Son y\u0131llarda Afrika\u2019n\u0131n \u00f6zellikle kuzeydo\u011fusunda ve do\u011fusunda \u00c7ad ile Kenya s\u0131n\u0131rlar\u0131 i\u00e7inde g\u00fcn \u0131\u015f\u0131\u011f\u0131na \u00e7\u0131kar\u0131lan hominid buluntular\u0131 insan ailesinin evrimindeki kay\u0131p halkalar konusunda bilim adamlar\u0131n\u0131 yeni bir tart\u0131\u015fma ortam\u0131na \u00e7ekti. 2000\u2019li y\u0131llardan itibaren atalar\u0131m\u0131z\u0131n evrim galerisine yeni hominid\u2019ler eklendi. \u0130nsan cinsi \u00f6ncesindeki ailemizin temsilcisinin sadece Australopitekus olmad\u0131\u011f\u0131n\u0131 bu \u00f6nemli ke\u015fiflerle anl\u0131yoruz. Ardipitekus, Sahelanthropus ve Orrorin bundan b\u00f6yle \u015fempanzelerle ortak yazg\u0131m\u0131z\u0131n ard\u0131ndan ba\u011f\u0131ms\u0131z bir kol olarak ayr\u0131 bir evrim hatt\u0131 olu\u015fturan hominid ailesinin Australopitekus \u00f6ncesi ilk duraklar\u0131yd\u0131. Ge\u00e7 miyosen \u00e7a\u011f ola\u011fan\u00fcst\u00fc Hominid \u00e7e\u015fitlili\u011fine tan\u0131k oldu.<\/p>\n
Ardipitekus ramidus ve kadabba adl\u0131 yeni t\u00fcrler erken pliyosen d\u00f6nemin Hominid\u2019leridir. Etiyopya\u2019da Hadar b\u00f6lgesinde 1994 y\u0131l\u0131nda bulunan ve 4,4 milyon y\u0131l \u00f6nce ya\u015fam\u0131\u015f oldu\u011fu belirlenen Ramidus t\u00fcr\u00fc \u00f6nce Australopitekus cinsi i\u00e7inde \u00f6ng\u00f6r\u00fcld\u00fc. Daha sonra bu cinsten d\u0131\u015flan\u0131p ayr\u0131 bir cins olarak tan\u0131mland\u0131. \u015eimdi t\u00fcm bilim d\u00fcnyas\u0131 bu t\u00fcr\u00fc Ardipitekus ramidus olarak bilmektedir. Son y\u0131llarda Ardipitekus cinsine yeni bir t\u00fcr daha kat\u0131ld\u0131. Bilim d\u00fcnyas\u0131 onu kadabba olarak tan\u0131maktad\u0131r. Bu yeni Hominid\u2019in beyni bir \u015fempanzeninkinden fazla iri de\u011fildir. Ancak, k\u00f6pekdi\u015fleri k\u00fc\u00e7\u00fclm\u00fc\u015ft\u00fcr. Molerlerinde mine incedir. Anatomisi Australopitekus\u2019unkinden ziyade \u015fempanzeninkini hat\u0131rlat\u0131r. \u015eempanze boyunda, 35-45 kg a\u011f\u0131rl\u0131\u011f\u0131nda bir Hominid oldu\u011fu anla\u015f\u0131lmaktad\u0131r. Di\u015flerinin yap\u0131s\u0131na bak\u0131l\u0131rsa, t\u0131pk\u0131 \u015fempanzeler gibi meyve a\u011f\u0131rl\u0131kl\u0131 besleniyormu\u015f. Di\u015fi ve erkek bedensel farkl\u0131l\u0131\u011f\u0131 ya da dik y\u00fcr\u00fcy\u00fcp y\u00fcr\u00fcmedikleri hakk\u0131nda bir \u015fey s\u00f6ylenemiyor.<\/p>\n
Orrorin tugenensis\u2019e gelince ortak ataya yak\u0131n bir ba\u015fka hominid t\u00fcr\u00fcyd\u00fc. 2000 y\u0131l\u0131nda Kenya\u2019da Tugen tepelerinde bulundu. Tugen, orijinal insan anlam\u0131na gelmektedir. Toplam alt\u0131 bireye ait fosil kal\u0131nt\u0131lar 6 milyon y\u0131l \u00f6ncesiyle ya\u015fland\u0131r\u0131ld\u0131. O halde bir ge\u00e7 miyosen d\u00f6nemi Hominid\u2019iydi. Olduk\u00e7a iyi korunmu\u015f bir kafatas\u0131 ve uzun kemiklerle temsil edilir. Femurun \u00fcst k\u0131sm\u0131, Orrorin tugenensis t\u00fcr\u00fcn\u00fcn iki ayak \u00fczerinde dola\u015ft\u0131\u011f\u0131n\u0131 g\u00f6stermektedir. \u0130ri bedenine oranla k\u00fc\u00e7\u00fck molerleri vard\u0131, k\u00f6pekdi\u015fleri k\u00fc\u00e7\u00fclm\u00fc\u015ft\u00fc. Ailemizin ba\u015flang\u0131c\u0131ndaki kay\u0131p halkan\u0131n nas\u0131l bir tiple temsil edildi\u011finin yan\u0131 s\u0131ra \u015fempanze- Hominid benzeri formlar\u0131n evrim s\u00fcre\u00e7lerinin nas\u0131l bir \u00e7er\u00e7eve i\u00e7inde olabilece\u011fine de \u0131\u015f\u0131k tutmaktad\u0131r.<\/p>\n
