{"id":2502,"date":"2015-04-08T22:39:35","date_gmt":"2015-04-08T19:39:35","guid":{"rendered":"http:\/\/bilimvegelecek.com.tr\/?p=2502"},"modified":"2015-04-08T22:39:35","modified_gmt":"2015-04-08T19:39:35","slug":"ilk-insanlar-da-bizler-gibi-farkli-vucut-tiplerindeydi","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2015\/04\/08\/ilk-insanlar-da-bizler-gibi-farkli-vucut-tiplerindeydi","title":{"rendered":"\u0130lk insanlar da bizler gibi farkl\u0131 v\u00fccut tiplerindeydi…"},"content":{"rendered":"

G\u00f6rsel: Bir Homo erectus<\/em> canland\u0131rmas\u0131.<\/p>\n

Fosil par\u00e7alar\u0131ndan yararlanan yeni bir ara\u015ft\u0131rma, t\u00fcr\u00fcm\u00fcz\u00fcn 2 milyon y\u0131l \u00f6nce ortaya \u00e7\u0131k\u0131\u015f\u0131ndan beri farkl\u0131 boy, a\u011f\u0131rl\u0131k ve \u00f6l\u00e7\u00fclerde oldu\u011funu g\u00f6steriyor ve insano\u011flunun Avrasya\u2019ya hen\u00fcz modern insandan daha k\u0131sa ve hafifken yay\u0131lmaya ba\u015flad\u0131\u011f\u0131 g\u00f6r\u00fc\u015f\u00fcn\u00fc kuvvetlendiriyor.
\nEvrimimizle ilgili en yayg\u0131n teorilerden biri t\u00fcr\u00fcm\u00fcz Homo\u2019nun, v\u00fccut boyutu daha k\u00fc\u00e7\u00fck olan ilk insanlardan, Afrika\u2019n\u0131n \u00f6tesine g\u00f6\u00e7 edip Avrasya\u2019ya yay\u0131labilen daha uzun, daha a\u011f\u0131r ve daha uzun bacakl\u0131 Homo erectus\u2019a evrimle\u015fti\u011fi y\u00f6n\u00fcndeydi. Boy ortalamas\u0131 1,5 metrenin, a\u011f\u0131rl\u0131k ortalamas\u0131 50 kg\u2019\u0131n alt\u0131nda olan k\u00fc\u00e7\u00fck v\u00fccutlu Homo erectus\u2019un 1,77 milyon y\u0131l \u00f6nce g\u00fcney Avrupa\u2019da G\u00fcrcistan\u2019da ya\u015fad\u0131\u011f\u0131 biliniyor olsa da, modern insanla ili\u015fkilendirilen daha b\u00fcy\u00fck v\u00fccudun zamansal ve co\u011frafi k\u00f6keni \u015fimdiye kadar \u00e7\u00f6z\u00fclememi\u015fti.
\nFakat Cambridge \u00dcniversitesi ve T\u00fcbingen \u00dcniversitesi (Almanya) taraf\u0131ndan y\u00fcr\u00fct\u00fclen ve 26 Mart 2015\u2019te Journal of Human Evolution\u2019da yay\u0131mlanan bir ara\u015ft\u0131rma, v\u00fccut b\u00fcy\u00fckl\u00fc\u011f\u00fcndeki esas art\u0131\u015f\u0131n Homo erectus\u2019un Afrika\u2019dan ayr\u0131l\u0131\u015f\u0131ndan on binlerce y\u0131l sonra ve ilk olarak Kenya\u2019da Koobi Fora b\u00f6lgesinde ger\u00e7ekle\u015fti\u011fini g\u00f6sterdi. T\u00fcbingen \u00dcniversitesi, Erken Prehistorya ve Kuaterner Ekoloji B\u00f6l\u00fcm\u00fc\u2019nden ara\u015ft\u0131rmac\u0131 Manuel Will\u2019e g\u00f6re \u201cBu nedenle daha b\u00fcy\u00fck bedenler ve uzun bacaklar\u0131n evrimi, art\u0131k t\u00fcr\u00fcm\u00fcz\u00fcn Avrasya\u2019ya ilk yolculu\u011fundaki temel etken olarak g\u00f6r\u00fclemez.\u201d
\nAra\u015ft\u0131rmac\u0131lar, k\u00fc\u00e7\u00fck fosil par\u00e7alar\u0131n\u0131n ilk atalar\u0131m\u0131z\u0131n uzunlu\u011funu ve v\u00fccut a\u011f\u0131rl\u0131\u011f\u0131n\u0131 tespit etmek i\u00e7in kullan\u0131ld\u0131\u011f\u0131 yeni ara\u015ft\u0131rma y\u00f6nteminden elde ettikleri sonu\u00e7lar\u0131n, g\u00fcn\u00fcm\u00fczde v\u00fccut boyutlar\u0131nda g\u00f6zlenen \u00e7e\u015fitlili\u011fin san\u0131ld\u0131\u011f\u0131ndan \u00e7ok daha \u00f6nce ortaya \u00e7\u0131kt\u0131\u011f\u0131n\u0131 g\u00f6sterdi\u011fini belirtiyorlar.
