Skryt\u00e9 ekosyst\u00e9my a\u00a0pravek\u00e9 DNA dokazuj\u00fa, \u017ee Antarkt\u00edda st\u00e1le patr\u00ed medzi najmenej presk\u00faman\u00e9 kontinenty.<\/p>\n
Ak sa niekedy pok\u00fa\u0161ame uchopi\u0165 koncept \u010dasu, netrv\u00e1 dlho, k\u00fdm n\u00e1s z\u00a0toho za\u010dne bolie\u0165 hlava. Hist\u00f3ria \u013eudstva je pritom v\u00a0porovnan\u00ed so vznikom \u017eivota na na\u0161ej plan\u00e9te zanedbate\u013ene kr\u00e1tka. Predstava, \u017ee sa vedcom podarilo objavi\u0165 DNA vzorku star\u00fa mili\u00f3n rokov<\/strong> takmer siaha za hranicu n\u00e1\u0161ho ch\u00e1pania. N\u00e1lez v\u0161ak m\u00f4\u017ee otvori\u0165 cestu k \u0161t\u00fadiu dlhodob\u00fdch reakci\u00ed oce\u00e1nskych ekosyst\u00e9mov na v\u00fdvoj klimatickej situ\u00e1cie.<\/strong><\/p>\n V\u0161etky n\u00e1lezy poch\u00e1dzaj\u00fa zo \u0160k\u00f3tskeho mora, severne od Antarkt\u00eddy. V\u00fdskum viedol Medzin\u00e1rodn\u00fd program objavovania oce\u00e1nov a\u00a0u\u017e v\u00a0roku 2019 spod morsk\u00e9ho dna zozbierali sediment\u00e1rne vzorky. T\u00e1to starovek\u00e1 DNA, skr\u00e1tene sedaDNA vznik\u00e1 premiestnen\u00edm \u010di vyzr\u00e1\u017ean\u00edm zvetran\u00fdch \u00falomkov horn\u00edn.<\/strong> Zemsk\u00fd povrch tvor\u00ed pribli\u017ene 75% sedaDNA, v\u00a0moriach a\u00a0oce\u00e1noch je jeho zast\u00fapenie takmer stopercentn\u00e9.<\/p>\n Vedci sa podrobne zaoberali modelmi po\u0161kodenia v obnoven\u00fdch fragmentoch DNA, aby presne ur\u010dili ich vek. Najstar\u0161ie vzorky mali okolo jedn\u00e9ho mili\u00f3na rokov. Doteraz najstar\u0161ia sedaDNA, ktor\u00e1 bola n\u00e1jden\u00e1 uzavret\u00e1 v arktickom permafroste, dosiahla vek 650 000 rokov.<\/p>\n \u013dadov\u00e9 vody Antarkt\u00eddy prekonali o\u010dak\u00e1vania v\u00fdskumn\u00edkov. zdroj: unsplash.com\n Vzorky boli v\u00fdnimo\u010dne dobre konzervovan\u00e9 v\u010faka n\u00edzkym teplot\u00e1m, zn\u00ed\u017een\u00fdm koncentr\u00e1ci\u00e1m kysl\u00edka a absencii UV \u017eiarenia.<\/strong> Vedci si nie s\u00fa ist\u00ed, ku ktor\u00e9mu druhu patr\u00ed najstar\u0161ia sedaDNA, hoci ur\u010dite poch\u00e1dza z eukaryota<\/strong> \u2013 \u010do znamen\u00e1, \u017ee patr\u00ed zviera\u0165u, rastline alebo hube a nie je z bakt\u00e9rie alebo v\u00edrusu.<\/p>\n T\u00edm okrem in\u00e9ho na\u0161iel aj jednobunkov\u00e9 organizmy \u2013 rozsievky \u2013 ktor\u00fdch vek sa odhaduje na 540 000 rokov.<\/strong> \u00a0V tomto \u010dase zv\u00fd\u0161en\u00e1 strata \u013eadu z \u013eadov\u00e9ho pr\u00edkrovu Antarkt\u00eddy a rast\u00face teploty oce\u00e1nov pravdepodobne podporili r\u00fdchly rast a rozmno\u017eovanie tohto typu fytoplankt\u00f3nu. Ten vo svetov\u00fdch oce\u00e1noch existuje dodnes a\u00a0tvor\u00ed z\u00e1klad v\u00e4\u010d\u0161iny morsk\u00fdch potravinov\u00fdch siet\u00ed.