Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Hanyar wucewa: Ana samun jan gashi sosai a gefen arewa da yammacin Turai; ya ta'allaka ne a kusa da yawan jama'a a Tsibirin Biritaniya. Redheads a yau ana danganta su da al'ummomin Celtic.A Ireland, an kiyasta yawan mutanen da ke da gashin gashi a kusan kashi 10%, wanda ya sa ya zama mafi yawan mutanen da ke da gashin gashi a duniya. Dangane da DNA na Ireland, kashi 34.7% na yawan mutanen Irish suna ɗaukar allele don jan gashi, kodayake wannan ba ya fassara kai tsaye cikin haihuwar jarirai masu jan gashi.Scotland ma tana da babban kaso tare da kusan kashi 6% na yawan mutanen da ke da jan gashi, tare da Edinburgh kasancewa babban birnin duniya na jan gashi. Yankin da ya fi yawan jan gashi shi ne kudu maso gabashin Scotland tare da Edinburgh a matsayin wurin da aka fi samun jan gashi. A can, huɗu cikin goma suna ɗauke da ɗaya daga cikin jini uku da aka fi sani da jan gashi. Scotland gabaɗaya tana da kashi mafi girma fiye da Ireland, kashi 36.5 bisa ɗari da 34.7 bisa ga binciken da BritainsDNA ta yi. Ingila tana da yawan jan gashi kusan 4%, tare da kashi 28.5% na yawan mutanen da ke da allele; yayin da a Wales kashi 38% na mutanen Welsh suna ɗauke da allele mai jan gashi. Nazarin 1956 game da launin gashi tsakanin sojojin Burtaniya daga Burtaniya sun gano mafi girman matakan jan gashi a Wales da yankunan iyakar Scotland na Ingila.  Tambaya: Wane yanki ne na Burtaniya ke da yawan mutanen da ke da mafi yawan kwayoyin halittar jan gashi?
Ƙasar Wales