{"id":15431,"date":"2016-06-01T13:33:39","date_gmt":"2016-06-01T10:33:39","guid":{"rendered":"http:\/\/109.232.216.219\/~bilimvegelecek\/?p=15431"},"modified":"2017-12-29T13:56:37","modified_gmt":"2017-12-29T10:56:37","slug":"modern-insan-populasyonlarinda-arkaik-izler-diger-insan-turleriyle-ne-kadar-karistik","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2016\/06\/01\/modern-insan-populasyonlarinda-arkaik-izler-diger-insan-turleriyle-ne-kadar-karistik","title":{"rendered":"Modern insan pop\u00fclasyonlar\u0131nda arkaik izler:\u00a0Di\u011fer insan t\u00fcrleriyle ne kadar kar\u0131\u015ft\u0131k?"},"content":{"rendered":"

G\u00fcn\u00fcm\u00fcz verileriyle anatomik olarak modern insan\u0131n k\u00f6keni Afrika\u2019ya, 200 bin y\u0131l \u00f6ncesine dayan\u0131r. Homo sapiens\u2019in tarih sahnesine \u00e7\u0131kt\u0131\u011f\u0131nda, ya\u015fayan tek insan t\u00fcr\u00fc olmad\u0131\u011f\u0131 biliniyor. D\u00fcnya \u00fczerinde ge\u00e7irdi\u011fi 200 bin y\u0131l i\u00e7erisinde modern insan\u0131n, Homo neanderthalis ve Denisovan gibi arkaik homininler ile gen al\u0131\u015fveri\u015finde bulundu\u011fu ve kar\u0131\u015ft\u0131\u011f\u0131 tespit edildi. Bu gen ak\u0131\u015f\u0131, g\u00f6\u00e7 etti\u011fi b\u00f6lgelere uyum sa\u011flamas\u0131 a\u00e7\u0131s\u0131ndan \u00f6nemli katk\u0131lar sunmu\u015ftur. <\/em><\/p>\n

Evrimsel genomik, ya\u015fam\u0131n genetik kay\u0131tlar\u0131 \u00fczerine kurulmu\u015f, ya\u015fayan t\u00fcrlerden en son evrimsel ortak ataya (LUCA: Last Universal Common Ancestor) kadar olan t\u00fcm canl\u0131lar\u0131n birbirleriyle ili\u015fkilerini ve evrimsel s\u00fcre\u00e7lerini ortaya koyan1<\/sup> ve bir\u00e7ok bilimsel alandan beslenen bilim dal\u0131d\u0131r. 20. y\u00fczy\u0131ldan itibaren kal\u0131t\u0131m materyali DNA\u2019n\u0131n yap\u0131s\u0131n\u0131n ke\u015ffi ile ayn\u0131 y\u00fczy\u0131l\u0131n sonunda ya\u015fanan teknolojik ilerleme, b\u00fcy\u00fck genomik veriler \u00fczerinde \u00e7al\u0131\u015fmay\u0131 m\u00fcmk\u00fcn k\u0131lm\u0131\u015ft\u0131r. G\u00fcn\u00fcm\u00fczde t\u00fcrlerin aras\u0131nda ne kadar gen ak\u0131\u015f\u0131 oldu\u011fu ve bu gen ak\u0131\u015f\u0131n\u0131n ne zaman ger\u00e7ekle\u015fti\u011fi belirlenebilmektedir.<\/p>\n

Evrimsel genomi\u011fin ilgilendi\u011fi en temel kavramlardan biri biyo\u00e7e\u015fitliliktir. En genel tan\u0131m\u0131yla biyo\u00e7e\u015fitlilik, Yerk\u00fcre\u2019de ya\u015fayan t\u00fcm karasal ve denizel organizmalar\u0131n t\u00fcr i\u00e7i ve t\u00fcrler aras\u0131; ayr\u0131ca var olan ekosistemler aras\u0131ndaki biyolojik de\u011fi\u015fiklikleri kapsayan terimdir2<\/sup>. Bu tan\u0131mlama \u00e7er\u00e7evesinde, ilk hipotetik atasal formdan itibaren canl\u0131lar, genetik materyallerinde meydana gelen de\u011fi\u015fimlerle biyo\u00e7e\u015fitlili\u011fi \u00fcretmeye ba\u015flam\u0131\u015flard\u0131r. T\u00fcm bu de\u011fi\u015fimler, evrimsel s\u00fcre\u00e7leri besleyerek t\u00fcrle\u015fmeye yol a\u00e7ar.<\/p>\n

T\u00fcm organizmalar ya\u015fad\u0131klar\u0131 ekosistem ile ili\u015fki i\u00e7indedir. Ancak s\u00f6z konusu organizma insan oldu\u011funda, \u00e7al\u0131\u015fman\u0131n bir d\u00fczleminin de k\u00fclt\u00fcr olmas\u0131 ka\u00e7\u0131n\u0131lmaz hale gelir. Zira e\u015f se\u00e7iminden dilin kullan\u0131m\u0131na, toplumsal ili\u015fkilerden alet becerisine kadar bir\u00e7ok k\u00fclt\u00fcrel fakt\u00f6r insan\u0131n biyok\u00fclt\u00fcrel evriminde s\u00f6z sahibidir, bu da disiplinler aras\u0131 \u00e7al\u0131\u015fmalar\u0131 zorunlu k\u0131lar. \u0130nsan evrimsel genomi\u011fi, antropoloji, linguistik, paleoklimatoloji, tarih ve hatta y\u00f6ntemsel a\u00e7\u0131dan bilgisayar bilimleri ile i\u015fbirli\u011fi halinde \u00e7al\u0131\u015f\u0131r.<\/p>\n

Genetik \u00e7e\u015fitlili\u011fi etkileyen fakt\u00f6rler<\/strong><\/p>\n

Genetik \u00e7e\u015fitlilik, pop\u00fclasyon geneti\u011fi ara\u015ft\u0131rmalar\u0131n\u0131n temel konusudur. Genetik \u00e7e\u015fitli\u011fi \u00f6l\u00e7en en temel birim olan allel s\u0131kl\u0131\u011f\u0131n\u0131 etkileyen bir\u00e7ok fakt\u00f6r vard\u0131r. Bunlardan en \u00f6nemlileri mutasyon, rekombinasyon, do\u011fal se\u00e7ilim, genetik s\u00fcr\u00fcklenme ve g\u00f6\u00e7t\u00fcr. S\u00f6z konusu etkilerin bir k\u0131sm\u0131 genetik \u00e7e\u015fitlili\u011fin kayna\u011f\u0131, bir k\u0131sm\u0131 ise \u00e7e\u015fitlili\u011fi azaltan fakt\u00f6rler aras\u0131ndad\u0131r. Bu \u015fekilde canl\u0131l\u0131\u011f\u0131n devam\u0131 i\u00e7in gereken denge sa\u011flanm\u0131\u015f olur.<\/p>\n

