegido con membranas que evitan la desecaci\u00f3n, promueven la oxigenaci\u00f3n, y una elegante c\u00e1scara exterior de calcio que es resistente y abre-f\u00e1cil a la vez, para cuando las cr\u00edas est\u00e1n suficientemente maduras para explorar el mundo exterior.<\/span><\/p>\n

La evoluci\u00f3n del huevo amniota, que surgi\u00f3 hace unos 325 millones de a\u00f1os y much\u00edsimo antes que la primera gallina, junto con una piel seca recubierta de escamas queratinizadas que evita la deshidrataci\u00f3n, respiraci\u00f3n enteramente pulmonar y el desarrollo de una fecundaci\u00f3n interna les dio a estos tetr\u00e1podos el empujoncito que hac\u00eda falta para poder convertirse en amos y se\u00f1ores del supercontinente Pangea.\u00a0<\/span><\/p>\n

As\u00ed, los Amniotas derivaron en dos l\u00edneas evolutivas: los Sin\u00e1psidos y los Saur\u00f3psidos.<\/span><\/p>\n

Esta divisi\u00f3n se inici\u00f3 en el Carbon\u00edfero y durante el P\u00e9rmico ambos grupos se diversificaron y prosperaron siendo los sin\u00e1psidos (llamados tradicionalmente \u201creptiles mamiferoides\u201d) quienes obtuvieron\u00a0 primero la ventaja.<\/span><\/p>\n

Les hablar\u00e9 de cada uno a su debido tiempo.<\/span><\/p>\n

S\u00edgueme por: https:\/\/www.facebook.com\/DinodatosFB<\/a><\/p>\n

*Infograf\u00eda: El Contempor\u00e1neo | Dise\u00f1o editorial realizado con apoyo de inteligencia artificial (ChatGPT\/OpenAI), basado en informaci\u00f3n de este art\u00edculo de Dinodatos.<\/strong><\/em><\/p>\n

\"\"<\/p>\n","protected":false},"excerpt":{"rendered":"

Ya les platiqu\u00e9 un poco de los linajes de anfibios que comenzaron la colonizaci\u00f3n de la superficie, adentr\u00e1ndose cada vez m\u00e1s en tierra firme y llegando a alcanzar proporciones enormes en algunos grupos. La \u00fanica barrera que deten\u00eda su conquista definitiva de todos los ambientes terrestres era el requisito indispensable del medio acu\u00e1tico para su […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[13],"tags":[],"columnista":[17],"class_list":["post-1470","post","type-post","status-publish","format-standard","hentry","category-columnas","columnista-dinodatos"],"_links":{"self":[{"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/posts\/1470","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/comments?post=1470"}],"version-history":[{"count":6,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/posts\/1470\/revisions"}],"predecessor-version":[{"id":1478,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/posts\/1470\/revisions\/1478"}],"wp:attachment":[{"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/media?parent=1470"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/categories?post=1470"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/tags?post=1470"},{"taxonomy":"columnista","embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/columnista?post=1470"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}