{"id":23456,"date":"2015-03-01T15:11:47","date_gmt":"2015-03-01T13:11:47","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=23456"},"modified":"2018-04-17T15:17:04","modified_gmt":"2018-04-17T12:17:04","slug":"neandertaller-ile-atalarimiz-55-binyil-once-melezlesti","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2015\/03\/01\/neandertaller-ile-atalarimiz-55-binyil-once-melezlesti","title":{"rendered":"Neandertaller ile atalar\u0131m\u0131z 55 biny\u0131l \u00f6nce melezle\u015fti!"},"content":{"rendered":"

Paleogenetik \u00e7al\u0131\u015fmalar hepimizin, \u00f6zellikle de Avrasyal\u0131lar\u0131n k\u00fc\u00e7\u00fck de olsa bir miktar Neandertal geni ta\u015f\u0131d\u0131\u011f\u0131n\u0131 kan\u0131tlam\u0131\u015ft\u0131. Ancak Neandertaller ile modern insan aras\u0131nda ger\u00e7ekle\u015fen melezle\u015fme genetik \u00e7al\u0131\u015fmalarla ortaya konmu\u015f g\u00f6r\u00fcnse de, morfolojik ya da k\u00fclt\u00fcrel bir kan\u0131ta ula\u015f\u0131lamam\u0131\u015ft\u0131. 2015 y\u0131l\u0131 \u00f6nemli haberlerlerle ba\u015flad\u0131: \u0130srail\u2019de Manot Ma\u011faras\u0131\u2019nda bulunan ve 55 biny\u0131l \u00f6nceye tarihlendirilen kafatas\u0131 fosili, Neandertal ile modern insan aras\u0131 \u00f6zellikler ta\u015f\u0131yor.<\/em><\/p>\n

\"\"
\u015eekil 1: Neandertal-modern insan melezi oldu\u011fu d\u00fc\u015f\u00fcn\u00fclen fosilin bulundu\u011fu Manot Ma\u011faras\u0131\u2019n\u0131n co\u011frafik lokasyonu (Hershkovitz ve di\u011f. 2015).<\/figcaption><\/figure>\n

Kendi t\u00fcr\u00fcm\u00fcz olan Homo sapiens<\/em>\u2019in evrimsel tarihini \u00f6\u011frenmenin ve anlaman\u0131n en \u00f6nemli yollar\u0131ndan biri de, kendi genetik bilgimizi en yak\u0131n akrabalar\u0131m\u0131z olan insans\u0131 maymunlar (\u015fempanze, goril ve orangutan) ile kar\u015f\u0131la\u015ft\u0131rmakt\u0131r. Bununla birlikte atalar\u0131m\u0131z, evrimsel olarak insans\u0131 maymunlardan b\u00fcy\u00fck olas\u0131l\u0131kla 6 milyon y\u0131l \u00f6nce ayr\u0131\u015ft\u0131. Bu nedenle insans\u0131 maymunlar g\u00f6rece uzak akrabalar\u0131m\u0131z say\u0131l\u0131r. Kendi evrimsel tarihimizin jeolojik zamanlar i\u00e7erisinde sakl\u0131 olan bilinmeyenlerini ayd\u0131nlatman\u0131n en kesin yolu ise, kendi morfolojik ve anatomik \u00f6zelliklerimizi bizlere evrimsel olarak daha yak\u0131n olan atalar\u0131m\u0131z\u0131nki ile kar\u015f\u0131la\u015ft\u0131rmak, hatta bu fosil atalar\u0131m\u0131z\u0131n kal\u0131nt\u0131lar\u0131ndan atasal DNA elde etmek m\u00fcmk\u00fcn ise genetik bilgimizi de kar\u015f\u0131la\u015ft\u0131rmakt\u0131r. DNA materyali kemik i\u00e7erisinde \u00e7ok uzun d\u00f6nemler korunabilse de -donma gibi \u00f6zel ko\u015fullar haricinde- DNA\u2019s\u0131 korunmu\u015f en eski insan atas\u0131 fosili yakla\u015f\u0131k olarak 400 bin ya\u015f\u0131nda.<\/p>\n

Neandertal genomu tamamen \u00e7\u00f6z\u00fclm\u00fc\u015f durumda<\/strong><\/p>\n