Mutasyon<\/strong>, genetik materyalin diziliminde meydana gelen de\u011fi\u015fimlerdir ve \u00e7e\u015fitlili\u011fi ortaya \u00e7\u0131karan en \u00f6nemli fakt\u00f6r olarak bilinir. Her bir mutasyon, tek bir h\u00fccrede meydana gelir. E\u011fer mutasyon \u00fcreme h\u00fccrelerinde ger\u00e7ekle\u015firse yavrulara aktar\u0131labilir, dolay\u0131s\u0131yla soyolu\u015fu takip eden evrimsel \u00e7al\u0131\u015fmalarda kullan\u0131labilir. Di\u011fer t\u00fcm s\u00fcre\u00e7leri d\u0131\u015flay\u0131p, sadece mutasyon d\u00fc\u015f\u00fcn\u00fcld\u00fc\u011f\u00fcnde, mutasyonun meydana geldi\u011fi allelin s\u0131kl\u0131\u011f\u0131, yeni bir allelin olu\u015fmas\u0131 nedeniyle d\u00fc\u015fer, bu da genetik \u00e7e\u015fitlili\u011fin artmas\u0131na neden olur.<\/p>\n

Di\u011fer bir fakt\u00f6r olan rekombinasyon<\/strong>, mayoz b\u00f6l\u00fcnme s\u0131ras\u0131nda meydana gelen ve pop\u00fclasyonlar\u0131n \u00e7evreye adaptasyonunu sa\u011flayan, kromozomlardaki par\u00e7a de\u011fi\u015fimidir. S\u00f6z konusu par\u00e7a de\u011fi\u015fimi, farkl\u0131 ba\u011flant\u0131l\u0131 allellerden yeni bir allel kombinasyonu olu\u015fturarak genetik \u00e7e\u015fitlili\u011fin artmas\u0131nda rol oynar.3<\/sup><\/p>\n

Mutasyon ve rekombinasyon, genetik materyali fiziki olarak de\u011fi\u015ftirme yoluyla \u00e7e\u015fitlili\u011fi art\u0131r\u0131rken, genetik s\u00fcr\u00fcklenme<\/strong> allel s\u0131kl\u0131\u011f\u0131n\u0131 de\u011fi\u015ftirerek \u00e7e\u015fitlili\u011fi azalt\u0131r. Her yeni nesilde rasgele se\u00e7ilen bir grup allel bir sonraki nesle aktar\u0131l\u0131r. Dolay\u0131s\u0131yla, bir \u00f6nceki nesildekinden daha az miktarda allel yeni nesillere aktar\u0131lm\u0131\u015f olur. Bu da aktar\u0131lan allellerin say\u0131s\u0131n\u0131n bir \u00f6nceki nesle g\u00f6re azalmas\u0131na ve s\u0131kl\u0131klar\u0131n\u0131n artmas\u0131na sebep olur. Bu durumda, genetik s\u00fcr\u00fcklenme \u00e7e\u015fitlili\u011fin azalmas\u0131na sebep olur.<\/p>\n

Genetik \u00e7e\u015fitlili\u011fin azalmas\u0131, pop\u00fclasyon boyutunun herhangi bir nedene ba\u011fl\u0131 olarak h\u0131zla k\u00fc\u00e7\u00fclmesi yoluyla da ger\u00e7ekle\u015febilir. \u00d6zellikle insan pop\u00fclasyonlar\u0131n\u0131n \u015fekillenmesinde, darbo\u011faz<\/strong> ve kurucu<\/strong> etkileri \u00f6nemli rol oynar.<\/p>\n

\"\"\u0130nsan pop\u00fclasyonlar\u0131n\u0131n genetik \u00f6zelliklerinin \u00e7e\u015fitlenmesinde en \u00f6nemli etkilerden biri de g\u00f6\u00e7<\/strong>t\u00fcr. G\u00f6\u00e7, pop\u00fclasyonlar\u0131n \u00e7e\u015fitli co\u011frafyalar aras\u0131ndaki hareketleridir. G\u00f6\u00e7\u00fcn insan pop\u00fclasyonlar\u0131n\u0131n geneti\u011fine etkisi a\u00e7\u0131s\u0131ndan birden fazla bi\u00e7imi vard\u0131r ve bunlar genellikle literat\u00fcrde birbirlerinin yerine kullan\u0131ld\u0131\u011f\u0131ndan karma\u015faya yol a\u00e7ar.1<\/sup><\/p>\n

E\u011fer g\u00f6\u00e7, daha \u00f6nce insan t\u00fcr\u00fcn\u00fcn bulunmad\u0131\u011f\u0131 bir co\u011frafyaya hareket \u015fekilde ger\u00e7ekle\u015ftiyse bu kolonizasyon<\/strong> olarak adland\u0131r\u0131l\u0131r. Burada genetik a\u00e7\u0131dan s\u00f6z konusu olan, kurucu etkisidir. Daha \u00f6nce burada, insan pop\u00fclasyonlar\u0131na ait bir genetik karakter bulunmad\u0131\u011f\u0131ndan, yerle\u015fen yeni pop\u00fclasyonun s\u0131n\u0131rl\u0131 genetik kayna\u011f\u0131, yeni pop\u00fclasyonun \u015fekillenmesinde kurucu bir etkiye sahip olacakt\u0131r. Bu pop\u00fclasyon, daha \u00f6nce ayr\u0131ld\u0131\u011f\u0131 pop\u00fclasyondaki t\u00fcm genetik karakterleri ta\u015f\u0131yamayaca\u011f\u0131 i\u00e7in, yeni co\u011frafyada genetik \u00e7e\u015fitlilik bir \u00f6ncekine g\u00f6re azalm\u0131\u015f olur. Kolonizasyon, insanl\u0131k tarihinde birden fazla kez ger\u00e7ekle\u015fmi\u015ftir. \u0130lk olarak, Homo sapiens<\/em>\u2019in Afrika\u2019dan \u00e7\u0131k\u0131\u015f\u0131 bu duruma \u00f6rnek olarak g\u00f6sterilebilir. Bug\u00fcn h\u00e2l\u00e2 Afrika\u2019daki genetik \u00e7e\u015fitlilik di\u011fer co\u011frafyalara g\u00f6re daha fazlad\u0131r.4<\/sup> Bir di\u011fer \u00f6rnek ise yakla\u015f\u0131k 15 bin y\u0131l \u00f6nce Bering Bo\u011faz\u0131\u2019ndan Amerika k\u0131tas\u0131na ge\u00e7i\u015ftir.<\/p>\n

