{"id":14093,"date":"2017-01-01T12:35:02","date_gmt":"2017-01-01T09:35:02","guid":{"rendered":"http:\/\/109.232.216.219\/~bilimvegelecek\/?p=14093"},"modified":"2018-02-08T16:23:21","modified_gmt":"2018-02-08T13:23:21","slug":"sanayi-melanizmi-ve-kuslar-en-guclu-aciklama","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2017\/01\/01\/sanayi-melanizmi-ve-kuslar-en-guclu-aciklama","title":{"rendered":"Sanayi melanizmi ve ku\u015flar: En g\u00fc\u00e7l\u00fc a\u00e7\u0131klama"},"content":{"rendered":"

B.betularia\u2019n\u0131n siyah formlar\u0131ndaki art\u0131\u015f\u0131n nedeninin beyaz formlar\u0131n ku\u015flar taraf\u0131ndan daha kolay avlanmas\u0131 oldu\u011fu izah\u0131na baz\u0131 ele\u015ftiriler getirilmi\u015fti. Michael Majerus\u2019un \u00f6l\u00fcm\u00fcnden sonra yay\u0131nlanan \u00e7al\u0131\u015fmas\u0131 bu izah\u0131n do\u011fru oldu\u011funu g\u00f6steriyor. <\/em><\/p>\n

19.\u00a0y\u00fczy\u0131l \u0130ngiltere\u2019sindeki sanayile\u015fmenin yaratt\u0131\u011f\u0131, 20. y\u00fczy\u0131l\u0131n son \u00e7eyre\u011fine dek uzanan \u00e7evresel kirlenmenin ayak izlerini takip eden Biston betularia<\/em>\u2019daki sanayi melanizminin evrimini \u00f6zetledi\u011fimiz yaz\u0131m\u0131z\u0131n son k\u0131sm\u0131na gelmi\u015f bulunuyoruz. Yaz\u0131m\u0131n\u0131n ilk b\u00f6l\u00fcm\u00fcnde, modern evrimsel geneti\u011fin \u00f6nerilen ilk do\u011fal se\u00e7ilim \u015fiddeti hesaplamalar\u0131nda kullan\u0131lan bu \u00e7arp\u0131c\u0131 evrimle\u015fme olgusunun, genetik temeli siyah (Carbonaria), beyaz\u0131ms\u0131 ve insularia ad\u0131 verilen ara renk durumlu \u015feklinde g\u00f6r\u00fcn\u00fcr k\u0131l\u0131nan v\u00fccut rengi varyantlar\u0131n y\u00fczy\u0131l\u0131 a\u015fk\u0131n bir s\u00fcrede g\u00f6r\u00fclen bir s\u0131kl\u0131k de\u011fi\u015fimiyle tan\u0131mlad\u0131\u011f\u0131ndan s\u00f6z etmi\u015ftik. M\u00fcze \u00f6rneklerinin g\u00f6sterdi\u011fi \u00fczere, 19. y\u00fczy\u0131l\u0131n ikinci yar\u0131s\u0131n\u0131n hemen ba\u015flar\u0131nda s\u0131kl\u0131\u011f\u0131 y\u00fckselmeye ba\u015flayan carbonaria formunun, sanayile\u015fmenin getirdi\u011fi kirlenmeyi takip ederek bu y\u00fczy\u0131l sonlar\u0131nda yayg\u0131nl\u0131\u011f\u0131n\u0131n doruk noktas\u0131na ula\u015ft\u0131\u011f\u0131n\u0131 s\u00f6ylemi\u015ftik. Sanayi b\u00f6lgelerindeki kirlenmeyi izleyen bu carbonaria s\u0131kl\u0131k art\u0131\u015f\u0131n\u0131n, 20. y\u00fczy\u0131ldaki, azalan \u00e7evresel kirlenme sebebiyle s\u0131kl\u0131\u011f\u0131n\u0131n tekrar d\u00fc\u015fmeye ba\u015flamas\u0131 s\u00f6z konusu olmu\u015ftur ve g\u00fcn\u00fcm\u00fcz \u0130ngiltere\u2019sinde carbonarian\u0131n bollu\u011fu 19. y\u00fczy\u0131l\u0131n d\u00fc\u015f\u00fck seviyelerine do\u011fru evrilmeye ba\u015flam\u0131\u015f gibidir. (1)<\/p>\n