<\/p>\n \u201eIde o zauj\u00edmav\u00fa a d\u00f4le\u017eit\u00fa zmenu, ktor\u00e1 s\u00favis\u00ed s celosvetov\u00fdm a r\u00fdchlym n\u00e1rastom hladiny mor\u00ed a mas\u00edvnym \u00fabytkom \u013eadu v Antarkt\u00edde v d\u00f4sledku prirodzen\u00e9ho otep\u013eovania,\u201c<\/em><\/strong> hovor\u00ed geol\u00f3g Michael Weber z univerzity v nemeckom Bonne.<\/p>\n Najnov\u0161ia \u0161t\u00fadia dokazuje, \u017ee odbery sedaDNA pom\u00e1haj\u00fa pri rekon\u0161trukcii ekosyst\u00e9mov po\u010das stoviek tis\u00edc rokov, \u010do n\u00e1m d\u00e1va \u00faplne nov\u00fa \u00farove\u0148 poh\u013eadu na zmenu oce\u00e1nskeho \u017eivota.<\/p>\n V s\u00fa\u010dasnosti je na Antarkt\u00edde rozmiestnen\u00fdch 70 st\u00e1lych v\u00fdskumn\u00fdch stan\u00edc, ktor\u00e9 predstavuj\u00fa 29 kraj\u00edn zo v\u0161etk\u00fdch kontinentov na Zemi. zdroj: unsplash.com\n Vedci sa neust\u00e1le zdokona\u013euj\u00fa v odstra\u0148ovan\u00ed t\u00fdchto star\u00fdch fragmentov DNA zo zeme a minimalizuj\u00fa z\u00e1sah \u201emodernej\u201c DNA, aby z\u00edskali autentick\u00fd poh\u013ead na minulos\u0165.<\/strong><\/p>\n Pochopenie d\u00e1vnych klimatick\u00fdch zmien preto znamen\u00e1 presnej\u0161ie modely a predpovede toho, \u010do sa za\u010dne dia\u0165 v okol\u00ed okolo ju\u017en\u00e9ho p\u00f3lu po\u010das nasleduj\u00facich rokov.<\/strong><\/p>\n \u013dadov\u00fd kontinent postupne odkr\u00fdva \u010fal\u0161ie tajomstv\u00e1. Odborn\u00edci dlho predpokladali, \u017ee sa pod Antarkt\u00eddou nach\u00e1dza rozsiahla sie\u0165 jazier a \u00fast\u00ed riek.<\/strong> Doteraz neboli tieto prvky dostato\u010dne pre\u0161tudovan\u00e9, vedci takisto netu\u0161ili, \u010di sa v nich vyskytuj\u00fa \u017eiv\u00e9 organizmy.<\/p>\n V\u00fdskum spo\u010d\u00edval v spusten\u00ed kamery do jednej z riek. Prv\u00fdm prekvapen\u00edm sa stala \u0161trukt\u00fara pri\u013eahlej jaskyne. Vodn\u00fd st\u013apec v podzem\u00ed sa rozdelil na \u0161tyri alebo p\u00e4\u0165 odli\u0161n\u00fdch vrstiev vody te\u010d\u00facej v opa\u010dn\u00fdch smeroch. Druh\u00e9 prekvapenie nasledovalo, ke\u010f \u013eadov\u00fd tunel po chv\u00edli zakryli stovky mal\u00fdch, rozmazan\u00fdch \u0161kv\u0155n.