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Afrika\u2019dan \u00e7\u0131k\u0131\u015f\u0131n hemen ard\u0131ndan Homo sapiens ile Neandertal aras\u0131nda gen ak\u0131\u015f\u0131 ger\u00e7ekle\u015fti.<\/figcaption><\/figure>\n

Bir di\u011fer g\u00f6\u00e7 bi\u00e7imi ise, daha \u00f6nce insanlar taraf\u0131ndan h\u00e2lihaz\u0131rda yerle\u015filmi\u015f co\u011frafyalara kitlesel harekettir. Bu t\u00fcr g\u00f6\u00e7 bi\u00e7iminde, g\u00f6\u00e7 alan ve g\u00f6\u00e7 eden iki farkl\u0131 pop\u00fclasyon bulunur ve bu pop\u00fclasyonlar aras\u0131nda gen ak\u0131\u015f\u0131 ger\u00e7ekle\u015fir. Bu gen ak\u0131\u015f\u0131 \u00e7e\u015fitlili\u011fi art\u0131ran bir fakt\u00f6r olarak rol oynar.\u00a0 Mutasyon, rekombinasyon ve genetik s\u00fcr\u00fcklenmenin aksine g\u00f6\u00e7, \u00e7o\u011funlukla pop\u00fclasyonlar aras\u0131 de\u011fil, pop\u00fclasyon i\u00e7i allel s\u0131kl\u0131klar\u0131nda de\u011fi\u015fime yol a\u00e7ar.1<\/sup> \u0130ngiltere\u2019ye MS 400\u2019lerde ger\u00e7ekle\u015fen Anglosakson g\u00f6\u00e7leri bu duruma \u00f6rnek g\u00f6sterilebilir.5<\/sup><\/p>\n

\u0130nsan\u0131n genetik tarihi<\/strong><\/p>\n

Modern insan\u0131n k\u00f6keni, bir\u00e7ok bilim dal\u0131n\u0131n ortak \u00e7al\u0131\u015fmas\u0131yla belirlenebilmektedir. \u00d6nceleri bir\u00e7ok farkl\u0131 g\u00f6r\u00fc\u015f ortaya at\u0131lm\u0131\u015f olsa da bug\u00fcn modern insan\u0131n Afrika\u2019da g\u00fcn\u00fcm\u00fczden yakla\u015f\u0131k 200 bin y\u0131l \u00f6nce ortaya \u00e7\u0131kt\u0131\u011f\u0131 ve gezegenin di\u011fer b\u00f6lgelerine yay\u0131ld\u0131\u011f\u0131 bilim d\u00fcnyas\u0131 taraf\u0131ndan kabul edilmektedir.6<\/sup> (Tablo 1) Antropolojik, morfolojik, genetik ve linguistik \u00e7al\u0131\u015fmalar\u0131, Homo sapiens<\/em>\u2019in D\u00fcnya \u00fczerindeki yolculu\u011funu ve evrimsel a\u00e7\u0131dan yak\u0131n akrabalar\u0131yla ili\u015fkilerini incelemeye devam etmektedir.<\/p>\n

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Tablo 1. \u0130nsan\u0131n k\u0131sa tarihi(1)<\/figcaption><\/figure>\n

20. y\u00fczy\u0131lda genetik biliminin geli\u015fmesi, insan\u0131n evrimsel tarihine ili\u015fkin \u00e7al\u0131\u015fmalarda yeni bir kap\u0131 aralam\u0131\u015ft\u0131r. Bu anlamda ilk geni\u015f \u00f6l\u00e7ekli \u00e7al\u0131\u015fma, 1987 y\u0131l\u0131nda Rebecca Cann ve arkada\u015flar\u0131n\u0131n, 147 bireye ait mitokondriyal genomu incelemesidir. \u00c7al\u0131\u015fma, ya\u015fayan t\u00fcm insanlar\u0131n mitokondriyal k\u00f6keninin Afrika\u2019ya dayand\u0131\u011f\u0131n\u0131 g\u00f6stermi\u015ftir.7<\/sup> Bu \u00e7al\u0131\u015fman\u0131n sonu\u00e7lar\u0131, o g\u00fcnlerde h\u00e2l\u00e2 tart\u0131\u015fmal\u0131 bir konu olan insan\u0131n k\u00f6kenine dair \u00f6nemli bir bak\u0131\u015f a\u00e7\u0131s\u0131 sa\u011flamas\u0131 a\u00e7\u0131s\u0131ndan \u00f6nem ta\u015f\u0131r.<\/p>\n

Ayn\u0131 y\u0131llarda, organizman\u0131n canl\u0131l\u0131\u011f\u0131n\u0131n sonlanmas\u0131ndan sonra baz\u0131 dokularda DNA\u2019n\u0131n korunabilece\u011fi fikri ortaya at\u0131lm\u0131\u015f ve ilk antik DNA \u00e7al\u0131\u015fmalar\u0131 sonu\u00e7 vermeye ba\u015flam\u0131\u015ft\u0131r. 1990\u2019lar\u0131n ortalar\u0131nda Homo neanderthalis<\/em>\u2019e ait ilk DNA par\u00e7as\u0131 dizilenerek, soyu t\u00fckenmi\u015f en yak\u0131n insan t\u00fcr\u00fc olan Neandertal hakk\u0131nda, genetik veriler elde edilebilece\u011fi g\u00f6sterilmi\u015ftir.8<\/sup> Ayn\u0131 d\u00f6nemlerde \u0130nsan Genom Projesi (\u0130GP) de h\u0131z kazanm\u0131\u015f ve 2000\u2019lerin ba\u015f\u0131nda ilk sonu\u00e7lar\u0131 a\u00e7\u0131klanm\u0131\u015ft\u0131r. \u0130GP\u2019nin ba\u015far\u0131labilmesi i\u00e7in gereken teknolojinin k\u00fcm\u00fclatif bir \u015fekilde geli\u015fmesi, t\u00fcm genetik \u00e7al\u0131\u015fmalar\u0131nda k\u00f6\u015fe ta\u015f\u0131 olarak de\u011ferlendirilmektedir. 2010 itibariyle, art\u0131k bir\u00e7ok t\u00fcr\u00fcn genomu dizilenmi\u015f ve geli\u015ftirilen farkl\u0131 yakla\u015f\u0131klarla bu genomlar analiz edilebilir hale gelmi\u015ftir.<\/p>\n

