Ara\u015ft\u0131rmac\u0131lar taraf\u0131ndan uzun zamand\u0131r g\u00f6z ard\u0131 edilen Afrika\u2019da biny\u0131llar \u00f6nce ya\u015fam\u0131\u015f insanlar\u0131n genomlar\u0131 sonunda incelenmeye ba\u015fland\u0131. 20 bireyin genomunun incelendi\u011fi iki ayr\u0131 projenin sonu\u00e7lar\u0131, ge\u00e7ti\u011fimiz hafta a\u00e7\u0131kland\u0131 ve t\u00fcr\u00fcm\u00fcz\u00fcn Afrika\u2019daki ge\u00e7mi\u015finin sand\u0131\u011f\u0131m\u0131zdan \u00e7ok daha karma\u015f\u0131k oldu\u011fu ortaya \u00e7\u0131kt\u0131.<\/p>\n
Afrika\u2019n\u0131n \u015fimdiye kadar antik-DNA ara\u015ft\u0131rmac\u0131lar\u0131 taraf\u0131ndan ihmal edilmesinin nedeniyse k\u0131tan\u0131n kavurucu iklimi. Y\u00fcksek s\u0131cakl\u0131klar DNA\u2019n\u0131n bozunmas\u0131n\u0131 h\u0131zland\u0131rd\u0131\u011f\u0131 i\u00e7in ara\u015ft\u0131rmac\u0131lar Avrupa\u2019daki daha serin b\u00f6lgelerden ve Sibirya\u2019daki donmu\u015f topraklardan elde edilen kal\u0131nt\u0131lar\u0131 sekanslamaya (dizilemeye) odaklanm\u0131\u015ft\u0131. Bu alanda Afrika\u2019daki ilk ba\u015far\u0131, 2015\u2019de ara\u015ft\u0131rmac\u0131lar Etiyopya\u2019da g\u00f6rece serin denilebilecek bir da\u011f ma\u011faras\u0131nda bulunan 4500 y\u0131ll\u0131k ya\u015fl\u0131 bir adam fosilinin genomunu sekanslad\u0131klar\u0131nda elde edildi.<\/p>\n
Fakat kontaminasyonu (elde edilen \u00f6rneklerin bakteri, kimyasal maddeler vs. ile kirlenmesi) temizleme konusunda sa\u011flanan ilerlemeler ve k\u00fc\u00e7\u00fck bir kulak kemi\u011finin antik DNA ile dolu oldu\u011funun ke\u015ffedilmesi, ara\u015ft\u0131rmac\u0131lar\u0131 teknolojinin art\u0131k Afrika\u2019n\u0131n ge\u00e7mi\u015fini ara\u015ft\u0131rmaya yeterli hale geldi\u011fine ikna etti.<\/p>\n
Jena, Almanya\u2019daki Max Planck \u0130nsan Tarihi Bilimi Enstit\u00fcs\u00fc\u2019nden pop\u00fclasyon genetik\u00e7isi Stephan Schiffels, ara\u015ft\u0131rmac\u0131lar\u0131n Avrasya\u2019daki antik insanlar hakk\u0131nda sahip olduklar\u0131 bilgi birikimine k\u0131yasla Sahra Alt\u0131 Afrika\u2019n\u0131n tarihine dair bilgi birikimimizin s\u0131n\u0131rl\u0131l\u0131\u011f\u0131n\u0131n utan\u00e7 verici oldu\u011funu s\u00f6yl\u00fcyor ve bu sebeple Afrika\u2019n\u0131n gizli kalm\u0131\u015f insan g\u00f6\u00e7\u00fc ge\u00e7mi\u015fini ortaya \u00e7\u0131karmak i\u00e7in DNA analizini kullanman\u0131n daha da \u00f6nemli hale geldi\u011fini ekliyor.<\/p>\n
