V pr\u016flomov\u00e9m objevu odhalili v\u011bdci mo\u017en\u00fd d\u016fkaz zat\u00edm nejstar\u0161\u00edch forem \u017eivota na Zemi. Kousky grafitu star\u00e9 ohromuj\u00edc\u00edch 3,95 miliardy let nazna\u010duj\u00ed, \u017ee \u017eivot mohl vzniknout brzy po vzniku na\u0161\u00ed planety.<\/p>\n\n
Objev byl u\u010din\u011bn ve 3,95 miliardy let star\u00fdch hornin\u00e1ch z Torngatsk\u00fdch hor v severn\u00edm Labradoru v Kanad\u011b. Krystaly grafitu vykazuj\u00ed specifick\u00fd izotopick\u00fd podpis, kter\u00fd nazna\u010duje jejich p\u016fvod z mikrobi\u00e1ln\u00ed aktivity.<\/p>\n\n
V p\u0159\u00edrod\u011b existuj\u00ed atomy uhl\u00edku ve dvou stabiln\u00edch izotopech: uhl\u00edk-12 a uhl\u00edk-13. \u017div\u00e9 organismy maj\u00ed tendenci up\u0159ednost\u0148ovat uhl\u00edk-12, proto\u017ee se snadn\u011bji zabudov\u00e1v\u00e1 do \u017eiv\u00e9 tk\u00e1n\u011b. Kdy\u017e tyto organismy zem\u0159ou a rozlo\u017e\u00ed se, zanech\u00e1vaj\u00ed po sob\u011b zbytky uhl\u00edku obohacen\u00e9 o uhl\u00edk-12.<\/p>\n\n
Krystaly grafitu nalezen\u00e9 v Torngatsk\u00fdch hor\u00e1ch vykazuj\u00ed toto vypov\u00eddaj\u00edc\u00ed obohacen\u00ed uhl\u00edkem-12, co\u017e nazna\u010duje, \u017ee byly pravd\u011bpodobn\u011b vytvo\u0159eny starov\u011bk\u00fdm mikrobi\u00e1ln\u00edm \u017eivotem.<\/p>\n\n
Krom\u011b izotopick\u00e9ho slo\u017een\u00ed podporuje teorii biogenn\u00edho p\u016fvodu tak\u00e9 uspo\u0159\u00e1dan\u00e1 struktura zrn grafitu. Zd\u00e1 se, \u017ee atomy uhl\u00edku pro\u0161ly stejn\u00fdm procesem zah\u0159\u00edv\u00e1n\u00ed, kter\u00fd vytvo\u0159il okoln\u00ed horniny, co\u017e nazna\u010duje, \u017ee nebyly zavedeny pozd\u011bji.<\/p>\n\n
V\u011bdci nav\u00edc pozorovali dal\u0161\u00ed geologick\u00e9 rysy, kter\u00e9 jsou v souladu s p\u0159\u00edtomnost\u00ed ran\u00e9ho \u017eivota, jako je p\u0159\u00edtomnost organick\u00e9 hmoty a miner\u00e1l\u016f, kter\u00e9 jsou \u010dasto spojov\u00e1ny s mikrobi\u00e1ln\u00ed aktivitou.<\/p>\n\n
Tento objev m\u00e1 v\u00fdznamn\u00e9 d\u016fsledky pro na\u0161e pochopen\u00ed p\u016fvodu \u017eivota na Zemi. Posouv\u00e1 \u010dasovou osu vzniku \u017eivota o 150 milion\u016f let zp\u011bt, co\u017e nazna\u010duje, \u017ee \u017eivot mohl za\u010d\u00edt je\u0161t\u011b d\u0159\u00edve, ne\u017e se d\u0159\u00edve myslelo.<\/p>\n\n
Zji\u0161t\u011bn\u00ed zpochyb\u0148uj\u00ed dlouho tradovanou v\u00edru, \u017ee povrch Zem\u011b byl b\u011bhem sv\u00e9 ran\u00e9 historie p\u0159\u00edli\u0161 hork\u00fd a nehostinn\u00fd pro \u017eivot. M\u00edsto toho nazna\u010duj\u00ed, \u017ee \u017eivot mohl naj\u00edt \u00fato\u010di\u0161t\u011b v hydroterm\u00e1ln\u00edch pr\u016fduchech nebo jin\u00fdch prost\u0159ed\u00edch, kter\u00e1 poskytovala ochranu p\u0159ed drsn\u00fdmi podm\u00ednkami.<\/p>\n\n