T\u00fcm bu geli\u015fmeler \u0131\u015f\u0131\u011f\u0131nda, 2010 y\u0131l\u0131nda ilk Neandertal taslak genomu yay\u0131nlanm\u0131\u015ft\u0131r.9<\/sup> Bu \u00e7al\u0131\u015fma, morfolojik yollarla elde edilemeyen birtak\u0131m \u00f6nemli sonu\u00e7lar\u0131 bilim d\u00fcnyas\u0131n\u0131n ilgisine sunmu\u015ftur. Daha \u00f6nceleri Neandertallerle modern insan aras\u0131nda gen ak\u0131\u015f\u0131 olmad\u0131\u011f\u0131 d\u00fc\u015f\u00fcn\u00fcl\u00fcrken,10<\/sup> bu \u00e7al\u0131\u015fman\u0131n en \u00f6nemli ve dikkat \u00e7eken sonu\u00e7lar\u0131ndan biri, bug\u00fcn Afrika d\u0131\u015f\u0131nda ya\u015fayan insanlar\u0131n genomunun farkl\u0131 b\u00f6lgelerinde Neandertallere ait bir miktar DNA par\u00e7as\u0131n\u0131n bulundu\u011funun belirlenmesidir.<\/p>\n

Bu \u00e7al\u0131\u015fman\u0131n hemen ard\u0131ndan Sibirya\u2019daki Denisovan Ma\u011faras\u0131\u2019nda yap\u0131lan arkeolojik \u00e7al\u0131\u015fmalar s\u0131ras\u0131nda bulunan, bir hominine ait parmak ve di\u015f fosillerinden s\u00f6z konusu homininin genomu dizilenmi\u015ftir.11<\/sup> Bu bireye ait tan\u0131mlay\u0131c\u0131 bir iskelet par\u00e7as\u0131 bulunamad\u0131\u011f\u0131ndan hangi t\u00fcre ait oldu\u011fu morfolojik \u00e7al\u0131\u015fmalarla belirlenememi\u015ftir. Genomunun dizilenmesiyle yeni bir hominin t\u00fcr\u00fc oldu\u011fu belirlenmi\u015f ve Denisovan ismi verilmi\u015ftir. N\u00fckleer genom \u00e7e\u015fitlili\u011finin Neandertallerden daha fazla, modern insandan daha az oldu\u011fu belirlenmi\u015ftir.12<\/sup> Dahas\u0131, Malinezya ve Okyanusya\u2019da ya\u015fayan pop\u00fclasyonlar\u0131n bir k\u0131sm\u0131n\u0131n, genomunda Denisovan\u2019a ait DNA par\u00e7alar\u0131 ta\u015f\u0131d\u0131\u011f\u0131 tespit edilmi\u015ftir.13<\/sup> (\u015eekil 1)<\/p>\n

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1. Arkaik homininlerden modern insana gen ak\u0131\u015f \u015femas\u0131.(11)<\/figcaption><\/figure>\n

Ayn\u0131 d\u00f6nemde, son y\u0131llar\u0131n insan evrimsel geneti\u011fi a\u00e7\u0131s\u0131ndan, yap\u0131lan en b\u00fcy\u00fck projelerden biri olan 1000 Genom Projesi ba\u015flam\u0131\u015ft\u0131r. S\u00f6z konusu projenin ilk faz\u0131yla birlikte insan\u0131n pop\u00fclasyon tarihi ayr\u0131nt\u0131l\u0131 bir bi\u00e7imde ortaya \u00e7\u0131kmaya ba\u015flam\u0131\u015f, sonu\u00e7lara g\u00f6re, \u00e7e\u015fitlili\u011fin en fazla Afrika\u2019da, onu takiben Avrupa ve Asya\u2019da oldu\u011fu anla\u015f\u0131lm\u0131\u015ft\u0131r.4<\/sup> \u0130nsan\u0131n Afrika\u2019da, di\u011fer k\u0131talara yay\u0131lmadan \u00f6nce ge\u00e7irdi\u011fi s\u00fcre g\u00f6z \u00f6n\u00fcnde bulunduruldu\u011funda bu sonu\u00e7 olduk\u00e7a anlaml\u0131d\u0131r. Daha \u00f6nce de s\u00f6z edildi\u011fi gibi, g\u00f6\u00e7 s\u0131ras\u0131nda var olan t\u00fcm genetik \u00e7e\u015fitlilik g\u00f6\u00e7 edilen b\u00f6lgeye ta\u015f\u0131namayaca\u011f\u0131ndan, di\u011fer k\u0131talarda \u00e7e\u015fitlili\u011fin g\u00f6rece az olmas\u0131 beklenen bir sonu\u00e7 olarak de\u011ferlendirilebilir. 2015 y\u0131l\u0131nda sonlanan bu projenin sonucunda, be\u015f k\u0131tadan 2504 bireye ait genom dizilenmi\u015f, elde edilen verilerle insan pop\u00fclasyonunun genetik haritas\u0131 olu\u015fturulmu\u015ftur.14<\/sup> Veriler \u00fczerinde analizler devam etmektedir.<\/p>\n

Yap\u0131lan \u00e7al\u0131\u015fmalar\u0131n sonu\u00e7lar\u0131 bir araya getirildi\u011finde insan\u0131n k\u0131sa tarihi \u015fu \u015fekilde \u00f6zetlenebilir:<\/p>\n

– \u0130nsans\u0131lar yakla\u015f\u0131k 7 milyon y\u0131l \u00f6nce \u015fempanzenin ortak atalar\u0131ndan ayr\u0131lm\u0131\u015ft\u0131r.<\/p>\n

– Yakla\u015f\u0131k 1 milyon y\u0131l \u00f6nce Neandertal ve modern insan\u0131n atalar\u0131, Denisovan\u2019\u0131n atalar\u0131ndan ayr\u0131lm\u0131\u015ft\u0131r.<\/p>\n

– Homo sapiens <\/em>ve Neandertal\u2019in ortak atalar\u0131 yakla\u015f\u0131k 460 bin y\u0131l \u00f6nce ayr\u0131lm\u0131\u015ft\u0131r.<\/p>\n

– Homo sapiens <\/em>yakla\u015f\u0131k 200 bin y\u0131l \u00f6nce Afrika\u2019da ortaya \u00e7\u0131km\u0131\u015ft\u0131r.<\/p>\n

– Yakla\u015f\u0131k 90-120 bin y\u0131l \u00f6nce Arap Yar\u0131madas\u0131\u2019na ge\u00e7erek Afrika\u2019dan ilk kez \u00e7\u0131km\u0131\u015f, ancak bu g\u00f6\u00e7 di\u011fer k\u0131talara yay\u0131lamam\u0131\u015ft\u0131r.<\/p>\n