Boston, Massachusetts\u2019teki Harvard T\u0131p Okulu\u2019ndan pop\u00fclasyon genetik\u00e7ileri Pontus Skoglund ve David Reich\u2019in \u00f6nderli\u011findeki bir grup biliminsan\u0131 da tam olarak bunu yap\u0131yor. Molek\u00fcler Biyoloji Toplulu\u011fu\u2019nun (Society forMolecular Biology<\/em>) 3 Temmuz\u2019da, Austin, Texas\u2019ta ger\u00e7ekle\u015fen y\u0131ll\u0131k toplant\u0131s\u0131nda Skoglund, kendi ekibinin 6000 y\u0131l kadar \u00f6nce Do\u011fu ve G\u00fcney Afrika\u2019da ya\u015fam\u0131\u015f 15 antik bireyin genomunu inceledi\u011fini a\u00e7\u0131klad\u0131. Bu bireylerden 11\u2019inin detayl\u0131 genetik analizini tamamlad\u0131klar\u0131n\u0131 da ekledi.<\/p>\n Eski Afrikal\u0131lar olduk\u00e7a hareketli<\/strong><\/p>\n Sonu\u00e7lara g\u00f6re antik insanlar k\u0131tan\u0131n \u00fczerinde san\u0131ld\u0131\u011f\u0131ndan \u00e7ok daha fazla yer de\u011fi\u015ftirdi. Tanzanya\u2019dan 3000 y\u0131l ya\u015f\u0131ndaki bir bireyin genomu hem Do\u011fru Afrikal\u0131 antik avc\u0131-toplay\u0131c\u0131lar\u0131n hem de Ortado\u011fu\u2019nun ilk \u00e7ift\u00e7ilerinin atalar\u0131na dair bilgiler sunuyor. Bu durum, daha \u00f6nceki \u00e7al\u0131\u015fmalarla ortaya \u00e7\u0131kar\u0131lan ve binlerce y\u0131l \u00f6nce ger\u00e7ekle\u015fti\u011fi d\u00fc\u015f\u00fcn\u00fclen \u201cAfrika\u2019ya geri d\u00f6n\u00fc\u015f\u201d g\u00f6\u00e7\u00fc fikrini destekliyor: Buradaki g\u00f6\u00e7ebeler Ortado\u011fu\u2019daki Levant b\u00f6lgesinde ya\u015fam\u0131\u015f olan eski \u00e7ift\u00e7ilerle yak\u0131n akraba.<\/p>\n Skoglund\u2019\u0131n aktard\u0131\u011f\u0131na g\u00f6re Tanzanya\u2019da bulunan fosil, ge\u00e7mi\u015fte hayvanc\u0131l\u0131k yap\u0131ld\u0131\u011f\u0131 d\u00fc\u015f\u00fcn\u00fclen bir arkeolojik alandan \u00e7\u0131kar\u0131ld\u0131 ve genetik olarak da g\u00fcn\u00fcm\u00fczde G\u00fcney Afrika\u2019da hayvanc\u0131l\u0131kla u\u011fra\u015fmakta olan insanlarla \u00e7e\u015fitli benzerlikler ta\u015f\u0131yor. Bu durum Do\u011fu Afrikal\u0131lar\u0131n hayvanc\u0131l\u0131\u011f\u0131 G\u00fcney Afrika\u2019ya ta\u015f\u0131d\u0131\u011f\u0131na i\u015faret ediyor.<\/p>\n Skoglund\u2019\u0131n ekibinin \u00fczerinde \u00e7al\u0131\u015fmakta oldu\u011fu hen\u00fcz yay\u0131mlanmam\u0131\u015f \u00e7al\u0131\u015fma daha fazla hareketlili\u011fe de i\u015faret ediyor. G\u00fcney Afrika\u2019dan 2000 y\u0131ll\u0131k bir bireyin genomu g\u00fcn\u00fcm\u00fczde de varl\u0131klar\u0131n\u0131 s\u00fcrd\u00fcren ve San\u2019lar olarak bilinen G\u00fcney Afrikal\u0131 avc\u0131-toplay\u0131c\u0131 insanlarla ortakl\u0131klar ta\u015f\u0131yor. Ayn\u0131 bireyin genomu, Malawi ve Tanzanya\u2019da bulunan ve avc\u0131-toplay\u0131c\u0131lara ait olan kal\u0131nt\u0131lardan elde edilen antik genomlarla da benzerlik ta\u015f\u0131yor, fakat Do\u011fu Afrika\u2019n\u0131n bug\u00fcnk\u00fc yerlileriyle bir ba\u011flant\u0131 bulunamam\u0131\u015f.