V rozlehl\u00e9 krajin\u011b Grand Teton National Park ve Wyomingu se odehr\u00e1v\u00e1 fascinuj\u00edc\u00ed vztah mezi antilopami vidloroh\u00fdmi a vlky. Studie proveden\u00e1 Wildlife Conservation Society odhalila, \u017ee ml\u00e1\u010fata vyr\u016fstaj\u00edc\u00ed pobl\u00ed\u017e vlk\u016f m\u011bla \u010dty\u0159ikr\u00e1t vy\u0161\u0161\u00ed m\u00edru p\u0159e\u017eit\u00ed ne\u017e ta v oblastech bez vlk\u016f. Tento p\u0159ekvapiv\u00fd n\u00e1lez nazna\u010duje, \u017ee vlci hraj\u00ed z\u00e1sadn\u00ed roli v udr\u017eov\u00e1n\u00ed populac\u00ed antilop vidloroh\u00fdch t\u00edm, \u017ee kontroluj\u00ed predaci kojot\u016f.<\/p>\n\n
Hluboko v zemi Mississippi objevili v\u011bdci pozoruhodn\u00e9 fos\u00edlie, kter\u00e9 vrhaj\u00ed sv\u011btlo na p\u016fvod prim\u00e1t\u016f v Severn\u00ed Americe. Teilhardina magnoliana, stromov\u00fd prim\u00e1t v\u00e1\u017e\u00edc\u00ed pouh\u00fdch 30 gram\u016f, se potuloval po kontinentu p\u0159ed p\u0159ibli\u017en\u011b 55,8 miliony let. Tento objev, veden\u00fd K. Christopherem Beardem z Carnegie Museum of Natural History, podporuje teorii, \u017ee prim\u00e1ti p\u0159ekro\u010dili Beringovu \u00fa\u017einu z Asie a otev\u0159eli cestu pro p\u0159\u00edpadn\u00fd vznik \u010dlov\u011bka.<\/p>\n\n
U pob\u0159e\u017e\u00ed severoz\u00e1padn\u00edho Tich\u00e9ho oce\u00e1nu se objevil ponur\u00fd jev zn\u00e1m\u00fd jako \u201emrtv\u00e1 z\u00f3na\u201c v oce\u00e1nu. Tato oblast vody m\u00e1 nebezpe\u010dn\u011b n\u00edzkou hladinu kysl\u00edku, kter\u00e1 dus\u00ed mo\u0159sk\u00e9 \u017eivo\u010dichy, kte\u0159\u00ed nemohou uniknout. V\u00fdzkumn\u00edci z Oregon State University analyzovali desetilet\u00ed dat a dosp\u011bli k z\u00e1v\u011bru, \u017ee tuto ned\u00e1vno vzniklou mrtvou z\u00f3nu zp\u016fsobuje kombinace v\u011btr\u016f a proud\u016f, kter\u00e9 naru\u0161uj\u00ed ekosyst\u00e9m a podporuj\u00ed r\u016fst bakteri\u00ed vy\u010derp\u00e1vaj\u00edc\u00edch kysl\u00edk.<\/p>\n\n
V ru\u0161n\u00e9m m\u011bst\u011b Montpellier ve Francii odhalila jedna studie pozoruhodnou p\u0159izp\u016fsobivost rostlin m\u011bstsk\u00e9mu prost\u0159ed\u00ed. Crepis sancta, plevel podobn\u00fd pampeli\u0161k\u00e1m, se vyvinul tak, aby produkoval r\u016fzn\u00e9 typy semen: n\u011bkter\u00e1 un\u00e1\u0161en\u00e1 v\u011btrem a jin\u00e1 z\u016fst\u00e1vaj\u00edc\u00ed bl\u00edzko mate\u0159sk\u00e9 rostliny. M\u011bstsk\u00e1 C. sancta se p\u0159izp\u016fsobila sv\u00e9mu okol\u00ed t\u00edm, \u017ee produkuje v\u00edce semen, kter\u00e1 padaj\u00ed na zem a vyu\u017e\u00edvaj\u00ed \u017eivinami bohatou p\u016fdu, kter\u00e1 podporuje jejich p\u0159e\u017eit\u00ed uprost\u0159ed betonu a asfaltu.<\/p>\n\n