Bu tarihten g\u00fcn\u00fcm\u00fcze \u00f6zellikle Neandertal<\/em> fosillerinden elde edilen genetik bilgi -kald\u0131 ki Neandertal<\/em>lerin b\u00fct\u00fcn genom dizilimini \u00f6\u011frenmi\u015f durumday\u0131z- bizlere atalar\u0131m\u0131z ile olan evrimsel ili\u015fkilerimiz ve bizden farkl\u0131 olarak ka\u00e7 farkl\u0131 insan t\u00fcr\u00fcn\u00fcn bug\u00fcne kadar ya\u015fad\u0131\u011f\u0131 hakk\u0131nda \u00f6nemli bilgiler veriyor.<\/p>\n

\u0130lk Neandertal<\/em> DNA\u2019s\u0131 1997 y\u0131l\u0131nda Svente P\u00e4\u00e4bo ve ekibi taraf\u0131ndan elde edilmi\u015fti. Ard\u0131ndan 2000 y\u0131l\u0131nda Mezmaiskaya (Rusya); Vindija (H\u0131rvatistan); 2004\u2019de Engis (Bel\u00e7ika); Le Chapelle-aux-Saints ve La Rochers-de-Villeneuve (Fransa); 2005, 2006 ve 2011 y\u0131llar\u0131nda El Sidron (\u0130spanya); 2006 y\u0131l\u0131nda Monti Lessini (\u0130talya) ve Scladina (Bel\u00e7ika); 2007 y\u0131l\u0131nda Te\u015fik Ta\u015f (\u00d6zbekistan) ve Okladnivok (Rusya) ve 2012 y\u0131l\u0131nda Valdegoba (\u0130spanya) lokalitelerinden bulunan Neandertal<\/em> fosillerinden elde edilen DNA bilgisi, b\u00fct\u00fcn Neandertal<\/em> genomuna sahip olmam\u0131z\u0131 sa\u011flad\u0131.<\/p>\n

Genel olarak, elde edilen Neandertal<\/em> genetik bilgisinden \u00f6\u011frendi\u011fimiz en \u00f6nemli veri, onlar\u0131n \u00e7ok d\u00fc\u015f\u00fck genetik \u00e7e\u015fitlili\u011fe sahip oldu\u011fuydu. Ayr\u0131ca genetik bilginin yan\u0131nda, arkeolojik ve antropolojik kan\u0131tlar da onlar\u0131n k\u00fc\u00e7\u00fck gruplar halinde ya\u015fad\u0131\u011f\u0131n\u0131 g\u00f6steriyordu. Neandertal<\/em>ler hakk\u0131nda \u00f6\u011frendi\u011fimiz di\u011fer \u00f6nemli bir bilgi ise, onlar\u0131n bizler gibi kompleks seslerden olu\u015fan bir konu\u015fma diline sahip olmad\u0131klar\u0131yd\u0131. Ara\u015ft\u0131rmac\u0131lar Neandertal<\/em>lerden elde edilen genetik bilgi ile bizimkini kar\u015f\u0131lat\u0131rarak konu\u015fma yetene\u011fimizi d\u00fczenleyen FOXP2 genlerinde farkl\u0131l\u0131klar oldu\u011funu g\u00f6zlemledi.<\/p>\n

Neandertal ve Denisova insan\u0131n\u0131n genlerini ta\u015f\u0131yoruz!<\/strong><\/p>\n

2010 y\u0131l\u0131nda, Neandertal<\/em>lerin b\u00fct\u00fcn genom dizilimini \u00f6\u011frenmemizin yan\u0131 s\u0131ra, ayr\u0131ca Altay Da\u011flar\u0131\u2019nda bulunan Denisova Ma\u011faras\u0131\u2019nda ke\u015ffedilen ve Denisova insan\u0131 olarak adland\u0131r\u0131lan farkl\u0131 bir insan t\u00fcr\u00fcn\u00fcn de Neandertal<\/em> ve modern insan ile birlikte ayn\u0131 d\u00f6nemlerde ve yak\u0131n co\u011frafyalarda ya\u015fad\u0131\u011f\u0131n\u0131 \u00f6\u011frendik. Denisova insan\u0131n\u0131n parmak kemi\u011finden elde edilen genetik bilgi, bu insan\u0131n\u0131n atas\u0131n\u0131n Neandertal<\/em> ve modern insan\u0131n ortak atas\u0131ndan yakla\u015f\u0131k bir milyon y\u0131l \u00f6nce ayr\u0131\u015ft\u0131\u011f\u0131n\u0131 g\u00f6steriyor.<\/p>\n

