Amehlo aluhlaza kubangelwa ukuguqulwa komzimba

Ososayensi baqagela nje lapho kwenzeka ukuguqulwa komzimba, futhi lo muntu wayenamehlo aluhlaza okwesibhakabhaka, kodwa ezinye izibonakaliso zibonisa ukuthi, kungenzeka ukuthi kwenzeka eminyakeni emashumi edlule edlule. Phakathi nalesi sikhathi kwakunabantu abaningi baseYurophu, njengoba ezolimo zaseMpumalanga Ephakathi zaqala ukusakazwa emazweni aseYurophu.

Umsuka

Umagazini i-Human Genetics wabhala inothi ngabososayensi ukuthi ukuguqulwa okubangelwa ukubonakala kwamehlo aluhlaza okwesibhakabhaka cishe kwenzeka enyakatho-ntshonalanga ye-Black Sea esifundeni.

UProfesa Eyberg waphawula ukuthi "ngokuzenzakalelayo" umbala wamehlo omuntu kufanele ube mnyama. Amehlo aluhlaza okwesibhakabhaka umphumela wokuguqulwa komzimba, ngoba isikhumba somnyama esikhumbeni siwu-melanin, sithinta ukubonakala kwezinsana ezinamabala aluhlaza. Nokho, eNyakatho Yurophu, isakhi se-OCA2 sinezinguquko eziphazamisa ukukhiqizwa kwe-melanin e-iris, okwaholela ekubukeni kombala okwesibhakabhaka.

UProfesa Eyberg uthe konke okwakubonakala kunamehlo aluhlaza ekuqaleni, kepha ukuguqulwa kwama-chromosomes ethu wegciwane le-OCA2 kubangele "ukuguqulwa" okuye "kwavala" ikhono labantu lokuveza insaba.

Ku-iris, inani le-melanin lihluka, ngakho-ke ama-shades ama-brown ahlukile. Amehlo aluhlaza anabantu abanobukhokho obufanayo abashintsha isakhi. Bonke bazuze i-mutation efanayo ye-DNA yabo.

Amadoda nabesifazane abanamehlo aluhlaza okwesibhakabhaka banokulandelana okufana nalokho okuphathelene nezofuzo zaleyo ngxenye ye-molecule ye-DNA enesibopho sombala.

UProf. Eyberg wenza ukuhlaziywa kwe-DNA yabantu abangaphezu kuka-800, kusukela kumhlophe ama-blondes aseScandinavia kubantu abanesikhumba esimnyama, kodwa ngamehlo aluhlaza okwesibhakabhaka ehlala eTurkey naseJordani. Ukuhlolwa kwakhe kuqinisekisile umbono wekhokho oyedwa ovamile.

Akucaci ukuthi kungani amehlo eluhlaza okwesibhakabhaka ejwayelekile phakathi kwabantu baseNingizimu aseRussia naseNyakatho Yurophu. Ngaphambili kwakucatshangwa ukuthi lesi sici sinikeza inzuzo ebusika obusika behlobo noma e-polar ebusika. Mhlawumbe lokhu kubhekwa njengokukhangayo futhi, ngakho-ke, okuhle kakhulu ekukhethweni ngokobulili.

Izici

Ngokwemvelo, iris ihlanganisa uhlaka lwe-ectoderm ne-mesodermal. Indlela i-pigment isakazwa kuyo, futhi umbala uncike. Ama-Chromatophores asatshalaliswa kumgca we-mesodermal, aqukethe i-melanin. Ingqimba yangemuva iqukethe amaseli amaningi e-pigment agcwele i-fuscin. Ama-fiber kanye nezitsha ze-iris nazo zidlala indima.

Imibala elula yokukhanya iluhlaza okwesibhakabhaka, i-blue ne-gray.

Ingqimba ye-ectodermal ibonakala ngombala omnyama okwesibhakabhaka. Uma izintambo zangaphandle ze-iris zinomqondo ophansi futhi ophansi we-melanin, ukukhanya okuphezulu kwe-frequency kubanjwe ungqimba lwe-mesodermal, futhi ukukhanya okuphansi kwe-frequency kubonakala kuyo. Amehlo aluhlaza okwesibhakabhaka.

Kukhona abantu abaphupha ngokushintsha umbala wabo wemvelo ube blue. Bakholelwa ukuthi ukubukeka ngesikhathi esifanayo kuzothola ubuhle, ukujula nokucebile. Ngokuvamile, amehlo aluhlaza alukhangayo, izithombe zabantu abanobuhlaza zingahlotshwa ngokusebenzisa ezinye izinhlelo, ikakhulukazi, izithombehop. Ngemva kokuhlola imiphumela yekhompiyutha, ungathatha ukwakheka kwakho kanye nokwenza kahle.