Pod kaln\u00fdmi vodami ba\u017ein a \u0159ek m\u00e1 americk\u00fd alig\u00e1tor fascinuj\u00edc\u00ed d\u00fdchac\u00ed soustavu, kter\u00e1 mu umo\u017e\u0148uje snadno man\u00e9vrovat. Pr\u016fkopnick\u00e1 studie proveden\u00e1 v\u011bdci z University of Utah zdokumentovala dvoj\u00ed funkci sval\u016f, kter\u00e9 rozp\u00ednaj\u00ed a stahuj\u00ed alig\u00e1to\u0159\u00ed pl\u00edce. Tyto svaly nejen usnad\u0148uj\u00ed d\u00fdch\u00e1n\u00ed, ale tak\u00e9 p\u0159isp\u00edvaj\u00ed k alig\u00e1torov\u00fdm pohyb\u016fm pod vodou. Kdy\u017e se alig\u00e1tor pot\u00e1p\u00ed, svaly posunuj\u00ed jeho pl\u00edce sm\u011brem k ocasu; kdy\u017e stoup\u00e1 k hladin\u011b, posunuj\u00ed je sm\u011brem k hlav\u011b; a kdy\u017e se v\u00e1l\u00ed, posunuj\u00ed je na ob\u011b strany. Tento plicemi poh\u00e1n\u011bn\u00fd pohonn\u00fd syst\u00e9m umo\u017e\u0148uje alig\u00e1torovi efektivn\u011b plavat bez pot\u0159eby ploutv\u00ed nebo ploutvovit\u00fdch kon\u010detin.<\/p>\n\n
Schopnost americk\u00e9ho alig\u00e1tora vyu\u017e\u00edvat sv\u00e9 pl\u00edce jak k d\u00fdch\u00e1n\u00ed, tak k pohybu zd\u016fraz\u0148uje z\u00e1sadn\u00ed roli, kterou hraje plicn\u00ed funkce u vodn\u00edch \u017eivo\u010dich\u016f. Podobn\u00e9 plicemi poh\u00e1n\u011bn\u00e9 pohonn\u00e9 mechanismy byly pozorov\u00e1ny u jin\u00fdch vodn\u00edch druh\u016f, jako jsou \u017e\u00e1by, mloci a \u017eelvy. Pochopen\u00ed slo\u017eitosti plicn\u00ed funkce u t\u011bchto \u017eivo\u010dich\u016f poskytuje cenn\u00e9 poznatky o jejich evolu\u010dn\u00edch adaptac\u00edch a ekologick\u00fdch rol\u00edch.<\/p>","protected":false},"excerpt":{"rendered":"
P\u0159\u00edrodn\u00ed divy: Odhalen\u00ed tajemstv\u00ed p\u0159\u00edrody Antilopa vidloroha a role vlk\u016f V rozlehl\u00e9 krajin\u011b Grand Teton National Park ve Wyomingu se odehr\u00e1v\u00e1 fascinuj\u00edc\u00ed vztah mezi antilopami vidloroh\u00fdmi a vlky. Studie proveden\u00e1…<\/p>\n","protected":false},"author":6,"featured_media":24061,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[244],"tags":[1647,254,219,136,252,97],"class_list":["post-1522","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-natural-history","tag-adaptation","tag-wildlife","tag-ecology","tag-evolution","tag-nature","tag-science"],"_links":{"self":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/1522","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\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/comments?post=1522"}],"version-history":[{"count":1,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/1522\/revisions"}],"predecessor-version":[{"id":1523,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/1522\/revisions\/1523"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media\/24061"}],"wp:attachment":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media?parent=1522"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/categories?post=1522"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/tags?post=1522"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}