{"id":355,"date":"2024-06-20T05:08:20","date_gmt":"2024-06-20T05:08:20","guid":{"rendered":"https:\/\/www.lifescienceart.com\/?p=355"},"modified":"2024-06-20T05:08:20","modified_gmt":"2024-06-20T05:08:20","slug":"alligators-breathe-like-birds-the-evolutionary-significance-of-unidirectional-breathing","status":"publish","type":"post","link":"https:\/\/www.lifescienceart.com\/cs\/science\/zoology\/alligators-breathe-like-birds-the-evolutionary-significance-of-unidirectional-breathing\/","title":{"rendered":"Alig\u00e1to\u0159i d\u00fdchaj\u00ed jako pt\u00e1ci: Jedine\u010dn\u00e1 d\u00fdchac\u00ed adaptace, kter\u00e1 zm\u011bnila jejich osud"},"content":{"rendered":"

Alig\u00e1to\u0159i d\u00fdchaj\u00ed jako pt\u00e1ci: Jedine\u010dn\u00e1 respira\u010dn\u00ed adaptace<\/h2>\n\n

Odhalen\u00ed tajemstv\u00ed d\u00fdch\u00e1n\u00ed alig\u00e1tor\u016f<\/h2>\n\n

Po stalet\u00ed byli v\u011bdci fascinov\u00e1ni pozoruhodn\u00fdmi podobnostmi a rozd\u00edly mezi pt\u00e1ky a alig\u00e1tory, dv\u011bma zd\u00e1nliv\u011b odli\u0161n\u00fdmi tvory. Zat\u00edmco pt\u00e1ci se vzn\u00e1\u0161ej\u00ed po obloze se sv\u00fdmi ope\u0159en\u00fdmi k\u0159\u00eddly, alig\u00e1to\u0159i \u010d\u00edhaj\u00ed v ba\u017ein\u00e1ch a \u0159ek\u00e1ch, jejich obrn\u011bn\u00e1 t\u011bla a siln\u00e9 \u010delisti sv\u011bd\u010d\u00ed o jejich d\u00e1vn\u00e9m rodokmenu. Navzdory sv\u00e9mu kontrastn\u00edmu vzhledu sd\u00edlej\u00ed pt\u00e1ci i alig\u00e1to\u0159i spole\u010dn\u00e9ho p\u0159edka jako archosau\u0159i, skupinu \u201evl\u00e1dnouc\u00edch plaz\u016f\u201c, kte\u0159\u00ed kdysi ovl\u00e1dali Zemi.<\/p>\n\n

Jedn\u00edm z nejzaj\u00edmav\u011bj\u0161\u00edch objev\u016f o archosaurech je jejich jedine\u010dn\u00fd d\u00fdchac\u00ed syst\u00e9m, kter\u00fd jim umo\u017e\u0148uje d\u00fdchat zp\u016fsobem, kter\u00fd se li\u0161\u00ed od savc\u016f. Pt\u00e1ci maj\u00ed nap\u0159\u00edklad vysoce \u00fa\u010dinn\u00fd d\u00fdchac\u00ed syst\u00e9m p\u0159izp\u016fsoben\u00fd jednosm\u011brn\u00e9mu proud\u011bn\u00ed vzduchu, co\u017e znamen\u00e1, \u017ee vzduch proud\u00ed jedn\u00edm sm\u011brem p\u0159es jejich pl\u00edce v nep\u0159etr\u017eit\u00e9m okruhu. Tento syst\u00e9m umo\u017e\u0148uje pt\u00e1k\u016fm extrahovat kysl\u00edk ze vzduchu efektivn\u011bji ne\u017e savci.<\/p>\n\n

