Cilt renginin evrimi konusunda her zaman itibarl\u0131 olan bir teori s\u00fcrekli bir ger\u00e7eklik kazanm\u0131\u015f gibi g\u00f6r\u00fcn\u00fcyor.<\/p>\n
Koyu ten rengi, UV \u0131\u015f\u0131nlar\u0131n\u0131n etkisini azaltarak cilt kanserinden korunmada bireysel bir fayda sa\u011fl\u0131yor. A\u00e7\u0131k renk tenliler, koyu tenlilere g\u00f6re en \u00f6nemli 3 cilt kanseri tipine a\u015fa\u011f\u0131 yukar\u0131 1000 kez fazla yakalan\u0131yorlar. Ancak ara\u015ft\u0131rmac\u0131lar y\u0131llard\u0131r bu bilginin do\u011fal se\u00e7ilime kar\u015f\u0131l\u0131k gelmedi\u011fini, tesad\u00fcfi risk azl\u0131\u011f\u0131 oldu\u011funu d\u00fc\u015f\u00fcn\u00fcyorlard\u0131.<\/p>\n
Darwin\u2019in bile adaptasyon \u00f6zelli\u011fi olarak g\u00f6rmedi\u011fi bu pigment olu\u015fumu, yeni ara\u015ft\u0131rmalara g\u00f6re evrimsel bir ger\u00e7eklik olarak kar\u015f\u0131m\u0131za \u00e7\u0131kacak gibi duruyor.<\/p>\n
Bulgular ekvatoryal Afrika\u2019da ya\u015fayan ve d\u00fcnya \u00fczerindeki en y\u00fcksek UV \u0131\u015f\u0131nlar\u0131na maruz kalan albinolar \u00fczerinde yap\u0131lan \u00e7al\u0131\u015fmadan elde edildi. \u00c7al\u0131\u015fma t\u0131bbi kay\u0131tlara dayan\u0131yordu ve bu b\u00f6lgede ya\u015fayan albinolar\u0131n y\u00fczde 80 inden fazlas\u0131 30 ya\u015f\u0131ndan \u00f6nce cilt kanserine yakalanm\u0131\u015f oluyorlard\u0131. Bunun sonucu olarak da a\u00e7\u0131k renk tenliler koyulara g\u00f6re daha k\u0131sa s\u00fcrede ve genellikle en d\u00fc\u015f\u00fck \u00fcreme oran\u0131yla \u00f6l\u00fcyorlard\u0131.<\/p>\n
Ara\u015ft\u0131rmaya kat\u0131lan biliminsanlar\u0131, en yak\u0131n akrabalar\u0131m\u0131z olan \u015fempanzeler ve ilk insan\u0131n pheomelaninden dolay\u0131 (cilde ve t\u00fcylere sar\u0131-k\u0131z\u0131l rengi veren) soluk renkli t\u00fcyleri oldu\u011funu d\u00fc\u015f\u00fcn\u00fcyorlard\u0131. Atalar\u0131m\u0131z t\u00fcylerini kaybetmeye ba\u015flad\u0131klar\u0131nda, Afrika \u00e7ay\u0131rlar\u0131ndaki y\u00fcksek s\u0131cakl\u0131k onlar\u0131 cilt kanserine kar\u015f\u0131 y\u00fcksek risk alt\u0131nda b\u0131rakacakt\u0131.<\/p>\n
Ancak yava\u015f yava\u015f eumelanin (sa\u00e7a ve deriye kahverengi siyah rengi veren pigment) \u00fcretimine do\u011fru evrimle\u015fme oldu\u011funda, UV \u0131\u015f\u0131nlar\u0131n\u0131n hasarlar\u0131ndan ve buna ba\u011fl\u0131 olarak cilt kanserinden korunulmaya ba\u015flanm\u0131\u015ft\u0131. Eumelanin ayr\u0131ca DNA hasar\u0131na kar\u015f\u0131 da do\u011fal bir koruma sa\u011fl\u0131yordu. Koyu renkli ilk insanlar daha az cilt kanserine yakaland\u0131klar\u0131 i\u00e7in, erken \u00f6l\u00fcmler azald\u0131k\u00e7a \u00fcreme potansiyelleri de \u00f6nemli \u00f6l\u00e7\u00fcde artm\u0131\u015f oluyordu.<\/p>\n
Proceedings of the Royal Society B<\/em>\u2019de yay\u0131mlanan bu ara\u015ft\u0131rmaya g\u00f6re, koyu ten rengi 1. 2-1. 8 milyon y\u0131l \u00f6nce ekvatoryal Afrika\u2019da h\u0131zla artm\u0131\u015ft\u0131. Ayn\u0131 b\u00f6lgede bug\u00fcn bile albinolar\u0131n birincil erken \u00f6l\u00fcm sebebi cilt kanseri olmaktad\u0131r.<\/p>\n","protected":false},"excerpt":{"rendered":" Cilt renginin evrimi konusunda her zaman itibarl\u0131 olan bir teori s\u00fcrekli bir ger\u00e7eklik kazanm\u0131\u015f gibi g\u00f6r\u00fcn\u00fcyor. Koyu ten rengi, UV \u0131\u015f\u0131nlar\u0131n\u0131n etkisini azaltarak cilt kanserinden korunmada bireysel bir fayda sa\u011fl\u0131yor. A\u00e7\u0131k renk tenliler, koyu tenlilere g\u00f6re en \u00f6nemli 3 cilt kanseri tipine a\u015fa\u011f\u0131 yukar\u0131 1000 kez fazla yakalan\u0131yorlar. Ancak ara\u015ft\u0131rmac\u0131lar y\u0131llard\u0131r bu bilginin do\u011fal se\u00e7ilime […]<\/p>\n","protected":false},"author":42,"featured_media":26270,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[159,19,21,32],"tags":[3396,3397,272,200,3398],"class_list":["post-26269","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-122-sayi","category-bilim-gundemi","category-biyoloji","category-evrim","tag-cilt","tag-cilt-rengi","tag-dna","tag-evrim","tag-pheomelanin"],"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