\nAra\u015ft\u0131rman\u0131n yazarlar\u0131ndan, Cambridge \u00dcniversitesi Arkeoloji ve Antropoloji B\u00f6l\u00fcm\u00fc \u00dcyesi Dr. Jay Stock, \u201cG\u00f6zlemledi\u011fimiz \u015fey, belki de t\u00fcr\u00fcm\u00fcze \u00f6zg\u00fc bir \u00f6zelli\u011fin ba\u015flang\u0131c\u0131, \u00e7e\u015fitlili\u011fin k\u00f6keni\u201d diyor. \u201cBulgular\u0131, ilk insan\u0131n Homo habilis, Homo ergaster, Homo rudolfensis gibi birden fazla t\u00fcr\u00fc oldu\u011fu ya da kendi i\u00e7inde ola\u011fan\u00fcst\u00fc \u00e7e\u015fitlilik g\u00f6steren tek bir t\u00fcr oldu\u011fu \u015feklinde de yorumlamak m\u00fcmk\u00fcn. Bu durum, Homo cinsinin ilk \u00fcyeleri aras\u0131nda b\u00fcy\u00fck \u00e7e\u015fitlilik g\u00f6steren en son kafatas\u0131 bulgular\u0131yla da \u00f6rt\u00fc\u015f\u00fcyor. E\u011fer birisi size \u2018Modern insan 180 cm ve 70 kg m\u0131d\u0131r?\u2019 diye sorsa, \u2018Baz\u0131lar\u0131 \u00f6yle; ama pek \u00e7ok insan da \u00f6yle de\u011fil\u2019 diye cevap verirdiniz. Bizim g\u00f6stermeye ba\u015flad\u0131\u011f\u0131m\u0131z da, bu \u00e7e\u015fitlili\u011fin insan evriminin ilk a\u015famalar\u0131ndan itibaren ortaya \u00e7\u0131kt\u0131\u011f\u0131\u201d diye ekliyor.
\nGezegenimizi mamutlar ve k\u0131l\u0131\u00e7 di\u015fli kaplanlarla payla\u015fan, bundan 2,5 ila 1,5 milyon y\u0131l \u00f6nce ya\u015fam\u0131\u015f insanlar\u0131n v\u00fccut b\u00fcy\u00fckl\u00fcklerini konu alan bu ara\u015ft\u0131rm, son 20 y\u0131lda bir ilk. Bu \u00e7al\u0131\u015fmayla ayn\u0131 zamanda ilk defa, baz\u0131lar\u0131 ayak parmaklar\u0131 gibi k\u00fc\u00e7\u00fck, baz\u0131lar\u0131 boyu 5 cm\u2019i ge\u00e7meyen ince ayak bile\u011fi kemikleri gibi pek \u00e7ok fosil par\u00e7as\u0131, v\u00fccut b\u00fcy\u00fckl\u00fc\u011f\u00fcn\u00fc tespit etmede kullan\u0131ld\u0131.
\nKenya, Tanzanya, G\u00fcney Afrika ve G\u00fcrcistan\u2019da bulunan fosillerin \u00f6l\u00e7\u00fcmleri kar\u015f\u0131la\u015ft\u0131r\u0131ld\u0131\u011f\u0131nda, ara\u015ft\u0131rmac\u0131lar pleistosen d\u00f6nemi insanlar\u0131nda belirgin b\u00f6lgesel farkl\u0131l\u0131klar oldu\u011funu buldular. G\u00fcney Afrika ma\u011faralar\u0131nda ya\u015fayanlar ortalama 150 cm uzunlu\u011fundayken, Kenya\u2019n\u0131n Koobi Fora b\u00f6lgesinde ya\u015fayanlar\u0131n boyu, bug\u00fcnk\u00fc \u0130ngiliz yeti\u015fkin erkek n\u00fcfusunun boy ortalamas\u0131yla benzer bi\u00e7imde 180 cm\u2019yi buluyor.