<\/p>\n \u0160t\u00fadium minul\u00fdch a s\u00fa\u010dasn\u00fdch reakci\u00ed pol\u00e1rneho morsk\u00e9ho ekosyst\u00e9mu na zmenu \u017eivotn\u00e9ho prostredia je priam naliehavou z\u00e1le\u017eitos\u0165ou. zdroj: unsplash.com\n Spo\u010diatku si t\u00edm myslel, \u017ee ich vybavenie je chybn\u00e9. Po op\u00e4tovnom zaostren\u00ed fotoapar\u00e1tu si uvedomili, \u017ee objekt\u00edv sa hem\u017e\u00ed<\/strong> drobn\u00fdmi<\/strong> k\u00f4rovcami<\/strong> zn\u00e1mymi ako amfipody. Vedci bud\u00fa pokra\u010dova\u0165 v \u0161t\u00fadiu novoobjaven\u00e9ho podpovrchov\u00e9ho ekosyst\u00e9mu a d\u00fafaj\u00fa, \u017ee sa dozvedia viac o tom, ako sa \u017eiviny vo vode cirkuluj\u00fa cez podzemn\u00e9 vodn\u00e9 siete Antarkt\u00eddy.<\/p>\n Ani m\u00ednusov\u00e9 teploty v\u0161ak nie s\u00fa z\u00e1rukou toho, aby vz\u00e1cne ekosyst\u00e9my neohrozilo glob\u00e1lne otep\u013eovanie. \u201eKl\u00edma sa men\u00ed a veda e\u0161te mus\u00ed pochopi\u0165 niektor\u00e9 k\u013e\u00fa\u010dov\u00e9 body,“<\/strong> <\/em>vyjadril sa Craig Steven, oce\u00e1nograf z\u00a0N\u00e1rodn\u00e9ho in\u0161tit\u00fatu pre v\u00fdskum vody a\u00a0atmosf\u00e9ry. \u00daspe\u0161n\u00e9 objavy ale predstavuj\u00fa bl\u00ed\u017eiace sa zmeny v\u00a0procese spozn\u00e1vania antarktick\u00e9ho biotopu.<\/p>\n Zdroje: www.interestingengineering.com, www.livescience.com<\/strong><\/p>\n Zdroj titulnej fotografie: www.unsplash.com<\/strong><\/p>","protected":false},"excerpt":{"rendered":" Skryt\u00e9 ekosyst\u00e9my a\u00a0pravek\u00e9 DNA dokazuj\u00fa, \u017ee Antarkt\u00edda st\u00e1le patr\u00ed medzi najmenej presk\u00faman\u00e9 kontinenty. Medzin\u00e1rodn\u00e1 exped\u00edcia Ak sa niekedy pok\u00fa\u0161ame uchopi\u0165 koncept \u010dasu, netrv\u00e1 dlho, k\u00fdm<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[51],"tags":[],"class_list":["post-7951","post","type-post","status-publish","format-standard","hentry","category-archiv","two-columns"],"_links":{"self":[{"href":"https:\/\/instrid.sk\/en\/wp-json\/wp\/v2\/posts\/7951","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/instrid.sk\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/instrid.sk\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/instrid.sk\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/instrid.sk\/en\/wp-json\/wp\/v2\/comments?post=7951"}],"version-history":[{"count":0,"href":"https:\/\/instrid.sk\/en\/wp-json\/wp\/v2\/posts\/7951\/revisions"}],"wp:attachment":[{"href":"https:\/\/instrid.sk\/en\/wp-json\/wp\/v2\/media?parent=7951"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/instrid.sk\/en\/wp-json\/wp\/v2\/categories?post=7951"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/instrid.sk\/en\/wp-json\/wp\/v2\/tags?post=7951"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Vzorka prekonala doteraj\u0161\u00ed rekord<\/h3>\n
N\u00e1dej na kvalitnej\u0161\u00ed v\u00fdskum<\/h3>\n
Ohrozen\u00fd ekosyst\u00e9m<\/h3>\n