<\/p>\n Skoglund\u2019\u0131n belirtti\u011fine g\u00f6re bunun sebebi, g\u00fcn\u00fcm\u00fczden 1000-2000 y\u0131l kadar \u00f6nce Bantuca konu\u015fan gruplar\u0131n yanlar\u0131nda tar\u0131mc\u0131l\u0131k ve kendi dillerini de ta\u015f\u0131yarak Bat\u0131 Afrika\u2019dan Do\u011fu ve G\u00fcney Afrika\u2019ya g\u00f6\u00e7 etmi\u015f olmalar\u0131. Bu g\u00f6\u00e7menlerin gittikleri yerdeki avc\u0131-toplay\u0131c\u0131lar\u0131n yerini ald\u0131klar\u0131 d\u00fc\u015f\u00fcn\u00fcl\u00fcyor. Tanzanya\u2019n\u0131n Zanzibar Yar\u0131madas\u0131\u2019nda g\u00fcn\u00fcm\u00fczden 750 y\u0131l \u00f6nce, yani s\u00f6z\u00fc edilen g\u00f6\u00e7 dalgas\u0131ndan sonra ya\u015fam\u0131\u015f bir bireyin G\u00fcney ve Do\u011fu Afrikal\u0131 avc\u0131-toplay\u0131c\u0131larla herhangi bir yak\u0131nl\u0131\u011f\u0131n\u0131n bulunmad\u0131\u011f\u0131 g\u00f6r\u00fcl\u00fcyor.<\/p>\n \u0130sve\u00e7\u2019teki Uppsala \u00dcniversitesi\u2019nden Mattias Jakobsson\u2019un ekibi ise 2000 y\u0131l \u00f6nce G\u00fcney Afrika\u2019daki Ballito K\u00f6rfezi\u2019nde ya\u015fam\u0131\u015f olan bir \u00e7ocuk ve 6 di\u011fer antik G\u00fcney Afrikal\u0131n\u0131n genomlar\u0131n\u0131 inceleyerek ayn\u0131 g\u00f6\u00e7 dalgas\u0131n\u0131n izlerine ula\u015ft\u0131. \u00c7al\u0131\u015fmalar\u0131 ge\u00e7ti\u011fimiz ay yay\u0131nlanmak \u00fczere bioRxiv\u2019e g\u00f6nderildi.<\/p>\n Schieffels, g\u00f6\u00e7 dalgas\u0131n\u0131n izlerine hem arkeolojik alanlarda g\u00f6zlemlenebilen Bantu\u2019lar\u0131n hareketlili\u011fi, hem de g\u00fcn\u00fcm\u00fczdeki Afrikal\u0131lar\u0131n DNA\u2019lar\u0131n\u0131n incelenmesi sonucu ula\u015f\u0131labildi\u011fini s\u00f6yl\u00fcyor. Bu g\u00f6\u00e7\u00fcn ger\u00e7ekli\u011fini do\u011frudan kan\u0131tlarla destekleyebilmek olduk\u00e7a sevindirici diye de ekliyor.<\/p>\n \u201cHayalet pop\u00fclasyon\u201d potansiyeli<\/strong><\/p>\n Antik Afrikal\u0131lar\u0131n genomlar\u0131 \u00e7ok daha \u00f6ncelerde ger\u00e7ekle\u015fen olaylar\u0131 ayd\u0131nlatma potansiyeli de ta\u015f\u0131yor. Jakobsson\u2019\u0131n ekibi, kal\u0131nt\u0131lar\u0131 Ballito K\u00f6rfezi\u2019nden \u00e7\u0131kar\u0131lan \u00e7ocu\u011fun genomuna dayanarak\u00a0Homo sapiens<\/em>\u2019in san\u0131lan\u0131n \u00e7ok daha \u00f6ncesinde, 260.000 y\u0131l \u00f6nce ortaya \u00e7\u0131kt\u0131\u011f\u0131n\u0131 iddia ediyor. Bu s\u0131rada Skoglund\u2019\u0131n ekibi bu antik genomlar\u0131 olas\u0131 bir \u201chayalet pop\u00fclasyon\u201d ortaya \u00e7\u0131karmak i\u00e7in kullan\u0131yor. Ekibin belirtti\u011fine g\u00f6re bu \u201chayalet pop\u00fclasyon\u201d di\u011fer b\u00fct\u00fcn Afrikal\u0131 gruplardan daha \u00f6nce\u00a0H. sapiens<\/em>\u2019in kurucu pop\u00fclasyonundan ayr\u0131ld\u0131 ve sonralar\u0131 g\u00fcn\u00fcm\u00fcz\u00fcn Bat\u0131 Afrikal\u0131lar\u0131n\u0131n genetik \u00f6zelliklerine katk\u0131da bulundu.