{"id":136130,"date":"2013-02-01T08:00:11","date_gmt":"2013-02-01T06:00:11","guid":{"rendered":"http:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/?p=136130"},"modified":"2013-03-26T12:06:12","modified_gmt":"2013-03-26T10:06:12","slug":"un-ejemplo-de-reversion-en-las-palomas-en-el-parrafo-ducentesimo-trigesimo-quinto-de-el-origen-de-las-especies","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/2013\/02\/01\/136130","title":{"rendered":"Un ejemplo de reversi\u00f3n en las palomas en el p\u00e1rrafo ducent\u00e9simo trig\u00e9simo quinto de El Origen de las Especies"},"content":{"rendered":"<p><img decoding=\"async\" class=\"alignnone\" src=\"http:\/\/4.bp.blogspot.com\/_t07Jvq6-ehg\/SvJ5ltIRc1I\/AAAAAAAATx4\/7BKt9YJMLUU\/s320\/DERBYS.jpg\" alt=\"\" width=\"320\" height=\"194\" \/><\/p>\n<p>El autor presenta en este p\u00e1rrafo un buen ejemplo de reversi\u00f3n. Nada que pueda servir a sostener la falacia de la selecci\u00f3n natural como teor\u00eda cient\u00edfica. Ni tampoco ayuda alguna para comprender el Origen de la variaci\u00f3n, sino m\u00e1s bien al contrario\u2026\u2026<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>235<\/p>\n<p style=\"text-align: justify;\"><em>With pigeons, however, we have another case, namely, the occasional appearance in all the breeds, of slaty-blue birds with two black bars on the wings, white loins, a bar at the end of the tail, with the outer feathers externally edged near their bases with white. As all these marks are characteristic of the parent rock-pigeon, I presume that no one will doubt that this is a case of reversion, and not of a new yet analogous variation appearing in the several breeds. We may, I think, confidently come to this conclusion, because, as we have seen, these coloured marks are eminently liable to appear in the crossed offspring of two distinct and differently coloured breeds; and in this case there is nothing in the external conditions of life to cause the reappearance of the slaty-blue, with the several marks, beyond the influence of the mere act of crossing on the laws of inheritance.<\/em><\/p>\n<p style=\"text-align: justify;\"><em>\u00a0<\/em><\/p>\n<p style=\"text-align: justify;\"><em>En las palomas tambi\u00e9n tenemos otro caso: el de la aparici\u00f3n accidental, en todas las razas, de individuos de color azul de pizarra, con dos fajas negras en las alas, con la parte posterior del lomo blanca, una faja en el extremo de la cola, y las plumas exteriores de \u00e9sta orladas exteriormente de blanco junto a su arranque. Como todas estas se\u00f1ales son caracter\u00edsticas de la paloma silvestre progenitora, creo que nadie dudar\u00e1 de que \u00e9ste es un caso de reversi\u00f3n y no de una nueva variaci\u00f3n an\u00e1loga que aparece en diferentes castas. Creo que podemos llegar confiadamente a esta conclusi\u00f3n, porque hemos visto que estos caracteres de color propenden mucho a aparecer en la descendencia cruzada de dos razas distintas y de coloraciones diferentes; y en este caso, aparte de la influencia del simple hecho del cruzamiento sobre las leyes de la herencia, nada hay en las condiciones externas de vida que motive la reaparici\u00f3n del color azul de pizarra con las vanas se\u00f1ales.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>El autor presenta en este p\u00e1rrafo un buen ejemplo de reversi\u00f3n. Nada que pueda servir a sostener la falacia de la selecci\u00f3n natural como teor\u00eda cient\u00edfica. Ni tampoco ayuda alguna para comprender el Origen de la variaci\u00f3n, sino m\u00e1s bien al contrario\u2026\u2026 &nbsp; &nbsp; &nbsp; 235 With pigeons, however, we have another case, namely, the occasional appearance in all the breeds, of slaty-blue birds with two black bars on the wings, white loins, a bar at the end of the tail, with the outer feathers externally edged near their bases with white. As all these marks are characteristic of the\u2026<\/p>\n","protected":false},"author":86,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[467,14322],"tags":[],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/posts\/136130"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/users\/86"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/comments?post=136130"}],"version-history":[{"count":3,"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/posts\/136130\/revisions"}],"predecessor-version":[{"id":136586,"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/posts\/136130\/revisions\/136586"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/media?parent=136130"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/categories?post=136130"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/biologia_pensamiento\/wp-json\/wp\/v2\/tags?post=136130"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}