Stejn\u011b jako ka\u017ed\u00fd v\u00fdznamn\u00fd v\u011bdeck\u00fd objev, i tento vyvolal kontroverze. N\u011bkte\u0159\u00ed v\u011bdci tvrd\u00ed, \u017ee grafit bohat\u00fd na uhl\u00edk-12 mohly vytvo\u0159it anorganick\u00e9 procesy a \u017ee je pot\u0159eba v\u00edce d\u016fkaz\u016f k potvrzen\u00ed jeho biogenn\u00edho p\u016fvodu.<\/p>\n\n
V\u00fdzkumn\u00edci tyto obavy uzn\u00e1vaj\u00ed a pl\u00e1nuj\u00ed prov\u00e9st dal\u0161\u00ed anal\u00fdzy, aby sv\u016fj p\u0159\u00edpad pos\u00edlili. Zam\u00fd\u0161lej\u00ed zkoumat element\u00e1rn\u00ed a molekul\u00e1rn\u00ed slo\u017een\u00ed grafitu a miner\u00e1l\u016f s n\u00edm spojen\u00fdch, v nad\u011bji, \u017ee odhal\u00ed dal\u0161\u00ed stopy o povaze starov\u011bk\u00fdch forem \u017eivota, kter\u00e9 ho vytvo\u0159ily.<\/p>\n\n
Budouc\u00ed v\u00fdzkum se zam\u011b\u0159\u00ed na stanoven\u00ed element\u00e1rn\u00edho slo\u017een\u00ed grafitu a p\u0159idru\u017een\u00fdch miner\u00e1l\u016f. Anal\u00fdzou p\u0159\u00edtomnosti prvk\u016f, jako je dus\u00edk, s\u00edra a \u017eelezo, doufaj\u00ed v\u011bdci, \u017ee z\u00edskaj\u00ed lep\u0161\u00ed pochopen\u00ed metabolick\u00fdch proces\u016f starov\u011bk\u00fdch organism\u016f, kter\u00e9 po sob\u011b tyto stopy zanechaly.<\/p>\n\n
Toto prob\u00edhaj\u00edc\u00ed zkoum\u00e1n\u00ed slibuje, \u017ee prolije dal\u0161\u00ed sv\u011btlo na p\u016fvod \u017eivota na Zemi a na podm\u00ednky, kter\u00e9 podporovaly jeho ran\u00fd v\u00fdvoj.<\/p>","protected":false},"excerpt":{"rendered":"
Nejstar\u0161\u00ed stopy \u017eivota na Zemi 3,95 miliardy let star\u00fd grafit nazna\u010duje ranou mikrobi\u00e1ln\u00ed aktivitu V pr\u016flomov\u00e9m objevu odhalili v\u011bdci mo\u017en\u00fd d\u016fkaz zat\u00edm nejstar\u0161\u00edch forem \u017eivota na Zemi. Kousky grafitu star\u00e9…<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[212],"tags":[1216,207,137,6510,5722,4482,1865],"class_list":["post-4722","post","type-post","status-publish","format-standard","hentry","category-earth-science","tag-astrobiology","tag-geology","tag-paleontology","tag-origin-of-life","tag-ancient-life","tag-science-discovery","tag-scientific-breakthrough"],"_links":{"self":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/4722","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=4722"}],"version-history":[{"count":1,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/4722\/revisions"}],"predecessor-version":[{"id":4723,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/4722\/revisions\/4723"}],"wp:attachment":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media?parent=4722"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/categories?post=4722"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/tags?post=4722"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}