Sahelanthropus \u00e7adensis 2002 y\u0131l\u0131nda \u00c7ad\u2019da bir g\u00f6l k\u0131y\u0131s\u0131ndaki tortul tabakalar i\u00e7inde g\u00fcn \u0131\u015f\u0131\u011f\u0131na \u00e7\u0131kar\u0131ld\u0131. Yap\u0131lan analizler sonucu Sahelanthropus \u00e7adensis\u2019in a\u015fa\u011f\u0131 yukar\u0131 7 milyon y\u0131l eskiye ait oldu\u011fu anla\u015f\u0131ld\u0131. Bu nedenle ara\u015ft\u0131r\u0131c\u0131lar insan ailesinin bilinen bu en eski temsilcisini insanl\u0131\u011f\u0131n duayeni olarak adland\u0131rmaktad\u0131r. Hominid\u2019lerin Afrika\u2019daki varl\u0131\u011f\u0131n\u0131 bilinenden \u00e7ok daha eskiye \u00e7eken \u00f6nemli bir buluntudur. Tumai Hominid\u2019i olarak da bilinir. Bu sayede ailemizin ge\u00e7 miyosendeki temsilcilerinin kuzeydo\u011fu Afrika\u2019da da ya\u015fad\u0131\u011f\u0131n\u0131 \u00f6\u011freniyoruz. 320-380 cm3’l\u00fck bir beyin irili\u011fine sahipti. Son derece iyi korunmu\u015f kafatas\u0131nda y\u00fcz k\u0131sm\u0131 Hominid yap\u0131da, beyin kutusu ise \u00fcstten ve arkadan bir gorilinkini hat\u0131rlat\u0131r. Kafatas\u0131n\u0131n di\u015fiye mi yoksa erke\u011fe mi ait oldu\u011fu belirlenemedi. Ka\u015f kemerleri olduk\u00e7a belirgin, y\u00fcz \u00e7\u0131k\u0131nt\u0131s\u0131 fazla de\u011fildir. K\u00f6pekdi\u015fleri k\u00fc\u00e7\u00fclm\u00fc\u015f ve tepe k\u0131s\u0131mlar\u0131 a\u015f\u0131nm\u0131\u015ft\u0131r. Bu \u00f6zellik Hominid\u2019lerde g\u00f6r\u00fcl\u00fcr. K\u00f6pekdi\u015finin \u00f6n\u00fcnde diastema adl\u0131 bo\u015fluk yoktur. Molerlerinde mine tabakas\u0131 incedir. \u0130ki ayak \u00fczerinde y\u00fcr\u00fcme potansiyeline sahip oldu\u011fu ileri s\u00fcr\u00fclmektedir. Kafa kaidesindeki bir\u00e7ok \u00f6zellik, foramen magnumun konumu, dik y\u00fcr\u00fcd\u00fc\u011f\u00fcn\u00fcn kan\u0131tlar\u0131d\u0131r. Kafatas\u0131nda ayn\u0131 anda \u015fempenze-goril ve Hominid benzeri \u00f6zellikler g\u00f6stermesi dikkate al\u0131n\u0131rsa, bu t\u00fcr\u00fcn ortak atadan ayr\u0131ld\u0131ktan sonra Hominid y\u00f6n\u00fcnde evrimle\u015fmeye koyulan ilk \u00f6rneklerden biri oldu\u011fu tahmin edilebilir. Bu t\u00fcre ait g\u00f6vde iskeleti ne yaz\u0131k ki bulunamad\u0131. Sahelanthropus \u00e7adensis\u2019in bulundu\u011fu b\u00f6lge Do\u011fu Afrika\u2019daki me\u015fhur Rift Vadisi\u2019nden 2500 km daha do\u011fudad\u0131r.<\/p>\n
Kaynak:<\/strong> Metin \u00d6zbek, 50 Soruda \u0130nsan\u0131n Tarih\u00f6ncesi Evrimi, Bilim ve Gelecek Kitapl\u0131\u011f\u0131, Ocak 2010 s. 77-79<\/p>\n","protected":false},"excerpt":{"rendered":" Son y\u0131llarda Afrika\u2019n\u0131n \u00f6zellikle kuzeydo\u011fusunda ve do\u011fusunda \u00c7ad ile Kenya s\u0131n\u0131rlar\u0131 i\u00e7inde g\u00fcn \u0131\u015f\u0131\u011f\u0131na \u00e7\u0131kar\u0131lan hominid buluntular\u0131 insan ailesinin evrimindeki kay\u0131p halkalar konusunda bilim adamlar\u0131n\u0131 yeni bir tart\u0131\u015fma ortam\u0131na \u00e7ekti. 2000\u2019li y\u0131llardan itibaren atalar\u0131m\u0131z\u0131n evrim galerisine yeni hominid\u2019ler eklendi. \u0130nsan cinsi \u00f6ncesindeki ailemizin temsilcisinin sadece Australopitekus olmad\u0131\u011f\u0131n\u0131 bu \u00f6nemli ke\u015fiflerle anl\u0131yoruz. Ardipitekus, Sahelanthropus ve Orrorin […]<\/p>\n","protected":false},"author":429,"featured_media":38451,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19],"tags":[242,200,816,5469,555,5575],"class_list":["post-38450","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","tag-anatomi","tag-evrim","tag-fosil","tag-hominid","tag-insan","tag-sempaze"],"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