Ge\u00e7en ayki yaz\u0131m\u0131zda ise, B.betularia<\/em>\u2019daki bu bariz do\u011fal se\u00e7ilimle evrimle\u015fme olgusunun biyolojik sebeplerine \u0131\u015f\u0131k tutabilecek temel genetik ve genomik bulgulardan s\u00f6z etmi\u015f, son d\u00f6nem genetik \u00e7al\u0131\u015fmalar\u0131n bu g\u00fcvedeki v\u00fccut renginin \u00e7e\u015fitlili\u011finin genetik temeli a\u00e7\u0131s\u0131ndan ortaya koydu\u011fu en \u015fa\u015f\u0131rt\u0131c\u0131 sonucun, carbonaria, beyaz\u0131ms\u0131 ve insularia formlar\u0131 \u015feklinde g\u00f6r\u00fcnen renk de\u011fi\u015fimlerinin temelinde bilinen melanizm genlerinin yatmamas\u0131 oldu\u011funu s\u00f6ylemi\u015ftik. (2) Genetik \u00e7al\u0131\u015fmalar\u0131n bir di\u011fer heyecan verici sonucu ise, fenotipik yenilik yaratma potansiyelleri \u00fczerine hayli kafa yorulan s\u0131\u00e7ray\u0131c\u0131 genetik elementlerin bir \u00e7e\u015fidinin, sanayi melanizmini meydana getiren carbonaria formunun olu\u015fumuna yol a\u00e7an mutasyonun temelinde yer almas\u0131yd\u0131. (3) B. Betularia<\/em>\u2019daki v\u00fccut rengi varyasyonunun genetik temelinin bu denli derinle\u015ftirilebilmi\u015f olmas\u0131n\u0131n son derece heyecan verici oldu\u011funu hemen vurgulayal\u0131m.<\/p>\n

Neden, ku\u015flar m\u0131?<\/strong><\/p>\n

Bununla birlikte, do\u011fal se\u00e7ilim genetik \u00e7e\u015fitlili\u011fin bir \u015fekilde yans\u0131mas\u0131 durumundaki nihai fenotipler \u00fczerinden i\u015fleyen bir s\u00fcre\u00e7 oldu\u011fundan, B.betularia<\/em>\u2019daki renk varyasyonunun, bu t\u00fcr\u00fcn biyolojisi ve ekolojisi temelinde net bi\u00e7imde tan\u0131mlanmas\u0131 gerekir. \u015eimdi, yaz\u0131m\u0131z\u0131n ilk b\u00f6l\u00fcm\u00fcnde, kirlenmeyi takip eden bu renk evrimle\u015fmesi i\u00e7in \u00f6nerilen evrimsel-ekolojik izaha tekrar bir bakal\u0131m:<\/p>\n

Sanayile\u015fme ile ba\u015flayan hava kirlili\u011fi sonucunda, sanayi merkezleri civar\u0131ndaki a\u011fa\u00e7l\u0131k alanlarda ve ormanlardaki a\u011fa\u00e7lar\u0131n g\u00f6vdelerini kaplayan likenler \u00f6l\u00fcp kararm\u0131\u015flard\u0131r. Biston betularia<\/em>\u2019n\u0131n a\u00e7\u0131k renkli formlar\u0131n\u0131n t\u00fcnedi\u011fi a\u011fa\u00e7lar\u0131n normalde a\u00e7\u0131k renkli olan g\u00f6vdelerinin kararmas\u0131, a\u00e7\u0131k renkli formlar\u0131n avc\u0131 ku\u015flarca kolayca fark edilmesine yol a\u00e7arken, siyah renkli formlar art\u0131k koyula\u015fm\u0131\u015f g\u00f6vdelerde kolayl\u0131kla kamufle olmu\u015flar ve b\u00f6ylece avc\u0131lardan korunmu\u015flard\u0131r. Bu durum, yayg\u0131n form olan beyaz\u0131ms\u0131lar\u0131n sanayi merkezlerinde t\u00fckenmelerine yol a\u00e7arken siyah formlar\u0131n ku\u015faklar boyu art\u0131\u015f\u0131n\u0131 sa\u011flam\u0131\u015ft\u0131r.<\/p>\n