Alig\u00e1to\u0159i: Tak\u00e9 jednosm\u011brn\u00ed d\u00fdcha\u010di<\/h2>\n\n

Po dlouhou dobu v\u011bdci p\u0159edpokl\u00e1dali, \u017ee alig\u00e1to\u0159i mohou tak\u00e9 d\u00fdchat prost\u0159ednictv\u00edm jednosm\u011brn\u00e9ho proud\u011bn\u00ed vzduchu, ale chyb\u011bly pr\u016fkazn\u00e9 d\u016fkazy. Ned\u00e1vn\u00fd v\u00fdzkum v\u0161ak potvrdil, \u017ee alig\u00e1to\u0159i skute\u010dn\u011b tuto pozoruhodnou respira\u010dn\u00ed adaptaci maj\u00ed.<\/p>\n\n

Aby tuto hypot\u00e9zu prozkoumali, um\u00edstili v\u011bdci senzory do d\u00fdchac\u00edch cest mrtv\u00fdch alig\u00e1tor\u016f a um\u011ble ventilovali jejich pl\u00edce. V\u00fdsledky uk\u00e1zaly, \u017ee vzduch m\u016f\u017ee proudit jednosm\u011brn\u011b p\u0159es okruh cest v d\u00fdchac\u00ed soustav\u011b alig\u00e1tora.<\/p>\n\n

Aby sv\u00e9 n\u00e1lezy d\u00e1le potvrdili, um\u00edstili v\u011bdci za\u0159\u00edzen\u00ed pro m\u011b\u0159en\u00ed pr\u016ftoku vzduchu do \u017eiv\u00fdch alig\u00e1tor\u016f. Zjistili, \u017ee pr\u016ftok vzduchu v d\u00fdchac\u00edch soustav\u00e1ch alig\u00e1tor\u016f pokra\u010doval nep\u0159etr\u017eit\u011b jak p\u0159i n\u00e1dechu, tak p\u0159i v\u00fddechu, co\u017e poskytuje siln\u00fd d\u016fkaz pro jednosm\u011brn\u00e9 d\u00fdch\u00e1n\u00ed.<\/p>\n\n

Evolu\u010dn\u00ed v\u00fdznam jednosm\u011brn\u00e9ho d\u00fdch\u00e1n\u00ed<\/h2>\n\n

Objev, \u017ee alig\u00e1to\u0159i mohou d\u00fdchat jako pt\u00e1ci, m\u00e1 v\u00fdznamn\u00e9 d\u016fsledky pro na\u0161e ch\u00e1p\u00e1n\u00ed evoluce archosaur\u016f. Pokud \u017eiv\u00ed alig\u00e1to\u0159i a pt\u00e1ci sd\u00edlej\u00ed tento fyziologick\u00fd mechanismus, je pravd\u011bpodobn\u00e9, \u017ee i posledn\u00ed spole\u010dn\u00fd p\u0159edek dinosaur\u016f a alig\u00e1tor\u016f m\u011bl jednosm\u011brn\u00e9 d\u00fdch\u00e1n\u00ed.<\/p>\n\n

Tato hypot\u00e9za nazna\u010duje, \u017ee jednosm\u011brn\u00e9 d\u00fdch\u00e1n\u00ed se vyvinulo u prvn\u00edch archosaur\u016f p\u0159ed v\u00edce ne\u017e 230 miliony let, po masov\u00e9m vym\u00edr\u00e1n\u00ed na konci permu a triasu, jedn\u00e9 z nejni\u010div\u011bj\u0161\u00edch ud\u00e1lost\u00ed v historii Zem\u011b.<\/p>\n\n

Jednosm\u011brn\u00e9 d\u00fdch\u00e1n\u00ed: V\u00fdhoda b\u011bhem masov\u00e9ho vym\u00edr\u00e1n\u00ed<\/h2>\n\n

Masov\u00e9 vym\u00edr\u00e1n\u00ed na konci permu a triasu vyhladilo p\u0159ibli\u017en\u011b 96 % mo\u0159sk\u00fdch druh\u016f a v\u00edce ne\u017e 70 % suchozemsk\u00fdch druh\u016f. Mezi p\u0159e\u017eiv\u0161\u00edmi byli ran\u00ed archosau\u0159i (nebo jejich bl\u00edzc\u00ed p\u0159edci) a jejich schopnost d\u00fdchat jednosm\u011brn\u011b jim mohla poskytnout konkuren\u010dn\u00ed v\u00fdhodu.<\/p>\n\n

