{"id":31932,"date":"2019-01-23T01:07:35","date_gmt":"2019-01-22T22:07:35","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=31932"},"modified":"2019-01-22T23:28:17","modified_gmt":"2019-01-22T20:28:17","slug":"modern-insan-yavrusuna-cinden-yeni-kardes-xujiayao-1","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2019\/01\/23\/modern-insan-yavrusuna-cinden-yeni-kardes-xujiayao-1","title":{"rendered":"Modern insan yavrusuna \u00c7in\u2019den yeni karde\u015f: Xujiayao 1"},"content":{"rendered":"

G\u00fcn\u00fcm\u00fczden 100.000 ila 224.000 y\u0131l \u00f6nce Do\u011fu Asya\u2019n\u0131n kimi b\u00f6lgelerinde Homo erectus<\/em>\u2019lar, Homo antecessor<\/em>\u2019lar, Homo heidelbergensis<\/em>\u2019ler, Denisovalar, Neandertallar, arkaik Homo<\/em>\u2019lar ve olmazsa olmaz, modern Homo sapiens<\/em>\u2019ler, yani bizler, ayn\u0131 co\u011frafyay\u0131 ve ayn\u0131 zaman\u0131 payla\u015fm\u0131\u015f\u0131z. Bunun en g\u00fc\u00e7l\u00fc kan\u0131tlar\u0131ndan birini Kuzey \u00c7in\u2019deki Nihewan Havzas\u0131\u2019ndan \u00e7\u0131kan \u00e7e\u015fit t\u00fcrl\u00fc insans\u0131ya ait fosiller olu\u015fturuyor. 1970\u2019lerde ger\u00e7ekle\u015ftirilen \u00fc\u00e7 b\u00fcy\u00fck kaz\u0131dan \u00e7\u0131kan 20 insans\u0131 fosili odur budur ara\u015ft\u0131rmalar\u0131n, giderek geli\u015fen g\u00f6r\u00fcnt\u00fcleme teknikleriyle tekrarlanan analizlerin konusu olmaya devam ediyor. Bu fosillerden biri, ad\u0131n\u0131 havzan\u0131n \u00f6zel bir noktas\u0131ndan alan Xujiayao 1, ke\u015ffedildikten 43 y\u0131l sonra, 16 Ocak 2019\u2019da Science Advances <\/em>dergisinde yay\u0131mlanan bir \u00e7al\u0131\u015fmaya konu oldu.<\/p>\n

Asl\u0131nda biz Xujiayao ismini, ayn\u0131 ad\u0131 ta\u015f\u0131yan fakat farkl\u0131 numaral\u0131 bir fosilden, Xujiayao 11\u2019den biliyoruz. Kendisi de, t\u0131pk\u0131 Xujiayao 1 gibi bir arkaik Homo<\/em>\u2019dur; yani Homo erectus<\/em> ile modern Homo sapiens<\/em> aras\u0131ndaki ge\u00e7i\u015fi temsil eden, hem arkaik hem modern insana ait \u00f6zellikler ta\u015f\u0131yan bir grubun mensubudur. 11 numaray\u0131 \u00f6zel yapan, modern insanlarda \u00e7ok nadir g\u00f6r\u00fclen bir do\u011fumsal anomaliyi sergiliyor olu\u015fuydu: parietal foramen a\u00e7\u0131kl\u0131\u011f\u0131. Kafatas\u0131n\u0131n tepe noktas\u0131nda kemiklerin tam birle\u015fmemesinden kaynaklanan bir delikle kendini g\u00f6steren bu genetik hastal\u0131k 5. ve 11. kromozomlarda bulunan ve kemik geli\u015fiminden sorumlu bir gendeki bozuklukla ili\u015fkili olarak ortaya \u00e7\u0131kar. Paleontologlar, 2013\u2019te bizlere tan\u0131tt\u0131klar\u0131 Xujiayao 11 i\u00e7in, modern insan ile arkaik Homo<\/em> aras\u0131ndaki muhtemel bir \u00e7iftle\u015fmenin \u00fcr\u00fcn\u00fc oldu\u011fu ve anomalinin de genetik yap\u0131s\u0131 tam \u00f6rt\u00fc\u015fmeyen bu iki grup aras\u0131ndaki \u00e7iftle\u015fmeye ba\u011fl\u0131 olarak ortaya \u00e7\u0131kt\u0131\u011f\u0131 h\u00fckm\u00fcnde bulunmu\u015flard\u0131. Hatta ayn\u0131 anomaliye ba\u015fka baz\u0131 insans\u0131larda rastlanm\u0131\u015f olmas\u0131, farkl\u0131 gruplar aras\u0131ndaki \u00e7iftle\u015fme ihtimalini g\u00fc\u00e7lendirmi\u015fti. Peki Xujiayao 1\u2019i ilgin\u00e7 k\u0131lan ve Science<\/em>\u2019taki makalenin konusu yapan ne oldu? Cevab\u0131 tek s\u00f6zc\u00fckle verelim: Di\u015fleri.
\nDi\u015fler fosil ara\u015ft\u0131rmalar\u0131 bak\u0131m\u0131ndan boyu k\u00fc\u00e7\u00fck etkisi b\u00fcy\u00fck bir malzemedir. Hem en s\u0131k rastlanan v\u00fccut par\u00e7alar\u0131ndan biridir hem de sergiledi\u011fi ritmik b\u00fcy\u00fcme \u015fablonu ara\u015ft\u0131rmac\u0131lara o t\u00fcr hakk\u0131nda pek \u00e7ok \u015fey s\u00f6yler. D\u0131\u015f tabaka y\u00fczeyindeki b\u00fcy\u00fcme \u00e7izgileri sayesinde bir yandan organizman\u0131n g\u00fcnl\u00fck rutini hakk\u0131nda fikir verir, di\u011fer yandan uzun vadedeki gidi\u015fat\u0131na, ya\u015fam tarz\u0131na dair bir kay\u0131t sunar. En az 104.000 y\u0131l \u00f6nce ya\u015fam\u0131\u015f ve 6,5 ya\u015f civar\u0131nda hayat\u0131 son bulmu\u015f bir \u00e7ocu\u011fun \u00fcst \u00e7enesindeki bu yedi di\u015f de ayn\u0131 \u015fekilde bizlere kendi t\u00fcr\u00fc, yani modern insan\u0131n birka\u00e7 ad\u0131m uza\u011f\u0131ndaki bu arkaik sapiens hakk\u0131nda bir\u00e7ok \u015fey anlatt\u0131.<\/p>\n