– Yakla\u015f\u0131k 50-70 bin y\u0131l \u00f6nce tekrar Afrika\u2019dan \u00e7\u0131kan modern insan, di\u011fer Eski D\u00fcnya k\u0131talar\u0131na yay\u0131lmaya ba\u015flay\u0131p, ~40 bin y\u0131l \u00f6nce Avustralya\u2019ya ula\u015fm\u0131\u015ft\u0131r.<\/p>\n

– Afrika\u2019dan \u00e7\u0131k\u0131\u015f\u0131n hemen ard\u0131ndan Homo sapiens<\/em> ile Neandertal aras\u0131nda gen ak\u0131\u015f\u0131 ger\u00e7ekle\u015fmi\u015ftir. Bu nedenle, bug\u00fcn Afrika d\u0131\u015f\u0131nda ya\u015fayan pop\u00fclasyonlarda ~%1-4 oran\u0131nda Neandertal DNA\u2019s\u0131 g\u00f6zlenmektedir.<\/p>\n

– Avrupa\u2019ya giden g\u00f6\u00e7 yolu ile Asya\u2019ya giden grup ayr\u0131\u015ft\u0131ktan bir s\u00fcre sonra, tahminlere g\u00f6re G\u00fcneydo\u011fu Asya\u2019da modern insan ile Denisovan aras\u0131nda gen ak\u0131\u015f\u0131 ger\u00e7ekle\u015fmi\u015ftir. Bunun sonucu olarak baz\u0131 Malinezya ve Okyanusya pop\u00fclasyonlar\u0131n\u0131n genomunda ~%4-7 oran\u0131nda Denisovan katk\u0131s\u0131 tespit edilmi\u015ftir.<\/p>\n

– Daha yak\u0131n bir tarihte, ~15 bin y\u0131l \u00f6nce Sibirya ile Amerika aras\u0131nda, o d\u00f6nemler kara k\u00f6pr\u00fcs\u00fc olan Bering Bo\u011faz\u0131\u2019ndan Amerika\u2019ya ge\u00e7i\u015fler ba\u015flam\u0131\u015ft\u0131r. Son yap\u0131lan \u00e7al\u0131\u015fmalar, burada farkl\u0131 zamanlarda birden fazla g\u00f6\u00e7\u00fcn ger\u00e7ekle\u015fti\u011fini, en az iki farkl\u0131 kurucu pop\u00fclasyon oldu\u011funu g\u00f6stermektedir.15<\/sup><\/p>\n

T\u00fcm bu sonu\u00e7lar, genetik \u00e7al\u0131\u015fmalarla birlikte, arkeolojik ve linguistik bulgularla da desteklenmektedir. \u00d6zellikle linguistik evrimin izi s\u00fcr\u00fclerek yap\u0131lan \u00e7al\u0131\u015fmalar, genetik kay\u0131tlarla \u00f6rt\u00fc\u015fmektedir.16<\/sup><\/p>\n

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Modern insan genomunda arkaik kal\u0131nt\u0131lara ait en \u00f6nemli \u00f6rneklerden biri Tibetlilerde bulunan Denisovan benzeri b\u00f6lgelerdir.<\/figcaption><\/figure>\n

Modern insan ile arkaik homininlerin kar\u0131\u015fmas\u0131<\/strong><\/p>\n

Neandertal ve modern insan\u0131n atalar\u0131n\u0131n ayr\u0131\u015fmas\u0131ndan sonra, iklim de\u011fi\u015fimlerinin de etkisiyle Afrika ve Avrupa pop\u00fclasyonlar\u0131n\u0131n aras\u0131nda meydana gelen co\u011frafi izolasyon, bu iki pop\u00fclasyonun t\u00fcrle\u015fmesinde b\u00fcy\u00fck rol oynam\u0131\u015ft\u0131r. B\u00f6ylece, Avrupa\u2019da t\u00fcrle\u015fen Neandertallerle Afrika\u2019dan hen\u00fcz \u00e7\u0131kmam\u0131\u015f olan Homo sapiens<\/em> aras\u0131nda uzunca bir s\u00fcre etkile\u015fim ger\u00e7ekle\u015fmemi\u015ftir. Modern insan\u0131n Afrika\u2019dan \u00e7\u0131kmas\u0131yla ilk kar\u015f\u0131la\u015fman\u0131n Orta Do\u011fu\u2019da ger\u00e7ekle\u015fti\u011fi d\u00fc\u015f\u00fcn\u00fclmektedir. Ortaya at\u0131lan bu sav\u0131n en \u00f6nemli dayana\u011f\u0131, bug\u00fcn Afrika d\u0131\u015f\u0131nda ya\u015fayan neredeyse t\u00fcm pop\u00fclasyonlarda \u00e7e\u015fitli oranlarda Neandertal DNA\u2019s\u0131 tespit edilmi\u015f olmas\u0131d\u0131r. Yap\u0131lan \u00e7al\u0131\u015fmalarda s\u00f6z konusu ilk kar\u015f\u0131la\u015fma ve kar\u0131\u015fman\u0131n, yakla\u015f\u0131k 47-65 bin y\u0131l \u00f6nce ger\u00e7ekle\u015fti\u011fi d\u00fc\u015f\u00fcn\u00fclse de son yap\u0131lan \u00e7al\u0131\u015fmalar ilk kar\u015f\u0131la\u015fman\u0131n tahmin edilenden binlerce y\u0131l \u00f6nce ger\u00e7ekle\u015fti\u011fini g\u00f6stermektedir.17<\/sup> Orta Do\u011fu\u2019dan d\u00fcnyan\u0131n geri kalan\u0131na yay\u0131lan modern insana, hen\u00fcz b\u00f6lgeden \u00e7\u0131kmadan Neandertallerden gen ak\u0131\u015f\u0131n\u0131n ger\u00e7ekle\u015fti\u011fi d\u00fc\u015f\u00fcn\u00fclmektedir.<\/p>\n