Ancak bu olduk\u00e7a makul g\u00f6z\u00fcken a\u00e7\u0131klama birka\u00e7 nokta itibar\u0131yla \u015f\u00fcpheli bir hal de almaktayd\u0131: \u00d6ncelikle, B.betularia<\/em> ve di\u011fer kelebek ve g\u00fcve t\u00fcrlerindeki koyu renkli formlar\u0131n sanayile\u015fme ile birlikte avantajl\u0131 k\u0131l\u0131nd\u0131\u011f\u0131 g\u00f6r\u00fc\u015f\u00fcne odaklanan \u00e7o\u011fu \u00e7al\u0131\u015fmada, canl\u0131 ya da \u00f6l\u00fc kelebek-g\u00fcve \u00f6rnekleri a\u011fa\u00e7 g\u00f6vdelerine tutturulmu\u015ftu. Ayr\u0131ca, kirlilik d\u00fczeyi a\u00e7\u0131s\u0131ndan farkl\u0131l\u0131k g\u00f6steren b\u00f6lgeler aras\u0131nda, siyah ya da a\u00e7\u0131k renkli formlar\u0131n g\u00f6\u00e7leri meselesi de \u00e7ok fazla \u00fczerinde durulmayan ancak s\u0131kl\u0131k b\u00fcy\u00fckl\u00fcklerini etkileyebilecek \u00f6nemli bir unsurdu. (4) Bunlara ek olarak, sanayile\u015fmenin bulunmad\u0131\u011f\u0131 yerlerde, kirlenmeye dayal\u0131 se\u00e7ilim \u015fiddeti b\u00fcy\u00fckl\u00fc\u011f\u00fcn\u00fcn teorik hesaplamalar\u0131ndan beklenilmeyecek bir oranda siyah renkli form yer almakta ya da herhangi bir \u00e7evresel manip\u00fclasyon i\u00e7ermeyen laboratuvar deneylerinde siyah formun a\u00e7\u0131k renkli olanlara g\u00f6re uyum ba\u015far\u0131s\u0131 daha y\u00fcksek \u00e7\u0131kmaktayd\u0131. B\u00fct\u00fcn bu noktalardan bak\u0131ld\u0131\u011f\u0131nda, sanayiye dayal\u0131 kirlenme-melanizmin se\u00e7ilimsel y\u00fckseli\u015fi gibi bir do\u011frusal ili\u015fkinin, ku\u015flar\u0131n g\u00fcveleri avlamas\u0131 \u00fczerinden kurulmas\u0131 hayli sorunlu g\u00f6z\u00fckmekteydi.<\/p>\n

\"\"Majerus\u2019un \u00e7al\u0131\u015fmas\u0131<\/strong><\/p>\n

Do\u011fal se\u00e7ilimin bu en parlak ders kitab\u0131 \u00f6rne\u011finin g\u00f6zden d\u00fc\u015f\u00fc\u015f\u00fc y\u00fckseli\u015finden \u00e7ok daha h\u0131zl\u0131 olaca\u011fa benziyordu. Ancak \u015fimdi g\u00f6rece\u011fimiz gibi, sanayi melanizminin ilgili t\u00fcr\u00fcn ekolojisi temelinde evrimsel izah\u0131n\u0131 m\u00fcmk\u00fcn k\u0131lan son g\u00f6zlem ve deneyler, B.betularia<\/em>\u2019daki renk evrimine ili\u015fkin ilk izah\u0131n pek \u00e7ok temel nokta itibar\u0131yla do\u011fru oldu\u011funa i\u015faret ediyor ve b\u00f6ylece do\u011fal se\u00e7ilimle evrimle\u015fmenin bu \u00e7arp\u0131c\u0131 \u00f6rne\u011fi taht\u0131na yeniden kurulmu\u015f oluyor.<\/p>\n

