{"id":1656,"date":"2023-11-24T00:23:39","date_gmt":"2023-11-23T23:23:39","guid":{"rendered":"https:\/\/www.zahadyazajimavosti.cz\/?p=1656"},"modified":"2023-12-10T03:39:47","modified_gmt":"2023-12-10T02:39:47","slug":"proc-vyhynuli-dinosauri","status":"publish","type":"post","link":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/2023\/11\/24\/proc-vyhynuli-dinosauri\/","title":{"rendered":"Pro\u010d vyhynuli dinosau\u0159i?"},"content":{"rendered":"

10 nej\u00fa\u017easn\u011bj\u0161\u00edch hypot\u00e9z o tom, pro\u010d dinosau\u0159i zmizeli<\/strong> Sn\u011bdli sami sebe nebo je zni\u010dili mimozem\u0161\u0165an\u00e9?<\/p>\n

Ob\u0159\u00ed dinosau\u0159i ovl\u00e1dali planetu neuv\u011b\u0159iteln\u011b dlouhou dobu, a p\u0159\u00ed\u010diny jejich smrti jsou st\u00e1le zahaleny tajemstv\u00edm.<\/p>\n

Hypot\u00e9z je ale mnoho. Ne v\u0161echny vydr\u017e\u00ed kritiku.<\/p>\n

Jedna z nejnov\u011bj\u0161\u00edch verz\u00ed, nap\u0159\u00edklad tvrd\u00ed, \u017ee dinosaury zahubili mot\u00fdli…<\/p>\n

Zem\u0159eli hlady<\/strong><\/p>\n

N\u00e1hle se rozmno\u017eily \u017erav\u00e9 housenky, kter\u00e9 zp\u016fsobily nedostatek j\u00eddla dinosaur\u016f, – \u0159\u00edk\u00e1 americk\u00fd paleontolog, v\u00fdzkumn\u00fd pracovn\u00edk muzea st\u00e1tu New Jersey, kde jsou ulo\u017eeny kosti dinosaur\u016f, Brian Switek. (1)<\/p>\n

V d\u016fsledku toho vyhynuli dinosau\u0159i d\u00edky ban\u00e1ln\u00edmu d\u016fvodu: od hladu.<\/p>\n

Podle Switeka, p\u0159ed 66 a\u017e 65 mili\u00f3ny lety byla Zem\u011b podobn\u00e1 obrovsk\u00e9 kv\u011btinov\u00e9 zahrad\u011b.<\/p>\n

Pt\u00e1ci je\u0161t\u011b neexistovali, a proto mot\u00fdli l\u00e9tali a mno\u017eili se bez z\u00e1bran.<\/p>\n

A housenky se p\u0159ed p\u0159em\u011bnou v mot\u00fdly \u017eivili v\u00fdhradn\u011b rostlinami – hlavn\u00ed potravou b\u00fdlo\u017erav\u00fdch dinosaur\u016f.<\/p>\n

Nespo\u010detn\u00e9 arm\u00e1dy mot\u00fdl\u016f a housenek se\u017erali obrovsk\u00e9 rozlohy zelen\u011b.<\/p>\n

A \u010d\u00edm m\u00e9n\u011b bylo b\u00fdlo\u017erav\u00fdch dinosaur\u016f, t\u00edm hladov\u011bj\u0161\u00ed byli maso\u017erav\u00ed dravci. Tak\u017ee postupn\u011b vym\u0159eli v\u0161ichni.<\/p>\n

Sn\u011bden\u00e1 vejce<\/strong><\/p>\n

Paleontolog George Wieland (2) z univerzity v Yale na po\u010d\u00e1tku XX. stolet\u00ed tvrdil, \u017ee dinosau\u0159i jedli sami sebe, a tak se odsoudili k z\u00e1niku.<\/p>\n

Podle n\u011bj p\u0159edkov\u00e9 stra\u0161n\u00fdch tyranosaur\u016f pravd\u011bpodobn\u011b ud\u011blali sv\u016fj prvn\u00ed krok sm\u011brem ke gigantismu, kdy\u017e za\u010dali j\u00edst vejce Sauropod\u016f.<\/p>\n

Dokonce ani pe\u010duj\u00edc\u00ed dinosau\u0159\u00ed matky dinosaur\u016f nemohly zabr\u00e1nit pytla\u010den\u00ed hladov\u00fdch pred\u00e1tor\u016f.<\/p>\n

Deformace sko\u0159\u00e1pky<\/strong><\/p>\n

Expert na fosiln\u00ed bezobratl\u00e9 G. K. Erben a jeho kolegov\u00e9 tak\u00e9 v\u011b\u0159ili, \u017ee vejce p\u0159isp\u011bly k z\u00e1niku dinosaur\u016f. Ale jinak, ne\u017e je pops\u00e1no v p\u0159edchoz\u00ed kapitole.<\/p>\n