\"\"
Solda Xujiayao\u2019nun \u00fcst \u00e7ene kemi\u011fi; kesici di\u015fler, k\u00f6pek di\u015fleri, ikinci az\u0131di\u015fleri ve k\u00fc\u00e7\u00fck az\u0131di\u015fleri h\u00e2l\u00e2 dama\u011fa g\u00f6m\u00fcl\u00fc. Sa\u011fda di\u015flerin 3 boyutlu rekonstr\u00fcksiyonu. Kaynak: Song Xing.<\/figcaption><\/figure>\n

Xujiayao 1 fiziksel \u00f6zellikleri bak\u0131m\u0131ndan H. erectus<\/em>, Neandertal ve modern insan\u0131n bir mozai\u011fi gibi. Kafatas\u0131n\u0131n kal\u0131nl\u0131\u011f\u0131 ile di\u015flerin boyutu en bariz arkaik \u00f6zellikleri; fakat o b\u00fcy\u00fck di\u015flerinin anatomik ve geli\u015fimsel \u00f6zellikleri modern insan\u0131nkiyle daha \u00f6nce hi\u00e7 rastlanmad\u0131\u011f\u0131 kadar \u00f6rt\u00fc\u015f\u00fcyor. \u00c7in Bilimler Akademisi\u2019ne ba\u011fl\u0131 Omurgal\u0131 Paleontolojisi ve Paleoantropolojisi Enstit\u00fcs\u00fc\u2019nden Song Xing\u2019in ba\u015f\u0131n\u0131 \u00e7ekti\u011fi uluslararas\u0131 bir ekip, faz-kontrast x \u0131\u015f\u0131n\u0131 sinkrotron mikrotomografisi denen ileri d\u00fczey bir g\u00f6r\u00fcnt\u00fcleme tekni\u011finden yararlanarak minik Xujiayao 1\u2019in di\u015flerini \u00e7e\u015fitli a\u00e7\u0131lardan incelemi\u015fler: Ortalama k\u00f6k uzama h\u0131z\u0131, di\u015ftac\u0131n\u0131n olu\u015fum zaman\u0131, perikimata da\u011f\u0131l\u0131m\u0131 (di\u015f \u00fczerinde kademeli olarak artan yatay geli\u015fim \u00e7izgileri) ve ilk az\u0131di\u015finin di\u015feti \u00fczerinde belirme zaman\u0131 bunlardan belli ba\u015fl\u0131lar\u0131. Bu \u00f6zelliklerin as\u0131l \u00f6nemi ait oldu\u011fu organizman\u0131n ya\u015fam evreleri, di\u011fer bir deyi\u015fle s\u00fctten kesilme zaman\u0131, ebeveyne ba\u011f\u0131ml\u0131 \u00e7ocukluk d\u00f6neminin uzunlu\u011fu, ergenlik ve ilk \u00fcreme ya\u015f\u0131na ge\u00e7i\u015f zaman\u0131 gibi \u00e7ok kritik konular hakk\u0131nda verdi\u011fi ipu\u00e7lar\u0131. \u00d6rne\u011fin az\u0131 di\u015finin belirme ya\u015f\u0131 t\u00fcm b\u00fcy\u00fck maymunlarda s\u00f6z konusu ya\u015fam evreleriyle yak\u0131ndan ili\u015fkili. \u0130nsanlarda 5-7 ya\u015f aras\u0131 olan az\u0131di\u015fi \u00e7\u0131karma zaman\u0131 Pleistosen insans\u0131lar\u0131nda geriye gidildik\u00e7e erkene \u00e7ekiliyor. Di\u011fer bir deyi\u015fle az\u0131di\u015fi ne kadar erken \u00e7\u0131karsa ilgili insans\u0131, modern insan skalas\u0131ndan o kadar uzakla\u015f\u0131p maymun skalas\u0131na yakla\u015fm\u0131\u015f oluyor. Bu da modern insana yakla\u015ft\u0131k\u00e7a di\u015flerin olgunla\u015fmas\u0131n\u0131n yava\u015flad\u0131\u011f\u0131 anlam\u0131na geliyor. Bu anlamda Homo erectus<\/em> ilk insans\u0131larla modern insan aras\u0131nda bir yerlerde. Az\u0131di\u015fini \u00f6lmeden k\u0131sa bir s\u00fcre \u00f6nce, 6 ya\u015f civar\u0131nda \u00e7\u0131karm\u0131\u015f olan Xujiayao 1 ise modern insanla \u00f6rt\u00fc\u015f\u00fcyor; 3,5 ya\u015f civar\u0131nda ba\u015flayan kal\u0131n mine tabakas\u0131 olu\u015fumu ve perikimata da\u011f\u0131l\u0131m\u0131 da ayn\u0131 \u015fekilde modern insan \u015fablonunu izliyor. Xujiayao\u2019yu modern insandan ay\u0131ran tek \u00f6zellik k\u00f6k uzamas\u0131n\u0131n bu fosil \u00e7ocukta daha h\u0131zl\u0131 ger\u00e7ekle\u015fiyor olmas\u0131. Di\u015f geli\u015fim evrelerindeki bu e\u015fg\u00fcd\u00fcm modern insan\u0131n ya\u015fam \u00f6yk\u00fcs\u00fc i\u00e7in ge\u00e7erli a\u015f\u0131r\u0131 uzun ba\u011f\u0131ml\u0131 \u00e7ocukluk evresi, nispeten ge\u00e7 ba\u015flayan \u00fcreme zaman\u0131 ve uzun ya\u015fam s\u00fcresi gibi \u00f6zelliklerin Xujiayao 1 i\u00e7in de ge\u00e7erli oldu\u011funu g\u00f6steriyor. Demek oluyor ki modern insana atfedilen bu \u00f6zellikler modern insan morfolojisinin ortaya \u00e7\u0131kmas\u0131ndan \u00f6nce kendini g\u00f6stermi\u015f. Yani Xujiayao 1, 7. ya\u015f\u0131n\u0131 g\u00f6rememi\u015f de olsa mensubu oldu\u011fu grup t\u0131pk\u0131 modern insan gibi \u201cyava\u015f ya\u015fay\u0131p ge\u00e7 \u00f6lm\u00fc\u015f.\u201d<\/p>\n

