{"id":21048089,"date":"2019-10-15T08:51:22","date_gmt":"2019-10-15T06:51:22","guid":{"rendered":"https:\/\/geek.hr\/znanost\/?p=21048089"},"modified":"2020-09-26T03:18:01","modified_gmt":"2020-09-26T01:18:01","slug":"jaja","status":"publish","type":"post","link":"https:\/\/geek.hr\/znanost\/clanak\/jaja\/","title":{"rendered":"Za\u0161to ptice lije\u017eu jaja razli\u010ditih oblika?"},"content":{"rendered":"<p>Ona nisu samo sva\u010diji omiljeni doru\u010dak, nego i prava enigma. Znanstvenici ve\u0107 dugo poku\u0161avaju otkriti za\u0161to <a href=\"https:\/\/geek.hr\/znanost\/tag\/ptice\/\">ptice<\/a> lije\u017eu jaja razli\u010ditih oblika.<\/p>\n<p>Oblici su nevjerojatno razli\u010diti. Kolibri\u0107i pola\u017eu ona nalik na tic tac bombone, sove imaju jaja poput globusa, a \u0161ljuke lije\u017eu \u0161iljaste &#8220;ki\u0161ne kapi&#8221;.<\/p>\n<h4>Razne teorije<\/h4>\n<p>Tijekom godina je bilo razli\u010ditih obja\u0161njenja. Ptica koja se gnijezdi na liticama ima tendenciju polaganja \u0161iljastog jajeta jer ako se mora boriti, o\u0161tro jaje se vrti u krug &#8211; umjesto da se otkotrlja s ruba litice.<\/p>\n<p>Ptica s malom koli\u010dinom kalcija uvijek lije\u017ee okruglo jaje jer taj oblik zahtijeva najmanje ljuske. Jaje se tako\u0111er mora dobro uklopiti u gnijezdo, tako da se sva jaja mogu jednako inkubirati.<\/p>\n<p><a href=\"https:\/\/www.sciencemag.org\/news\/2017\/06\/surprisingly-simple-explanation-shape-bird-eggs\" target=\"_blank\" rel=\"noopener\">Znanstveni tim<\/a> s Princetona, Harvarda i drugih institucija je odlu\u010dio kona\u010dno razjasniti zagonetku. Analizirali su tako gotovo 50 tisu\u0107a primjeraka koja predstavljaju 1400 vrsta ptica.<\/p>\n<p>Uspore\u0111eni su oblici jaja razli\u010ditih ptica s obzirom na to \u0161to jedu, gdje se gnijezde, koliko su velike i koliko dobro lete.<\/p>\n<div id=\"attachment_21048091\" style=\"width: 310px\" class=\"wp-caption alignnone\"><img decoding=\"async\" aria-describedby=\"caption-attachment-21048091\" class=\"size-medium wp-image-21048091\" src=\"https:\/\/geek.hr\/znanost\/wp-content\/uploads\/sites\/14\/2019\/10\/F1.large_-300x181.jpg\" alt=\"\" width=\"300\" height=\"181\" srcset=\"https:\/\/geek.hr\/znanost\/wp-content\/uploads\/sites\/14\/2019\/10\/F1.large_-300x181.jpg 300w, https:\/\/geek.hr\/znanost\/wp-content\/uploads\/sites\/14\/2019\/10\/F1.large_-768x463.jpg 768w, https:\/\/geek.hr\/znanost\/wp-content\/uploads\/sites\/14\/2019\/10\/F1.large_-1200x724.jpg 1200w, https:\/\/geek.hr\/znanost\/wp-content\/uploads\/sites\/14\/2019\/10\/F1.large_-1000x600.jpg 1000w, https:\/\/geek.hr\/znanost\/wp-content\/uploads\/sites\/14\/2019\/10\/F1.large_-400x240.jpg 400w, https:\/\/geek.hr\/znanost\/wp-content\/uploads\/sites\/14\/2019\/10\/F1.large_.jpg 1280w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><p id=\"caption-attachment-21048091\" class=\"wp-caption-text\">Foto: Science<\/p><\/div>\n<h4>Leta\u010de sposobnosti<\/h4>\n<p>Rezultati pokazuju da na oblik jajeta ne utje\u010de ono \u0161to jedu ili koliko su velike. Analiza sugerira kako ptice koje su dobri leta\u010di pola\u017eu jaja koja su izdu\u017eena i \u0161iljatija. Tijela dobrih leta\u010da evoluirala su, u\u017ea su, a organi su im komprimiraniji kako bi im bilo lak\u0161e letjeti.<\/p>\n<p>Te promjene na tijelu utjecale su na formiranje svakog jajeta kod razli\u010ditih ptica. Oko bjelanjka i \u017eumanjka talo\u017ei se rastezljiva membrana koja daje jaju oblik, ka\u017ee studija. Ptice koje bolje lete imaju u\u017ee jajovode pa membrana ne mo\u017ee stvoriti \u0161iroko jaje. Ono tada mora biti ja\u010de i izdu\u017eenije, da pti\u0107 mo\u017ee stati i biti zdrav. Biolozi ka\u017eu da su sva ta otkri\u0107a intrigantna, ali daleko od posljednje rije\u010di.<\/p>\n<p>Postavljaju se sad i nova pitanja u vezi tih saznanja. Znanstvenici priznaju kako ima i vi\u0161e zagonetki nego na po\u010detku i nadaju se da \u0107e budu\u0107im analizama na njih i odgovoriti.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Enigme od kalcijevog karbonata<\/p>\n","protected":false},"author":10022,"featured_media":21048088,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"categories":[1,16345],"tags":[19384,19038,16625],"class_list":["post-21048089","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-znanost","category-evolucija","tag-jaja","tag-jaje","tag-ptice"],"modified_by":null,"_links":{"self":[{"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/posts\/21048089","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/users\/10022"}],"replies":[{"embeddable":true,"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/comments?post=21048089"}],"version-history":[{"count":0,"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/posts\/21048089\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/media\/21048088"}],"wp:attachment":[{"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/media?parent=21048089"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/categories?post=21048089"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/geek.hr\/znanost\/wp-json\/wp\/v2\/tags?post=21048089"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}