Hen\u00fcz yeni yap\u0131lan, Avrupa\u2019n\u0131n genetik tarihini ayd\u0131nlatmaya y\u00f6nelik bir antik DNA \u00e7al\u0131\u015fmas\u0131nda,18<\/sup> ara\u015ft\u0131r\u0131c\u0131lar Avrupa\u2019da ~45 bin ila ~7 bin y\u0131l \u00f6nce ya\u015fam\u0131\u015f olan modern insan genomlar\u0131n\u0131 inceleyerek Neandertal katk\u0131s\u0131n\u0131n de\u011fi\u015fimini incelediler. \u00c7al\u0131\u015fman\u0131n sonu\u00e7lar\u0131na g\u00f6re, modern insandaki Neandertal katk\u0131s\u0131 y\u0131llar i\u00e7erisinde anlaml\u0131 bir d\u00fc\u015f\u00fc\u015f g\u00f6stermektedir. (\u015eekil 2) Bunun nedeni do\u011fal se\u00e7ilimin genel anlamda Neandertal k\u00f6kenli genlerin aleyhine \u00e7al\u0131\u015fmas\u0131 olabilir. \u00d6rne\u011fin, yak\u0131n zamanda yap\u0131lan Neandertallere ait Y kromozomunun dizilendi\u011fi ba\u015fka bir \u00e7al\u0131\u015fmada, modern insan\u0131n Y kromozomunda Neandertal katk\u0131s\u0131na rastlanmam\u0131\u015ft\u0131r.19<\/sup> Bu da \u00f6zellikle modern insana \u00f6zg\u00fc, \u201cinsan\u0131 insan yapan\u201d gen b\u00f6lgelerindeki arkaik katk\u0131lar\u0131n genomda bar\u0131namad\u0131\u011f\u0131n\u0131 g\u00f6stermesi a\u00e7\u0131s\u0131ndan \u00f6nemlidir.<\/p>\n

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\u015eekil 2. Modern insanda zaman i\u00e7erisinde de\u011fi\u015fen Neandertal katk\u0131s\u0131 (18)<\/figcaption><\/figure>\n

Benzer bi\u00e7imde, Malinezya ve Okyanusya pop\u00fclasyonlar\u0131, Denisovan\u2019a ait DNA par\u00e7alar\u0131 ta\u015f\u0131maktad\u0131r. Ancak Denisovanlara dair bulunan fosiller hen\u00fcz s\u0131n\u0131rl\u0131 miktarda oldu\u011fundan yeterli \u00e7al\u0131\u015fma yap\u0131lamam\u0131\u015f, t\u00fcr\u00fcn genetik \u00e7e\u015fitlili\u011fi tam olarak bilinemedi\u011finden pop\u00fclasyon tarihi ortaya konamam\u0131\u015ft\u0131r. Bu nedenle, en \u00f6nemli \u00f6rneklerine Sibirya\u2019da rastlanan bu t\u00fcr\u00fcn, modern insanla nerede kar\u015f\u0131la\u015ft\u0131\u011f\u0131 hen\u00fcz tart\u0131\u015fma konusudur. Sadece Malinezya ve Okyanusya pop\u00fclasyonlar\u0131nda Denisovan katk\u0131s\u0131n\u0131n g\u00f6r\u00fclmesi, bu b\u00f6lgeye yerle\u015fmeden hemen \u00f6nce, tahminen G\u00fcneydo\u011fu Asya\u2019da kar\u015f\u0131la\u015ft\u0131klar\u0131n\u0131 d\u00fc\u015f\u00fcnd\u00fcrmektedir.<\/p>\n

Arkaik homininlerden modern insana gen ak\u0131\u015f\u0131n\u0131n oldu\u011fu belirlendikten sonra, akla gelen en \u00f6nemli sorulardan biri, bu DNA par\u00e7alar\u0131n\u0131n modern insan genomuna da\u011f\u0131l\u0131m \u00f6r\u00fcnt\u00fcs\u00fcne ili\u015fkindi. Daha \u00f6nce DNA par\u00e7alar\u0131n\u0131n bir k\u0131sm\u0131n\u0131n genomdan at\u0131ld\u0131\u011f\u0131n\u0131 belirtmi\u015ftik. Buna ra\u011fmen yap\u0131lan baz\u0131 \u00e7al\u0131\u015fmalar ge\u00e7en genlerin bir k\u0131sm\u0131n\u0131n pozitif do\u011fal se\u00e7ilime u\u011frad\u0131\u011f\u0131n\u0131 ve pop\u00fclasyonlarda birtak\u0131m fenotipik \u00f6zellikler \u00fczerinde etkili oldu\u011funu g\u00f6stermi\u015ftir. Bu do\u011fal se\u00e7ilim, patojen, diyet, sosyal organizasyon veya yeni co\u011frafyalara adaptasyon gibi \u00e7evresel \u00f6zelliklere ba\u011fl\u0131 olarak ger\u00e7ekle\u015fmi\u015ftir.<\/p>\n

Yap\u0131lan ilk \u00f6nemli \u00e7al\u0131\u015fmalardan birinde,20<\/sup> ba\u011f\u0131\u015f\u0131kl\u0131k sistemi resept\u00f6rlerinin olu\u015fumunda rol oynayan HLA<\/em> geninin Neandertal ve Denisovan allellerinden etkilendi\u011fi bildirilmi\u015ftir. MHC (Major histocompatibility complex) ailesine ait olan ve y\u00fcksek oranda polimorfizm g\u00f6steren HLA-A<\/em>, HLA-B<\/em> ve HLA-C<\/em> genlerinin co\u011frafi da\u011f\u0131l\u0131m\u0131 incelendi\u011finde, \u00f6zellikle HLA-B*73 <\/em>allelinin Afrika pop\u00fclasyonlar\u0131nda bulunmad\u0131\u011f\u0131, frekans\u0131n\u0131n Bat\u0131 Asya\u2019da yo\u011funla\u015ft\u0131\u011f\u0131 ve di\u011fer b\u00f6lgelerde g\u00f6rece daha ender rastland\u0131\u011f\u0131 tespit edilmi\u015ftir. Benzer \u015fekilde, HLA-A <\/em>ve C <\/em>genlerine ait Denisovan\u2019da bulunan baz\u0131 allellerin Malinezya ve Papua Yeni Gine pop\u00fclasyonlar\u0131nda s\u0131kl\u0131kla g\u00f6r\u00fcld\u00fc\u011f\u00fc belirlenmi\u015ftir. Ba\u015fka bir \u00e7al\u0131\u015fmada, yine bir ba\u011f\u0131\u015f\u0131kl\u0131k sistemi geni olan STAT2<\/em> gen b\u00f6lgesinde arkaik izlere rastlanm\u0131\u015ft\u0131r.21<\/sup><\/p>\n