\nStock, \u201c\u0130nsan evrimiyle ilgili her ders kitab\u0131, insan t\u00fcr\u00fcn\u00fcn bir soyunun daha b\u00fcy\u00fck bedenlere sahip olacak \u015fekilde evrildi\u011fi ve bu soydan gelenlerin Afrika\u2019n\u0131n \u00f6tesine yay\u0131ld\u0131\u011f\u0131 bak\u0131\u015f a\u00e7\u0131s\u0131n\u0131 i\u00e7eriyor. Fakat k\u00f6kenimize ve Afrika d\u0131\u015f\u0131na \u00e7\u0131k\u0131\u015f\u0131m\u0131za dair bu hik\u00e2yeyi yeni bulgular desteklemiyor\u201d diyor. \u201cKonuyla ilgili ilk ipu\u00e7lar\u0131, k\u00fc\u00e7\u00fck v\u00fccutlu insanlar\u0131n G\u00fcrcistan\u2019\u0131n Dmanisi b\u00f6lgesinde bulunan, 1,77 milyon y\u0131l \u00f6ncesine tarihlenmi\u015f fosilleri. Bu bir s\u00fcredir biliniyordu; ancak \u015fimdi biliyoruz ki b\u00fcy\u00fck boyutlu v\u00fccut belirgin bir bi\u00e7imde Do\u011fu Afrika\u2019da, Kenya\u2019n\u0131n Koobi Fora b\u00f6lgesinde, 1,7 milyon y\u0131l \u00f6nce evrimle\u015fti\u201d diye ekliyor.
\n \u201cYorumlar\u0131m\u0131z\u0131 basitle\u015ftirmeye \u00e7al\u0131\u015f\u0131yoruz; \u00e7\u00fcnk\u00fc fosil kal\u0131nt\u0131lar par\u00e7al\u0131 ve buluntular\u0131 bir \u015fekilde a\u00e7\u0131klamak zorunday\u0131z. Ancak var olan \u00e7e\u015fitlili\u011fi a\u00e7\u0131\u011fa \u00e7\u0131karmak, genel ve kapsaml\u0131 a\u00e7\u0131klamalar kadar \u00f6nemli\u201d diye de belirtiyor.
\nGe\u00e7mi\u015f ara\u015ft\u0131rmalar 10-15 fosillik k\u00fc\u00e7\u00fck \u00f6rnek gruplar\u0131n\u0131 temel almaktayd\u0131; \u00e7\u00fcnk\u00fc uzunluk ve v\u00fccut a\u011f\u0131rl\u0131\u011f\u0131n\u0131 hesaplama teknikleri, kal\u00e7a eklemi ya da bacak kemi\u011finin b\u00fcy\u00fck bir b\u00f6l\u00fcm\u00fc gibi spesifik kemik par\u00e7alar\u0131n\u0131 gerektiriyordu. Stock ve Will \u00fc\u00e7 kat fazla \u00f6rnekle, Afrika ve G\u00fcrcistan\u2019\u0131n her yerinden, 40\u2019tan fazla numunenin v\u00fccut b\u00fcy\u00fckl\u00fc\u011f\u00fcn\u00fc de\u011ferlendirerek \u015fimdiye kadar ger\u00e7ekle\u015ftirilmi\u015f en geni\u015f kar\u015f\u0131la\u015ft\u0131rmal\u0131 ara\u015ft\u0131rmaya imza att\u0131lar.