<\/p>\n Philadelphia\u2019daki Pennsylvania \u00dcniversitesi\u2019nden bir pop\u00fclasyon genetik\u00e7isi olan Iain Mathieson, antik Afrikal\u0131lar\u0131n DNA\u2019lar\u0131n\u0131n bundan 50.000-100.000 y\u0131l \u00f6nce k\u0131tada ya\u015fayan yerlilerin \u201cgenetik resmini\u201d ortaya \u00e7\u0131kararak atalar\u0131m\u0131z\u0131n Afrika\u2019n\u0131n d\u0131\u015f\u0131na nas\u0131l g\u00f6\u00e7 ettiklerini a\u00e7\u0131klamam\u0131za yard\u0131mc\u0131 olmas\u0131n\u0131 umuyor.<\/p>\n Bu birka\u00e7 biny\u0131ldan \u00e7ok daha eski zamanlara ait DNA\u2019lar elde etmemizi ve bu DNA\u2019lar\u0131 elde etmemizi sa\u011flayacak b\u00fcy\u00fck teknolojik ilerlemeleri gerektirebilir. Bilinen en eski\u00a0H. sapiens<\/em>\u2019lere ait oldu\u011fu d\u00fc\u015f\u00fcn\u00fclen ve Morokko\u2019da bulunan 300.000 y\u0131ll\u0131k kemiklerden \u015fimdiye kadar analiz edilebilir DNA elde edilemedi. Mathieson konuyla ilgili \u015f\u00f6yle diyor: \u201cHen\u00fcz antik Afrikal\u0131lar\u0131n genomunu inceleme i\u015finin ba\u015f\u0131nday\u0131z, hem de \u00e7ok ba\u015f\u0131nda\u201d.<\/p>\n","protected":false},"excerpt":{"rendered":" Ara\u015ft\u0131rmac\u0131lar taraf\u0131ndan uzun zamand\u0131r g\u00f6z ard\u0131 edilen Afrika\u2019da biny\u0131llar \u00f6nce ya\u015fam\u0131\u015f insanlar\u0131n genomlar\u0131 sonunda incelenmeye ba\u015fland\u0131. 20 bireyin genomunun incelendi\u011fi iki ayr\u0131 projenin sonu\u00e7lar\u0131, ge\u00e7ti\u011fimiz hafta a\u00e7\u0131kland\u0131 ve t\u00fcr\u00fcm\u00fcz\u00fcn Afrika\u2019daki ge\u00e7mi\u015finin sand\u0131\u011f\u0131m\u0131zdan \u00e7ok daha karma\u015f\u0131k oldu\u011fu ortaya \u00e7\u0131kt\u0131. Afrika\u2019n\u0131n \u015fimdiye kadar antik-DNA ara\u015ft\u0131rmac\u0131lar\u0131 taraf\u0131ndan ihmal edilmesinin nedeniyse k\u0131tan\u0131n kavurucu iklimi. Y\u00fcksek s\u0131cakl\u0131klar DNA\u2019n\u0131n bozunmas\u0131n\u0131 h\u0131zland\u0131rd\u0131\u011f\u0131 […]<\/p>\n","protected":false},"author":428,"featured_media":12840,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1125,211,19,21],"tags":[523,272,431,773,230],"class_list":["post-12839","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-162-sayi","category-antropoloji","category-bilim-gundemi","category-biyoloji","tag-afrika","tag-dna","tag-gen","tag-genom","tag-insanlik-tarihi"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/12839","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\/428"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=12839"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/12839\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media\/12840"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=12839"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=12839"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=12839"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}