Sanayi melanizmine ili\u015fkin \u015fimdiye kadarki en kapsaml\u0131 ve titiz, y\u00fcksek dikkat ve g\u00f6zlemle ger\u00e7ekle\u015ftirilen \u00e7al\u0131\u015fma, gen\u00e7 ya\u015fta hayat\u0131n\u0131 kaybeden \u0130ngiliz biliminsan\u0131 Michael Majerus\u2019un 6 y\u0131ll\u0131k eme\u011fine dayan\u0131yor. Michael Majerus\u2019un 2009\u2019daki \u00f6l\u00fcm\u00fc nedeniyle yay\u0131nlama f\u0131rsat\u0131 bulamad\u0131\u011f\u0131 bu \u00e7al\u0131\u015fmay\u0131 birka\u00e7 y\u0131l \u00f6nce meslekta\u015flar\u0131 \u00f6zet ama hayli net sonu\u00e7lar veren bir makalede bilim d\u00fcnyas\u0131na sundular. (5)<\/p>\n

Majerus, gece vakti olmak \u00fczere, yakla\u015f\u0131k 5000 g\u00fcveyi i\u015faretleyip farkl\u0131 b\u00f6lgelerde serbest b\u0131rakm\u0131\u015ft\u0131. Majerus\u2019un ve di\u011fer B.betularia<\/em> ara\u015ft\u0131r\u0131c\u0131lar\u0131n\u0131n \u00f6nceki \u00e7al\u0131\u015fmalar\u0131na getirilen \u00f6nemli bir ele\u015ftiri, bu g\u00fcve geceleri aktif oldu\u011fundan, avlanmalar\u0131n\u0131n ku\u015flar yerine yarasalarla ger\u00e7ekle\u015fece\u011fi y\u00f6n\u00fcndeydi. Majerus yapt\u0131\u011f\u0131 deneyler sonucunda, gece b\u0131rak\u0131lan carbonaria ve beyaz\u0131ms\u0131 formlar\u0131n yarasayla avlanma d\u00fczeylerinin ayn\u0131 oldu\u011funu g\u00f6stererek bu ele\u015ftiriyi ge\u00e7ersiz k\u0131lm\u0131\u015ft\u0131. (6)<\/p>\n

Sonu\u00e7 olarak, Michael Majerus, B.betularia<\/em>\u2019daki renk formlar\u0131n\u0131n s\u0131kl\u0131k de\u011fi\u015fimlerinin ku\u015flarla avlanmadan kaynakland\u0131\u011f\u0131na ili\u015fkin \u015fimdiye kadarki en net sonu\u00e7lar\u0131 ise 5000 civar\u0131 g\u00fcveyi kulland\u0131\u011f\u0131 bu son ara\u015ft\u0131rmas\u0131nda ortaya koymu\u015f g\u00f6z\u00fck\u00fcyor: Majerus, kirlenmenin s\u00f6z konusu olmad\u0131\u011f\u0131 b\u00f6lgelerde ger\u00e7ekle\u015ftirdi\u011fi bu deneye dahil etti\u011fi \u00e7e\u015fitli t\u00fcr ve say\u0131daki a\u011fac\u0131n dallar\u0131na, g\u00f6vdelerine ve di\u011fer k\u0131s\u0131mlar\u0131na konan g\u00fcvelere bakt\u0131\u011f\u0131nda, carbonaria formunun beyaz\u0131ms\u0131 forma g\u00f6re ku\u015flar taraf\u0131ndan daha yo\u011fun bi\u00e7imde avland\u0131\u011f\u0131n\u0131 g\u00f6stermi\u015f bulunuyor. Majerus\u2019un 2001-2006 y\u0131llar\u0131n\u0131 kapsayan ve avlanma halindeki dokuz farkl\u0131 ku\u015f t\u00fcr\u00fcn\u00fc de tespit etti\u011fi ara\u015ft\u0131rmas\u0131, carbonaria formunun beyaz\u0131ms\u0131 forma oranla s\u0131kl\u0131\u011f\u0131n\u0131n neredeyse do\u011frusal bir \u015fekilde azald\u0131\u011f\u0131n\u0131 a\u00e7\u0131kl\u0131kla ifade ediyor. Majerus\u2019un verilerinde hesaplanan carbonaria elenme (se\u00e7ilim) katsay\u0131s\u0131 g\u00fcnl\u00fck bazda olmak \u00fczere s<\/em>=0,091. Bu katsay\u0131n\u0131n ku\u015fak ba\u015f\u0131na ald\u0131\u011f\u0131 de\u011fer ise s<\/em>\u2248 0,1-0,2.\u00a0 G\u00f6rece y\u00fcksek bir se\u00e7ilimsel d\u00fczeye i\u015faret eden bu de\u011fer, \u00f6yle g\u00f6r\u00fcl\u00fcyor ki, B.betularia<\/em>\u2019daki v\u00fccut rengi de\u011fi\u015fiminin yar\u0131m as\u0131rdan k\u0131sa bir s\u00fcredeki evrimle\u015fmesini de izah edebilecek b\u00fcy\u00fckl\u00fckte.<\/p>\n