Jednosm\u011brn\u00e9 d\u00fdch\u00e1n\u00ed je \u00fa\u010dinn\u011bj\u0161\u00ed zp\u016fsob z\u00edsk\u00e1v\u00e1n\u00ed kysl\u00edku ze vzduchu ne\u017e d\u00fdchac\u00ed syst\u00e9m savc\u016f. Pokud bylo masov\u00e9 vym\u00edr\u00e1n\u00ed na konci permu a triasu zp\u016fsobeno velk\u00fdmi zm\u011bnami v atmosf\u00e9\u0159e, jako je vy\u010derp\u00e1n\u00ed kysl\u00edku, mohli archosau\u0159i s jednosm\u011brn\u00fdm d\u00fdch\u00e1n\u00edm l\u00e9pe p\u0159e\u017e\u00edt ne\u017e jejich sou\u010dasn\u00edci savci.<\/p>\n\n

Vzestup archosaur\u016f<\/h2>\n\n

Vzestup archosaur\u016f k dominanci v d\u016fsledku masov\u00e9ho vym\u00edr\u00e1n\u00ed na konci permu a triasu lze potenci\u00e1ln\u011b p\u0159ipsat jejich jedine\u010dn\u00e9 respira\u010dn\u00ed adaptaci. Jednosm\u011brn\u00e9 d\u00fdch\u00e1n\u00ed jim mohlo poskytnout fyziologickou v\u00fdhodu, kter\u00e1 jim umo\u017enila p\u0159ekonat jin\u00e9 druhy a etablovat se jako dominantn\u00ed suchozem\u0161t\u00ed obratlovci po miliony let.<\/p>\n\n

Dal\u0161\u00ed v\u00fdzkum a d\u016fsledky<\/h2>\n\n

Zat\u00edmco objev jednosm\u011brn\u00e9ho d\u00fdch\u00e1n\u00ed u alig\u00e1tor\u016f je velk\u00fdm pr\u016flomem, je t\u0159eba dal\u0161\u00edho v\u00fdzkumu, abychom pln\u011b porozum\u011bli mechanism\u016fm a evolu\u010dn\u00edmu v\u00fdznamu t\u00e9to adaptace. Studium d\u00fdchac\u00edch syst\u00e9m\u016f jin\u00fdch archosaur\u016f, jak \u017eiv\u00fdch, tak vyhynul\u00fdch, pom\u016f\u017ee v\u011bdc\u016fm z\u00edskat hlub\u0161\u00ed porozum\u011bn\u00ed evoluce tohoto pozoruhodn\u00e9ho d\u00fdchac\u00edho syst\u00e9mu a jeho vlivu na historii \u017eivota na Zemi.<\/p>","protected":false},"excerpt":{"rendered":"

Alig\u00e1to\u0159i d\u00fdchaj\u00ed jako pt\u00e1ci: Jedine\u010dn\u00e1 respira\u010dn\u00ed adaptace Odhalen\u00ed tajemstv\u00ed d\u00fdch\u00e1n\u00ed alig\u00e1tor\u016f Po stalet\u00ed byli v\u011bdci fascinov\u00e1ni pozoruhodn\u00fdmi podobnostmi a rozd\u00edly mezi pt\u00e1ky a alig\u00e1tory, dv\u011bma zd\u00e1nliv\u011b odli\u0161n\u00fdmi tvory. Zat\u00edmco pt\u00e1ci…<\/p>\n","protected":false},"author":1,"featured_media":23697,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[280],"tags":[929,933,931,932,934,930],"class_list":["post-355","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-zoology","tag-alligators","tag-archosaurs","tag-respiration","tag-unidirectional-airflow","tag-permian-triassic-mass-extinction","tag-birds"],"_links":{"self":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/355","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/comments?post=355"}],"version-history":[{"count":1,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/355\/revisions"}],"predecessor-version":[{"id":356,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/355\/revisions\/356"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media\/23697"}],"wp:attachment":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media?parent=355"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/categories?post=355"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/tags?post=355"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}