Genel olarak bizlerin, yani anatomik olarak modern insan\u0131n genetik bilgisi Neandertal<\/em>\u2019inki ile kar\u015f\u0131la\u015ft\u0131r\u0131l\u0131nca, Afrikal\u0131 olmayan modern insanlar\u0131n Sahra-alt\u0131 Afrikal\u0131lara g\u00f6re Neandertal<\/em>ler ile y\u00fczde 1-4 aras\u0131nda daha fazla genetik benzerlik payla\u015ft\u0131\u011f\u0131 ortaya \u00e7\u0131kt\u0131. Bununla birlikte, g\u00fcn\u00fcm\u00fcz Melanezyal\u0131lar\u0131n genetik yap\u0131lar\u0131n\u0131n d\u00fcnyan\u0131n di\u011fer k\u0131sm\u0131nda ya\u015fayanlar\u0131na g\u00f6re Denisova insan\u0131 ile y\u00fczde 4-6 oranlar\u0131nda daha fazla benzerlik payla\u015ft\u0131\u011f\u0131 da g\u00f6r\u00fcld\u00fc. Bu bulgular, Neandertal<\/em>lerin Sahra-alt\u0131 Afrikal\u0131lar\u0131n atalar\u0131 d\u0131\u015f\u0131nda, \u00f6zellikle Avrasyal\u0131 modern insanlar ile genetik olarak melezle\u015fti\u011fini, hatta Denisova insan\u0131 ile daha fazla benzerlikler payla\u015fan G\u00fcneydo\u011fu Asyal\u0131lar\u0131n atalar\u0131 ile daha fazla genetik melezle\u015fmenin ger\u00e7ekle\u015fti\u011fini de g\u00f6stermi\u015f oldu.<\/p>\n

Yaz\u0131n\u0131n buraya kadar okudu\u011funuz k\u0131sm\u0131nda, paleogenetik \u00e7al\u0131\u015fmalar\u0131n bizlere hepimizin, \u00f6zellikle de Avrasyal\u0131lar\u0131n k\u00fc\u00e7\u00fck de olsa bir miktar Neandertal<\/em> geni ta\u015f\u0131d\u0131\u011f\u0131m\u0131z\u0131 kan\u0131tlad\u0131\u011f\u0131na \u015fahit oldunuz.(1) <\/sup>Ancak Neandertal<\/em>ler ve modern insan aras\u0131nda ger\u00e7ekle\u015fen melezle\u015fme genetik \u00e7al\u0131\u015fmalarla kan\u0131tlanm\u0131\u015f g\u00f6r\u00fcnse de, morfolojik olarak bu melezle\u015fmenin ger\u00e7ekle\u015fti\u011fini g\u00f6steren g\u00fc\u00e7l\u00fc bir fosil ya da k\u00fclt\u00fcrel kan\u0131t hen\u00fcz bulunamam\u0131\u015ft\u0131. Bu anlamda 2015 y\u0131l\u0131 \u00f6nemli Neandertal<\/em> haberlerleri ile ba\u015flad\u0131.<\/p>\n

\"\"
\u015eekil 2: Manot Ma\u011faras\u0131\u2019nda ke\u015ffedilen kafatas\u0131n\u0131n (a) \u00fcstten, (b) yandan, (c) \u00f6nden ve (d) arkadan g\u00f6r\u00fcn\u00fcmleri.<\/figcaption><\/figure>\n