Arkaik homininlere ait ba\u011f\u0131\u015f\u0131kl\u0131k sistemi allellerinin se\u00e7ilimi, Afrika\u2019da bulunan patojenlere kar\u015f\u0131 ba\u011f\u0131\u015f\u0131kl\u0131k sistemi \u015fekillenmi\u015f olan modern insan\u0131n, g\u00f6\u00e7 etti\u011finde kar\u015f\u0131la\u015ft\u0131\u011f\u0131 yeni patojenlere adaptasyonunu sa\u011flam\u0131\u015ft\u0131r. Bu adaptasyonun insanl\u0131k tarihi a\u00e7\u0131s\u0131ndan \u00f6nemi olduk\u00e7a b\u00fcy\u00fckt\u00fcr, zira daha sonralar\u0131 ba\u011f\u0131\u015f\u0131kl\u0131k sistemini y\u00f6neten ba\u015fka gen b\u00f6lgesinde de arkaik hominin katk\u0131s\u0131 bildirilmi\u015ftir.22\u201324<\/sup> Bu \u00e7al\u0131\u015fmalar, ba\u011f\u0131\u015f\u0131kl\u0131k sistemi yolaklar\u0131n\u0131n nas\u0131l \u00e7al\u0131\u015ft\u0131\u011f\u0131n\u0131 ve ba\u011f\u0131\u015f\u0131kl\u0131k sisteminin evrimini anlamak i\u00e7in elzemdir. Ayn\u0131 zamanda birtak\u0131m hastal\u0131klar\u0131n fenotipinde de\u011fi\u015fikli\u011fe yol a\u00e7t\u0131\u011f\u0131ndan,23<\/sup> modern insanda arkaik genom par\u00e7alar\u0131n\u0131 ara\u015ft\u0131rmak bu hastal\u0131klar\u0131n da anla\u015f\u0131lmas\u0131n\u0131 sa\u011flar.<\/p>\n

Neandertal benzeri b\u00f6lgeler (NLS) i\u00e7eren bir ba\u015fka gen grubu lipit katabolizmas\u0131n\u0131 d\u00fczenleyen gen b\u00f6lgeleridir.25<\/sup> Neandertal benzeri b\u00f6lgeler, t\u00fcm Afrika-d\u0131\u015f\u0131 pop\u00fclasyonlarda bulunsa da Avrupal\u0131 pop\u00fclasyonlar\u0131n lipit katabolizmas\u0131yla ili\u015fkili genlerinde yakla\u015f\u0131k \u00fc\u00e7 kat daha fazlad\u0131r. Asya\u2019da bu allellerin s\u0131n\u0131rl\u0131 olmas\u0131, Avrupa\u2019n\u0131n tarih \u00f6ncesi \u00e7evresel ko\u015fullar\u0131na uyum i\u00e7in bu genlerin etkisinin \u00f6nemli oldu\u011funu g\u00f6stermektedir. Dahas\u0131, NLS i\u00e7eren allellerin obezite, diyabet gibi kimi hastal\u0131klar\u0131n Avrupal\u0131 fenotipinde etkili oldu\u011fu bildirilmi\u015ftir. Benzer bir durum, Sibirya\u2019da ya\u015fayan Ket pop\u00fclasyonunda da g\u00f6zlenmi\u015f, et a\u011f\u0131rl\u0131kl\u0131 beslenen bu pop\u00fclasyonun aminoasit metabolizmas\u0131nda rol oynayan baz\u0131 allellerinde Neandertal katk\u0131s\u0131 bulunmu\u015ftur.26<\/sup><\/p>\n

\"\"Modern insan genomunda arkaik kal\u0131nt\u0131lara ait en \u00f6nemli \u00f6rneklerden bir di\u011feri Tibetlilerde bulunan Denisovan benzeri b\u00f6lgelerdir. Y\u00fcksek rak\u0131mlarda bulunan yerle\u015fim b\u00f6lgelerinin oksijence fakir oldu\u011fu bilinmektedir. Bu b\u00f6lgelerde k\u0131sa s\u00fcreli bulunan insanlarda hemoglobin miktar\u0131n\u0131n artmas\u0131 bilinen bir modifikasyon t\u00fcr\u00fcd\u00fcr. Yakla\u015f\u0131k 4 bin metre y\u00fckseklikteki Tibet platosunda ya\u015fayan pop\u00fclasyonda durum bundan farkl\u0131d\u0131r. Deniz seviyesine g\u00f6re % 40 daha az oksijen ihtiva etmesine ra\u011fmen, Tibetli pop\u00fclasyonlardaki hemoglobin art\u0131\u015f\u0131 olduk\u00e7a s\u0131n\u0131rl\u0131d\u0131r.27<\/sup> Hemoglobin art\u0131\u015f\u0131n\u0131n, ayn\u0131 zamanda kan\u0131n yo\u011funlu\u011funu art\u0131rmas\u0131 ve birtak\u0131m kardiyak hastal\u0131klara yol a\u00e7mas\u0131 bu duruma neden olarak g\u00f6sterilmektedir.<\/p>\n

T\u00fcm bunlardan yola \u00e7\u0131k\u0131larak yap\u0131lan bir \u00e7al\u0131\u015fmada28<\/sup> EPAS1 <\/em>geninin haplotipinin Tibetli pop\u00fclasyonda, d\u00fcnyan\u0131n di\u011fer b\u00f6lgelerindeki haplotiplerden olduk\u00e7a farkl\u0131 oldu\u011fu tespit edilmi\u015ftir. S\u00f6z konusu haplotipin Tibetliler haricinde, sadece Denisovan\u2019da ve \u00e7ok az miktarda Han \u00c7inlileri\u2019nde bulundu\u011fu saptanm\u0131\u015ft\u0131r. Bu durum, Han \u00c7inlileri ile Tibetlilerin ayr\u0131\u015fma tarihinden \u00f6nceki bir tarihte Denisovan ile gen ak\u0131\u015f\u0131n\u0131n ger\u00e7ekle\u015fti\u011fini ve y\u00fcksek rak\u0131ma adaptasyon anlam\u0131nda avantaj sa\u011flayan EPAS1 <\/em>geninin do\u011fal se\u00e7ilim yoluyla Tibetlilerde frekans\u0131n\u0131n artt\u0131\u011f\u0131n\u0131 g\u00f6stermektedir.<\/p>\n

Modern insan genomunda Neandertal katk\u0131s\u0131n\u0131 geni\u015f \u00f6l\u00e7ekte inceleyen bir ba\u015fka \u00e7al\u0131\u015fmada,29<\/sup> keratin filamentlerini etkileyen genlerde pozitif se\u00e7ilime rastlanm\u0131\u015ft\u0131r. Ayn\u0131 \u00e7al\u0131\u015fmada, Neandertal\u2019den ge\u00e7ti\u011fi d\u00fc\u015f\u00fcn\u00fclen genlerin, testislerdeki anlat\u0131m\u0131nda anlaml\u0131 derecede d\u00fc\u015f\u00fc\u015f g\u00f6zlemlendi\u011fi, X kromozomunda genomun di\u011fer b\u00f6lgelerine g\u00f6re 5 kat daha az bulunduklar\u0131 saptanm\u0131\u015ft\u0131r. Bu durum, Neandertal katk\u0131s\u0131n\u0131n do\u011furganl\u0131\u011f\u0131 etkiledi\u011fini g\u00f6stermesi bak\u0131m\u0131ndan \u00f6nemlidir.<\/p>\n

