{"id":91468,"date":"2026-01-23T07:07:12","date_gmt":"2026-01-23T07:07:12","guid":{"rendered":"https:\/\/www.europesays.com\/ee\/91468\/"},"modified":"2026-01-23T07:07:12","modified_gmt":"2026-01-23T07:07:12","slug":"urgsetel-kaladel-oli-neli-silma-loodus","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ee\/91468\/","title":{"rendered":"\u00dcrgsetel kaladel oli neli silma | Loodus"},"content":{"rendered":"

Kui iidsetesse meredesse ilmusid \u00fcle poole miljardi aasta tagasi esimesed kalad, siis alguses oli v\u00e4hemalt m\u00f5nel neist neli silma.<\/p>\n

Nii v\u00e4idavad Hiina ja Briti teadlased, kes on uurinud ja t\u00f5lgendanud Hiinast leitud 518 miljoni aasta vanuseid fossiile.<\/p>\n

Fossiile oli k\u00fcmme, neid oli kahte liiki, mis m\u00f5lemad kuulusid l\u00f5uatute kalade m\u00fcllokunmingiidide sekka.<\/p>\n

M\u00fcllokunmingiidid on teadusele tuntud umbes sajandivahetusest alates, mil nende fossiile esimest korda sealtsamast Hiinast leiti ja tuvastati. Neid peetakse n\u00fc\u00fcd \u00fchtedeks varajasemateks selgroogseteks loomadeks maakera ajaloos \u00fcle\u00fcldse.<\/p>\n

Xiangtong Lei ja Sihang Zhang Yunnani \u00dclikoolist Kunmingis kirjutavad ajakirjas Nature<\/a>, et k\u00f5igil neil fossiilidel oli lisaks pea k\u00fclgedel asetsenud kahele silmale n\u00e4ha \u00fcsna samasuguseid moodustisi ka keset n\u00e4gu.<\/p>\n

Neid moodustisi on paleontoloogid k\u00fcll ka varem n\u00e4inud, kuid mitte lisasilmadena t\u00f5lgendanud.<\/p>\n

<\/p>\n

Lei, Zhang ja kaaslased uurisid neid struktuure n\u00fc\u00fcd varasemast p\u00f5hjalikumalt, muu hulgas mitut t\u00fc\u00fcpi elektronmikroskoopide abiga, ja leidid neis mitmeid sarnasusi samade fossiilide k\u00fclgsete silmadega.<\/p>\n

N\u00e4iteks leidus kesksemates organites valgustundliku pigmentaine melaniiniga tegelevaid melanosoome, rakuorganelle, mida leidub ka selgroogsete loomade silmades.<\/p>\n

Neis kesksemates organites v\u00f5is t\u00e4heldada ka l\u00e4\u00e4tselaadseid struktuure, mis viitavad, et tegu ei olnud lihtsalt valgustundlike t\u00e4pikestega, vaid nad suutsid t\u00f5en\u00e4oliselt luua ka \u00fcmbruskonnast kujutise. Samasugused l\u00e4\u00e4tsed olid olemas ka kalade k\u00fclgsilmades.<\/p>\n

Autorid seostavad m\u00fcllokunmingiidide keskmised silmad niinimetatud pineaalkompleksiga, kaladel, kahepaiksetel ja roomajatel esineva ajustruktuuristuga, mis on valgustundlik ja n\u00f5ristab unehormooni melatoniini.<\/p>\n

Imetajatel on pineaalkompleksist alles vaid selle \u00fchest osast arenenud k\u00e4bin\u00e4\u00e4re.<\/p>\n

Autorid m\u00e4rgivad, et m\u00fcllokunmingiididele v\u00f5is nelja silmaga n\u00e4gemine h\u00e4sti \u00e4ra kuluda, sest nad olid saakloomad paljudele kambriumi ajastu kiskjatele, keda neil tasus siis aegsasti ja selgesti m\u00e4rgata.<\/p>\n

Pildil on \u00fcks uuritud kalaliikidest Haikouichthys ercaicunensis kunstniku kujutuses.<\/p>\n

Teadusuudised on Vikerraadios eetris esmasp\u00e4evast reedeni ca kell 8.35 ja laup\u00e4eval ca kell 8.25.<\/p>\n","protected":false},"excerpt":{"rendered":"Kui iidsetesse meredesse ilmusid \u00fcle poole miljardi aasta tagasi esimesed kalad, siis alguses oli v\u00e4hemalt m\u00f5nel neist neli…\n","protected":false},"author":2,"featured_media":91469,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[80],"tags":[26,27,37,33,35,34,36,31,32,21097,21,44664,1688,44663,28,29,95,44662,44076,19,25,13296,23,24,22,20,30,92,93,94],"class_list":{"0":"post-91468","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-maailm","8":"tag-breaking-news","9":"tag-breakingnews","10":"tag-ee","11":"tag-eesti","12":"tag-eesti-keel","13":"tag-estonia","14":"tag-estonian","15":"tag-featured-news","16":"tag-featurednews","17":"tag-fossiil","18":"tag-headlines","19":"tag-kabinaare","20":"tag-kala","21":"tag-kambrium","22":"tag-latest-news","23":"tag-latestnews","24":"tag-maailm","25":"tag-melaniin","26":"tag-melatoniin","27":"tag-news","28":"tag-populaarseimad-lood","29":"tag-silm","30":"tag-top-stories","31":"tag-topstories","32":"tag-uldised-uudised","33":"tag-uudised","34":"tag-viimased-uudised","35":"tag-world","36":"tag-world-news","37":"tag-worldnews"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ee\/115943154846911231","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/posts\/91468","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/comments?post=91468"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/posts\/91468\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/media\/91469"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/media?parent=91468"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/categories?post=91468"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ee\/wp-json\/wp\/v2\/tags?post=91468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}