Do\u011fal se\u00e7ilimle evrimle\u015fmenin bu \u00e7arp\u0131c\u0131 \u00f6rne\u011finin biyolojik izah\u0131n\u0131n \u00f6nemli bir k\u0131sm\u0131, b\u00f6ylece, sars\u0131lmas\u0131 m\u00fcmk\u00fcn g\u00f6z\u00fckmeyen bir bi\u00e7imde yap\u0131labilmi\u015fe benziyor. 19. y\u00fczy\u0131l\u0131n ilk yar\u0131s\u0131nda ilk kez ortaya \u00e7\u0131kan bir mutasyon do\u011fal se\u00e7ilime kelebek etkisi yaratarak merak etmeyen akl\u0131n durgun sular\u0131n\u0131 buland\u0131rmaya devam ediyor.<\/p>\n

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

1). L. M. Cook ve IIik.J. Saccheri, The peppered moth and industrial melanism: evolution of a natural selection case study, Heredity<\/em>, 110: 207-212, 2013.<\/p>\n

2) Arjen E. van\u2019t Hof ve Ilik J. Saccheri, Industrial melanism in the peppered moth is not associated with genetic variation in canonical melanisation gene candidates. PLoS ONE 5(5): e10889. doi:10.1371\/journal.pone.0010889, 2010.<\/p>\n

3) Arjen E. van\u2019t Hof, Pascal Campagne, Daniel J. Rigden, Carl J. Yung, Jessica Lingley, Michael A. Quail, Neil Hall, Alistair C. Darby ve Ilik J. Saccheri; The industrial melanism mutation in British peppered moths is a transposable element. Nature<\/em> 534: 102-105, 2016.<\/p>\n

4) Bruce S. Grant, Fine tuning the peppered moth paradigm, Evolution<\/em>, 53: 980-984, 1998.<\/p>\n

5) L. M. Cook, B. S. Grant, I. J. Saccheri ve J. Mallet; Selective bird predation on the peppered moth: the last experiment of Michael Majerus, Biology Letters<\/em>, 8: 609-612, 2012.<\/p>\n

6) Majerus, M. E. N. ; Non-morph specific predation on peppered moths (Biston betularia) by bats. Ecol. Entomol<\/em>. 33, 679 \u2013 683, 2008.<\/p>\n","protected":false},"excerpt":{"rendered":"

B.betularia\u2019n\u0131n siyah formlar\u0131ndaki art\u0131\u015f\u0131n nedeninin beyaz formlar\u0131n ku\u015flar taraf\u0131ndan daha kolay avlanmas\u0131 oldu\u011fu izah\u0131na baz\u0131 ele\u015ftiriler getirilmi\u015fti. Michael Majerus\u2019un \u00f6l\u00fcm\u00fcnden sonra yay\u0131nlanan \u00e7al\u0131\u015fmas\u0131 bu izah\u0131n do\u011fru oldu\u011funu g\u00f6steriyor. 19.\u00a0y\u00fczy\u0131l \u0130ngiltere\u2019sindeki sanayile\u015fmenin yaratt\u0131\u011f\u0131, 20. y\u00fczy\u0131l\u0131n son \u00e7eyre\u011fine dek uzanan \u00e7evresel kirlenmenin ayak izlerini takip eden Biston betularia\u2019daki sanayi melanizminin evrimini \u00f6zetledi\u011fimiz yaz\u0131m\u0131z\u0131n son k\u0131sm\u0131na gelmi\u015f bulunuyoruz. […]<\/p>\n","protected":false},"author":67,"featured_media":14094,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[192,1475,21,32],"tags":[871,200,292,661,1590],"class_list":["post-14093","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-155-sayi","category-bilim-ve-tarih","category-biyoloji","category-evrim","tag-dogalsecilim","tag-evrim","tag-genetik","tag-kuslar","tag-melanizm"],"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