V \u010dasopise v roce 1979 v\u00fdzkumn\u00edci zve\u0159ejnili verzi o tom, \u017ee anal\u00fdza zkamen\u011bl\u00fdch zbytk\u016f sko\u0159\u00e1pek, nalezen\u00fdch v ji\u017en\u00ed Francii a ve \u0161pan\u011blsk\u00fdch Pyrenej\u00edch, uk\u00e1zala dva typy odchylek: sko\u0159\u00e1pky n\u011bkter\u00fdch vajec byly vrstven\u00e9 a tlust\u00e9, a druh\u00e9 – velmi tenk\u00e9.<\/p>\n

Ka\u017ed\u00e1 z t\u011bchto situac\u00ed byla fat\u00e1ln\u00ed: v\u00edcevrstv\u00e1 sko\u0159\u00e1pka dusila embrya a vejce s tenkou sko\u0159\u00e1pkou mohlo snadno prasknout a zp\u016fsobit dehydrataci embrya nebo se st\u00e1t snadnou ko\u0159ist\u00ed pro pred\u00e1tory.<\/p>\n

Hyperaktivn\u00ed \u017el\u00e1zy<\/strong><\/p>\n

Paleontolog Franz Nopcsa von Fels\u0151-Szilv\u00e1s (1877\u20131933) na po\u010d\u00e1tku XX. stolet\u00ed navrhl, \u017ee dinosau\u0159i vyrostli do gigantick\u00fdch rozm\u011br\u016f kv\u016fli poru\u0161e hypof\u00fdzy. (3)<\/p>\n

\u017dl\u00e1zy byly p\u0159\u00ed\u010dinou toho, \u017ee se zv\u00ed\u0159ata stala patologicky obrovsk\u00e1 a groteskn\u00ed.<\/p>\n

Nopcsa se pokusil propojit lidsk\u00e9 patologie s vyhynut\u00edm dinosaur\u016f, ale nen\u00ed \u017e\u00e1dn\u00fd spolehliv\u00fd d\u016fkaz o tom, \u017ee hypof\u00fdza by mohla m\u00edt dopad na rozsah a z\u00e1nik dinosaur\u016f.<\/p>\n

Evolu\u010dn\u00ed sebezni\u010den\u00ed<\/strong><\/p>\n

Existuje teorie, \u017ee n\u011bkter\u00e9 druhy \u017eiv\u00fdch bytost\u00ed „jdou cestou dinosaur\u016f“ – jin\u00fdmi slovy, v pr\u016fb\u011bhu evoluce jsou p\u0159\u00edli\u0161 pomal\u00ed, hloup\u00ed, nebo mal\u00ed, ne\u017e aby p\u0159e\u017eili.<\/p>\n

Jist\u00fd \u010das se paleontologov\u00e9 domn\u00edvali, \u017ee to sam\u00e9 se stalo s dinosaury.<\/p>\n

P\u0159\u00edli\u0161 mnoho samc\u016f<\/strong><\/p>\n

B\u011bhem posledn\u00edho desetilet\u00ed specialista na neplodnost Sherman Silber opakovan\u011b prohla\u0161oval, \u017ee dinosau\u0159i vyhynuli, proto\u017ee nemohli naj\u00edt partnera.<\/p>\n

Silber navrhl, \u017ee, obdobn\u011b jako u dne\u0161n\u00edch alig\u00e1tor\u016f a krokod\u00fdl\u016f, mohly venkovn\u00ed teplotn\u00ed zm\u011bny zm\u011bnit pohlav\u00ed embry\u00ed dinosaur\u016f b\u011bhem v\u00fdvoje ve vejc\u00edch.<\/p>\n

V tomto p\u0159\u00edpad\u011b by zm\u011bna klimatu, zp\u016fsoben\u00e1 vulkanickou aktivitou a dopadem asteroidu mohla b\u00fdt d\u016fvodem, \u017ee z drtiv\u00e9 v\u011bt\u0161iny vajec se vyl\u00edhly sam\u00ed samci.<\/p>\n

St\u00e1le v\u0161ak nev\u00edme, zda teplota mohla m\u00edt vliv na v\u00fdvoj pohlav\u00ed dinosaur\u016f nebo ne.<\/p>\n

\u0160ed\u00fd z\u00e1kal<\/strong><\/p>\n

V roce 1982 oftalmolog L.R. Croft navrhl, \u017ee p\u0159\u00ed\u010dinou vyhynut\u00ed dinosaur\u016f byl jejich \u0161patn\u00fd zrak. (4)<\/p>\n

P\u0159i del\u0161\u00edm p\u016fsoben\u00ed tepla se \u0161ed\u00fd z\u00e1kal vyv\u00edj\u00ed rychleji a Croft z toho vyvodil z\u00e1v\u011br, \u017ee dinosau\u0159i s rohy a h\u0159ebeny na hlav\u011b pou\u017eili tyto „dekorace“ pro ochranu p\u0159ed nemilosrdn\u00fdm sluncem druhohor.<\/p>\n

Nicm\u00e9n\u011b ani to nezachr\u00e1nilo o\u010di dinosaur\u016f, a\u017e nakonec ztratili zrak do doby pohlavn\u00ed zralosti.<\/p>\n