\nStock ve Will, yeni fosillerin ke\u015ffedilmesini ve bu fosillerin belirtilen spesifik kemikleri i\u00e7ermesini ummak yerine, farkl\u0131 bir yakla\u015f\u0131mla daha \u00f6nce incelenmi\u015f fosillerden faydalanmaya karar verdi. Stock\u2019\u0131n \u201cfazlas\u0131yla zorlu bir proje\u201d olarak de\u011ferlendirdi\u011fi, ayak parma\u011f\u0131 kadar k\u00fc\u00e7\u00fck kemiklerden v\u00fccut a\u011f\u0131rl\u0131\u011f\u0131 ve boyu hesaplamaya yarayan denklemleri elde etme \u00e7abalar\u0131 bir senelerini ald\u0131. Ara\u015ft\u0131rmac\u0131lar bu kemikleri, d\u00fcnyan\u0131n d\u00f6rt bir yan\u0131ndan 800\u2019den fazla modern avc\u0131-toplay\u0131c\u0131 bireye ait iskeletlerin \u00f6l\u00e7\u00fcmleriyle kar\u015f\u0131la\u015ft\u0131rarak ve \u00e7e\u015fitli regresyon denklemlerini kullanarak, daha \u00f6nce bu y\u00f6ntemle hi\u00e7 \u00e7al\u0131\u015f\u0131lmam\u0131\u015f olan fosil buluntulardan yola \u00e7\u0131karak ait olduklar\u0131 bireylerin v\u00fccut b\u00fcy\u00fckl\u00fcklerini tespit ettiler.
\n\u201c\u0130nsan evriminde v\u00fccut b\u00fcy\u00fckl\u00fc\u011f\u00fc en \u00f6nemli \u00f6zelliklerden biri olarak g\u00f6r\u00fcl\u00fcr. \u2018Daha b\u00f6l\u00fck p\u00f6r\u00e7\u00fck\u2019 bu fosillerin incelemesiyle de insan v\u00fccut boyutlar\u0131ndaki farkl\u0131l\u0131klar\u0131n ne zaman ortaya \u00e7\u0131kt\u0131\u011f\u0131yla ilgili \u00e7ok daha fazla bilgi edinebiliyoruz. 1,7 milyon y\u0131l \u00f6nce atalar\u0131m\u0131z\u0131n pek az\u0131 150 cm\u2019den uzun ya da kiloca a\u011f\u0131rd\u0131\u201d diyorlar.
\nStock, \u201cV\u00fccut \u00f6l\u00e7\u00fclerinin daha uzun ve daha a\u011f\u0131r bireylere do\u011fru kaymaya ba\u015flamas\u0131 ilk olarak belirli bir yerde, Kenya\u2019n\u0131n kuzeyindeki Koobi Fora b\u00f6lgesinde, 1,7 milyon y\u0131l \u00f6nce ba\u015flad\u0131. Art\u0131k v\u00fccut b\u00fcy\u00fckl\u00fc\u011f\u00fcn\u00fc t\u00fcrlerin de\u011fi\u015fmez ve temel bir \u00f6zelli\u011fi olarak g\u00f6rmek yerine, hangi b\u00f6lgesel ko\u015fullar\u0131n v\u00fccut boyutlar\u0131ndaki \u00e7e\u015fitlili\u011fi ortaya \u00e7\u0131kard\u0131\u011f\u0131na odaklanabiliriz\u201d diye ekliyor.<\/p>\n

\u00c7eviren: \u0130dil Yaranl\u0131
\nBilkent \u00dcnv. Bilgisayar M\u00fchendisli\u011fi<\/strong><\/em><\/p>\n

Kaynak:<\/strong> http:\/\/www.sciencedaily.com\/releases\/2015\/03\/150326204642.htm<\/p>\n","protected":false},"excerpt":{"rendered":"

G\u00f6rsel: Bir Homo erectus canland\u0131rmas\u0131. Fosil par\u00e7alar\u0131ndan yararlanan yeni bir ara\u015ft\u0131rma, t\u00fcr\u00fcm\u00fcz\u00fcn 2 milyon y\u0131l \u00f6nce ortaya \u00e7\u0131k\u0131\u015f\u0131ndan beri farkl\u0131 boy, a\u011f\u0131rl\u0131k ve \u00f6l\u00e7\u00fclerde oldu\u011funu g\u00f6steriyor ve insano\u011flunun Avrasya\u2019ya hen\u00fcz modern insandan daha k\u0131sa ve hafifken yay\u0131lmaya ba\u015flad\u0131\u011f\u0131 g\u00f6r\u00fc\u015f\u00fcn\u00fc kuvvetlendiriyor. Evrimimizle ilgili en yayg\u0131n teorilerden biri t\u00fcr\u00fcm\u00fcz Homo\u2019nun, v\u00fccut boyutu daha k\u00fc\u00e7\u00fck olan ilk insanlardan, […]<\/p>\n","protected":false},"author":1,"featured_media":2503,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[211,19,32],"tags":[],"class_list":["post-2502","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-antropoloji","category-bilim-gundemi","category-evrim"],"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