Neandertal-insan melezle\u015fmesine ilk morfolojik kan\u0131t<\/strong><\/p>\n

Bu haberlerden ilki Neandertal<\/em> ve modern insan melezle\u015fmesinin morfolojik kan\u0131tlar\u0131n\u0131 sunuyor. Ara\u015ft\u0131rmac\u0131lar \u0130srail\u2019de Manot Ma\u011faras\u0131\u2019nda (\u015eekil 1) uranyum-toryum tarihlendirmesine g\u00f6re 55 biny\u0131l \u00f6ncesine tarihlendirilen seviyede bir kafatas\u0131 par\u00e7as\u0131 (kafadam\u0131) ke\u015ffetti. Kafatas\u0131n\u0131n (\u015eekil 2) morfolojik \u00f6zellikleri -\u00f6zellikle de oksipital olarak adland\u0131ran art kafa kemi\u011fi morfolojisi- 50 biny\u0131l \u00f6nce Avrupa\u2019da bulunmu\u015f modern insanlar\u0131nkine benziyor. Bu tarihler, 60 bin ile 40 biny\u0131l \u00f6ncesi aras\u0131 anatomik olarak modern insan\u0131n Afrika\u2019dan Avrasya\u2019ya g\u00f6\u00e7 etti\u011fi zaman aral\u0131\u011f\u0131. 55 biny\u0131l \u00f6ncesine tarihlendirilen ve Neandertal<\/em> ve modern insan aras\u0131 \u00f6zellikler ta\u015f\u0131yan bu fosil bize, atalar\u0131m\u0131z\u0131n daha so\u011fuk ve \u00e7etin iklim ko\u015fullar\u0131n\u0131n egemen oldu\u011fu kuzeydeki topraklara, yani Avrupa ve Asya\u2019n\u0131n kuzeyine g\u00f6\u00e7 etmeden \u00f6nce, Neandertal<\/em>ler ile Levant b\u00f6lgesinde ka\u015f\u0131la\u015ft\u0131\u011f\u0131n\u0131 ve melezle\u015fti\u011fini g\u00f6steriyor. B\u00f6ylece ilk kez Afrika\u2019dan Levant\u2019a g\u00f6\u00e7 eden atalar\u0131m\u0131z burda Neandertal<\/em>ler ile melezle\u015ferek gerekli genetik ve mikrobiyolojik (faydal\u0131 bakteriler) donan\u0131m\u0131 edinerek evrimsel anlamda daha g\u00fc\u00e7l\u00fc ve dayan\u0131kl\u0131 bireyler olarak kuzeye g\u00f6\u00e7 ettiler.<\/p>\n

Tel Aviv \u00dcniversitesi\u2019nden ve makalenin ilk yazar\u0131 olan ara\u015ft\u0131rmac\u0131 Israel Hershkovitz \u201cKafatas\u0131n\u0131n y\u00fcz ve \u00e7ene b\u00f6lgesi olmamas\u0131 b\u00fcy\u00fck \u015fanss\u0131zl\u0131k, ancak sadece kafadam\u0131n\u0131n bulunmas\u0131 bile b\u00fcy\u00fck bir ke\u015fif olmas\u0131na yetiyor. Anatomik olarak modern, \u00f6zellikle Avrupal\u0131 Cro-Magnon insan\u0131na benziyor, ancak yine de baz\u0131 ilkin Afrikal\u0131 morfolojik \u00f6zelliklerini de koruyor. Muhte\u015fem! Bu bug\u00fcne kadar bulunmu\u015f Afrika ve Avrupa aras\u0131ndaki evrimsel ba\u011flant\u0131y\u0131 kuran ilk ke\u015fif\u201d \u015feklindeki yorumlar\u0131 ile ke\u015fif hakk\u0131ndaki d\u00fc\u015f\u00fcncelerini belirtiyor. Ayr\u0131ca 60 biny\u0131l \u00f6nce Afrika\u2019dan Avrasya\u2019ya g\u00f6\u00e7e ba\u015flayan atalar\u0131m\u0131z\u0131n 55 biny\u0131l \u00f6nce Manot Ma\u011faras\u0131\u2019nda Neandertaller ile kar\u015f\u0131la\u015ft\u0131\u011f\u0131 ve melezle\u015fti\u011fine dair tek kan\u0131t aday\u0131n\u0131n bu fosil oldu\u011funu ileri s\u00fcr\u00fcyor. Morfolojik olarak do\u011fru, ancak DNA bilgilerinin elde edilmesi bu sav\u0131 do\u011frulayabilir. Afrika-merkezli modern insan\u0131n k\u00f6keni sav\u0131n\u0131n babas\u0131 \u00fcnl\u00fc paleoantropolog Chris Strinder da, Hershkovitz\u2019e kat\u0131larak bu ke\u015ffin \u00f6nemli bir aday olabilece\u011fini belirtiyor.<\/p>\n