Kaynaklar:<\/strong><\/p>\n

1) S. Xing ve ark., \u201cFirst systematic assessment of dental growth and development in an archaic hominin (genus, Homo<\/em>) from East Asia,\u201d Science Advances<\/em>, 16 Ocak 2019: Cilt 5, no. 1.<\/p>\n

2) Chinese Academy Of Sciences Headquarters, \u201cDental study of juvenile archaic Homo fossil gives clues about human development,\u201d 16 Ocak 2019; https:\/\/www.eurekalert.org\/pub_releases\/2019-01\/caos-dso011619.php.<\/p>\n","protected":false},"excerpt":{"rendered":"

G\u00fcn\u00fcm\u00fczden 100.000 ila 224.000 y\u0131l \u00f6nce Do\u011fu Asya\u2019n\u0131n kimi b\u00f6lgelerinde Homo erectus\u2019lar, Homo antecessor\u2019lar, Homo heidelbergensis\u2019ler, Denisovalar, Neandertallar, arkaik Homo\u2019lar ve olmazsa olmaz, modern Homo sapiens\u2019ler, yani bizler, ayn\u0131 co\u011frafyay\u0131 ve ayn\u0131 zaman\u0131 payla\u015fm\u0131\u015f\u0131z. Bunun en g\u00fc\u00e7l\u00fc kan\u0131tlar\u0131ndan birini Kuzey \u00c7in\u2019deki Nihewan Havzas\u0131\u2019ndan \u00e7\u0131kan \u00e7e\u015fit t\u00fcrl\u00fc insans\u0131ya ait fosiller olu\u015fturuyor. 1970\u2019lerde ger\u00e7ekle\u015ftirilen \u00fc\u00e7 b\u00fcy\u00fck kaz\u0131dan […]<\/p>\n","protected":false},"author":184,"featured_media":31933,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19,4419],"tags":[4457,4458,4459,4456],"class_list":["post-31932","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","category-paleontoloji","tag-arkaik-homo","tag-insansilarda-dis-gelisimi","tag-kuzey-cin","tag-xujiayao-1"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/31932","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/users\/184"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=31932"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/31932\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media\/31933"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=31932"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=31932"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=31932"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}