Supernova<\/strong><\/p>\n

V roce 1971 fyzik Wallace Tucker (5) a paleontolog Dale Russell (6) navrhli, \u017ee exploze supernovy pom\u011brn\u011b bl\u00edzko Slune\u010dn\u00ed soustavy na konci k\u0159\u00eddov\u00e9ho obdob\u00ed mohla m\u00edt katastrof\u00e1ln\u00ed d\u016fsledky pro \u017eivot na Zemi.<\/p>\n

V\u00fdbuch supernovy by zaplavil atmosf\u00e9ru planetu \u00fa\u010dink\u016fm rentgenov\u00fdch paprsk\u016f nebo jin\u00fdch druh\u016f z\u00e1\u0159en\u00ed, co\u017e by vedlo k rychl\u00e9 zm\u011bn\u011b klimatu a teplota na Zemi by rychle klesla. Jen\u017ee \u017e\u00e1dn\u00fd d\u016fkaz o t\u00e9to ud\u00e1losti nebyl nalezen.<\/p>\n

Mimozem\u0161\u0165an\u00e9<\/strong><\/p>\n

V\u00fdstava v Muzeu prav\u011bku v\u00fdchodn\u00edho Utahu (7) ukazuje, \u017ee mimozem\u0161\u0165an\u00e9 nemohli zni\u010dit dinosaury, u\u017e jen proto, \u017ee se nezachovaly \u017e\u00e1dn\u00e9 fosilie ani mimozem\u0161\u0165an\u016f ani stopy po jejich \u010dinnosti.<\/p>\n

Nicm\u00e9n\u011b, nedostatek d\u016fkaz\u016f nezastavil n\u011bkter\u00e9 badatele od vytv\u00e1\u0159en\u00ed dal\u0161\u00edch sc\u00e9n\u00e1\u0159\u016f takov\u00e9 katastrofy.<\/p>\n

Prdy<\/strong><\/p>\n

Dal\u0161\u00ed hypot\u00e9za je, \u017ee dinosaury odsoudily k z\u00e1niku jejich vlastn\u00ed prdy.<\/p>\n

V lo\u0148sk\u00e9m roce se paleontolog David Wilkinson a jeho kolegov\u00e9 pokusili spo\u010d\u00edtat, kolik plynu metanu mohl vyprodukovat obrovsk\u00fd Sauropod s dlouh\u00fdm krkem.<\/p>\n

V\u00fdzkumn\u00edci nazna\u010dili, \u017ee dinosau\u0159i mohli produkc\u00ed metanu ovlivnit glob\u00e1ln\u00ed klima. (8)<\/p>\n

Ale nakonec, r\u016fzn\u00ed sauropodi \u017eili na Zemi po des\u00edtky milion\u016f let, a nevykazovali \u017e\u00e1dn\u00e9 zn\u00e1mky otravy plynem.<\/p>\n

I kdy\u017e nev\u011bnovali pozornost dal\u0161\u00edm studi\u00edm, Wilkinson a jeho kolegov\u00e9 shroma\u017e\u010fovali d\u016fkazy na toto t\u00e9ma na tematick\u00fdch webech a dlouho prokazovali spr\u00e1vnost sv\u00e9 teorie.<\/p>\n

Odkazy<\/strong><\/em><\/p>\n

(1) http:\/\/brianswitek.com\/<\/a> <\/em>
\n(2) Wieland, G. 1925. Dinosaur Extinction. American Naturalist. 59 (665): 557-565<\/em>
\n(3) http:\/\/cs.wikipedia.org\/wiki\/Franz_Nopcsa<\/a> <\/em>
\n(4) http:\/\/trove.nla.gov.au\/work\/25939711?selectedversion=NBD2222881<\/a> <\/em>
\n(5) http:\/\/en.wikipedia.org\/wiki\/Wallace_Hampton_Tucker<\/a> <\/em>
\n(6) http:\/\/en.wikipedia.org\/wiki\/Dale_Russell<\/a><\/em>
\n(7) http:\/\/usueastern.edu\/museum\/<\/a> <\/em>
\n(8) http:\/\/wamc.org\/post\/dr-david-wilkinson-liverpool-john-moores-university-dinosaurs-and-methane<\/a><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

10 nej\u00fa\u017easn\u011bj\u0161\u00edch hypot\u00e9z o tom, pro\u010d dinosau\u0159i zmizeli<\/p>\n","protected":false},"author":1,"featured_media":1155,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17,19],"tags":[29],"class_list":["post-1656","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-veda","category-zahady","tag-zivocichove"],"_links":{"self":[{"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/posts\/1656","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/comments?post=1656"}],"version-history":[{"count":1,"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/posts\/1656\/revisions"}],"predecessor-version":[{"id":1657,"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/posts\/1656\/revisions\/1657"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/media\/1155"}],"wp:attachment":[{"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/media?parent=1656"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/categories?post=1656"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zahadyazajimavosti.cz\/index.php\/wp-json\/wp\/v2\/tags?post=1656"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}