Sonu\u00e7 olarak, arkaik homininlerle modern insan\u0131n \u201cadaptif melezlenme\u201d ad\u0131 da verilen kar\u0131\u015fmas\u0131, birden fazla kez ger\u00e7ekle\u015fmi\u015f ve modern insan genomunda birden fazla b\u00f6lgeyi etkilemi\u015ftir. Adaptif melezlenme, ba\u011f\u0131\u015f\u0131kl\u0131k sistemi, pigmentasyon, y\u00fcksek rak\u0131ma uyum, birtak\u0131m metabolizma genleri ve karakterize edilmemi\u015f baz\u0131 fonksiyonlar\u0131 etkilemi\u015ftir.30<\/sup> Bu \u015fekilde, genetik \u00e7e\u015fitlili\u011fi art\u0131ran yeni bir kaynak olarak, modern insan\u0131n g\u00f6\u00e7 etti\u011fi yeni co\u011frafyalara uyum sa\u011flamas\u0131nda etkin rol oynam\u0131\u015ft\u0131r. \u0130nsan genomunda arkaik izlerin ara\u015ft\u0131r\u0131lmas\u0131nda yeni istatistiksel y\u00f6ntemlerin geli\u015ftirilmesiyle, bu \u00e7al\u0131\u015fmalar her ge\u00e7en g\u00fcn artmaktad\u0131r. Yeni yay\u0131nlanan genom verileri de s\u00f6z konusu kar\u0131\u015fma \u00f6r\u00fcnt\u00fclerini tespit etmek i\u00e7in \u00f6nemli bir kaynakt\u0131r. Bu b\u00f6lgelerin tam olarak haritalanmas\u0131, insanl\u0131k tarihinin yan\u0131nda hastal\u0131klar\u0131n molek\u00fcler tarihini ayd\u0131nlatmada da \u00f6nemli bir parametre olacakt\u0131r.<\/p>\n

\u0130nsan kar\u0131\u015fmalar\u0131 nas\u0131l belirleniyor?<\/strong><\/p>\n

\u0130nsan kar\u0131\u015f\u0131m \u00f6r\u00fcnt\u00fcleri, \u00e7ok say\u0131da insana ait genom kar\u015f\u0131la\u015ft\u0131r\u0131larak tespit edilir. Tek bir insan genomunun ~3,5 milyar baz \u00e7iftinden olu\u015ftu\u011fu d\u00fc\u015f\u00fcn\u00fcl\u00fcrse, b\u00f6ylesine b\u00fcy\u00fck bir verinin bilgisayar bilimleri olmadan analiz edilmesi d\u00fc\u015f\u00fcn\u00fclemez. Bu nedenle bir\u00e7ok bilim dal\u0131ndan ara\u015ft\u0131rmac\u0131lar\u0131n bir araya gelerek yapt\u0131klar\u0131 \u00e7al\u0131\u015fmalar sonucu, insanl\u0131k tarihi ara\u015ft\u0131rmalar\u0131nda kullan\u0131lmak \u00fczere birtak\u0131m istatistiksel y\u00f6ntemler ortaya \u00e7\u0131kt\u0131. Bu y\u00f6ntemler temelde, kar\u015f\u0131la\u015ft\u0131r\u0131lan genomlar\u0131n payla\u015ft\u0131klar\u0131 allellerin de\u011ferlendirilmesine dayan\u0131r, buradan pop\u00fclasyon d\u00fczeyinde sonu\u00e7lara ula\u015f\u0131l\u0131r. Bu ama\u00e7la kullan\u0131lan g\u00fcncel istatistiksel y\u00f6ntemler ve yaz\u0131l\u0131mlardan baz\u0131lar\u0131, D-testi, \u00fc\u00e7l\u00fc pop\u00fclasyon testi, ADMIXTURE analizi, fineSTRUCTURE, ender varyant analizi olarak s\u0131ralanabilir.<\/p>\n

Y\u00f6ntemlere dair ileri okumalar:<\/strong><\/p>\n

– Lawson, D. J., Hellenthal, G., Myers, S. & Falush, D. Inference of population structure using dense haplotype data. PLoS Genet.<\/em> 8, e1002453 (2012).<\/p>\n

– Patterson, N., et al.<\/em> Ancient admixture in human history. Genetics<\/em>, 192(3), 1065-1093. (2012).<\/p>\n

– Schiffels, S. et al.<\/em> Iron Age and Anglo-Saxon genomes from East England reveal British migration history. Nat. Commun.<\/em> 7, 10408 (2016).<\/p><\/blockquote>\n

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

1) Jobling, M., Hollox, E., Hurles, M., Kivisild, T. & Tyler-Smith, C. Human Evolutionary Genetics: Origins, Peoples & Disease<\/em>. (Garland Science, 2014).<\/p>\n

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14) Birney, E. & Soranzo, N. Human genomics: The end of the start for population sequencing. Nature<\/em> 526, 52\u201353 (2015).<\/p>\n

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16) Haak, W. et al.<\/em> Massive migration from the steppe was a source for Indo-European languages in Europe. Nature<\/em> 522, 207-211 (2015).<\/p>\n

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 <\/p>\n","protected":false},"excerpt":{"rendered":"

G\u00fcn\u00fcm\u00fcz verileriyle anatomik olarak modern insan\u0131n k\u00f6keni Afrika\u2019ya, 200 bin y\u0131l \u00f6ncesine dayan\u0131r. Homo sapiens\u2019in tarih sahnesine \u00e7\u0131kt\u0131\u011f\u0131nda, ya\u015fayan tek insan t\u00fcr\u00fc olmad\u0131\u011f\u0131 biliniyor. D\u00fcnya \u00fczerinde ge\u00e7irdi\u011fi 200 bin y\u0131l i\u00e7erisinde modern insan\u0131n, Homo neanderthalis ve Denisovan gibi arkaik homininler ile gen al\u0131\u015fveri\u015finde bulundu\u011fu ve kar\u0131\u015ft\u0131\u011f\u0131 tespit edildi. Bu gen ak\u0131\u015f\u0131, g\u00f6\u00e7 etti\u011fi b\u00f6lgelere uyum […]<\/p>\n","protected":false},"author":686,"featured_media":15432,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[185,211,21,1464,32,231],"tags":[200,292,497,230,1785,1660],"class_list":["post-15431","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-148-sayi","category-antropoloji","category-biyoloji","category-dosya","category-evrim","category-molekuler-biyoloji-ve-genetik","tag-evrim","tag-genetik","tag-homo-sapiens","tag-insanlik-tarihi","tag-populasyon","tag-turler"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t