Neandertaller hem et\u00e7il, hem de ot\u00e7ul muydu?<\/strong><\/p>\n

Neandertal<\/em> akrabalar\u0131m\u0131z hakk\u0131nda yay\u0131mlanan di\u011fer bir \u00e7al\u0131\u015fma ise, onlar\u0131n ya\u015fad\u0131\u011f\u0131 ekoloji ve beslenmeleriyle ilgili. Bug\u00fcne kadar Neandertal<\/em>lerin diyetlerinde hayvansal besinlerin, yani etin egemen yiyecek oldu\u011funu d\u00fc\u015f\u00fcn\u00fcrd\u00fck. Ancak Amerikan Fiziksel Antropoloji dergisinde (American Journal of Physical Anthropology<\/em>) Fiorenza ve di\u011ferleri taraf\u0131ndan yay\u0131mlanan \u00e7al\u0131\u015fmada, Neandertal<\/em>lerin bilinenin aksine diyetlerine \u00f6nemli \u00f6l\u00e7\u00fcde bitkisel besinler de katm\u0131\u015f olmalar\u0131 gerekti\u011fi vurgulan\u0131yor. Bunun nedeni ise hayvansal besinlerden elde edece\u011fimiz hayvansal proteinin fiziksel bir limiti olmas\u0131; a\u015f\u0131r\u0131 miktarda al\u0131nan hayvansal protein \u00f6zellikle hamile kad\u0131nlar ve yeni do\u011fan bebekler de tehlikeli olabiliyor. Bu tehlikeden dolay\u0131 yani et-merkezli protein zehirlenmesini \u00f6nlemek i\u00e7in Neandertal<\/em>ler diyetlerine alternatif besin kaynaklar\u0131 katm\u0131\u015f olmal\u0131yd\u0131lar ki, bu da muhtemelen \u00e7e\u015fitli bitkisel besinler olmal\u0131yd\u0131. Bununla birlikte yine bu y\u0131l\u0131n ba\u015flar\u0131nda yay\u0131nlanan Geof Smith imzal\u0131 makale ise, zooarkelojik kan\u0131tlara g\u00f6re Neandertal<\/em>lerin \u00f6zellikle megafauna olarak bildi\u011fimiz mamut, fil ve gergedan gibi memeli t\u00fcrlerinden olu\u015fan hayvanlar\u0131 avlayarak beslendi\u011fini ileri s\u00fcr\u00fcyor.<\/p>\n

 <\/p>\n

Dipnot<\/strong><\/p>\n

1) Daha fazla bilgi i\u00e7in bkz. \u201cHepimiz Biraz Neandertaliz\u201d, Ferhat Kaya, Bilim ve Gelecek<\/em>, Say\u0131 121, ss.70-73.<\/p>\n

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

1) Hershkovitz ve di\u011f., (2015), \u201cLevantine cranium from Manot Cave (Israel) foreshadows the first European modern humans\u201d, Nature<\/em>, 28 Ocak 2015. doi:10.1038\/nature14134<\/p>\n

2) Fiorenza ve di\u011f., (2015), \u201cTo meat or not to meat? New Perspective on Nenaderthal Ecology\u201d, AJPA, Yearbook of Physical Anthropology<\/em>, 156, 43\u201371.<\/p>\n

3) Smith, G., (2015), \u201cNeanderthal megafaunalexploitaition in Western Europe and its dietary implications: A contextual reassessment of La Cotte de St Brelade (Jersey)\u201d, Journal of Human Evolution<\/em>, 78, 181-201.<\/p>\n","protected":false},"excerpt":{"rendered":"

Paleogenetik \u00e7al\u0131\u015fmalar hepimizin, \u00f6zellikle de Avrasyal\u0131lar\u0131n k\u00fc\u00e7\u00fck de olsa bir miktar Neandertal geni ta\u015f\u0131d\u0131\u011f\u0131n\u0131 kan\u0131tlam\u0131\u015ft\u0131. Ancak Neandertaller ile modern insan aras\u0131nda ger\u00e7ekle\u015fen melezle\u015fme genetik \u00e7al\u0131\u015fmalarla ortaya konmu\u015f g\u00f6r\u00fcnse de, morfolojik ya da k\u00fclt\u00fcrel bir kan\u0131ta ula\u015f\u0131lamam\u0131\u015ft\u0131. 2015 y\u0131l\u0131 \u00f6nemli haberlerlerle ba\u015flad\u0131: \u0130srail\u2019de Manot Ma\u011faras\u0131\u2019nda bulunan ve 55 biny\u0131l \u00f6nceye tarihlendirilen kafatas\u0131 fosili, Neandertal ile modern […]<\/p>\n","protected":false},"author":180,"featured_media":23459,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[170,211,32],"tags":[497,1049,230,529],"class_list":["post-23456","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-133-sayi","category-antropoloji","category-evrim","tag-homo-sapiens","tag-insanin-evrimi","tag-insanlik-tarihi","tag-neandertal"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/23456","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\/180"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=23456"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/23456\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media\/23459"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=23456"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=23456"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=23456"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}