0 ▁wol ves , ▁half ▁of ▁them ▁black , ▁in ▁Y ellow stone ▁National ▁Park , ▁which ▁covers ▁parts ▁of ▁Wy oming , ▁Mont ana ▁and ▁Id aho . ▁It ▁was ▁discovered ▁that ▁a ▁gene ▁mut ation ▁responsible ▁for ▁the ▁protein ▁beta - def ens in ▁ 3 ▁ ▁is ▁responsible ▁for ▁the ▁black ▁coat ▁color ▁in ▁dogs . ▁After ▁finding ▁that ▁the ▁same ▁mut ation ▁was ▁responsible ▁for ▁black ▁wol ves ▁in ▁North ▁America ▁and ▁the ▁Italian ▁Ap enn ines , ▁he ▁set ▁out ▁to ▁discover ▁the ▁origin ▁of ▁the ▁mut ation . ▁Bar sh ▁and ▁his ▁colle agues ▁concluded ▁that ▁the ▁mut ation ▁arose ▁in ▁dogs ▁ 1 3 , 0 0 0 ▁to ▁ 1 2 0 , 0 0 0 ▁years ▁ago , ▁with ▁a ▁preferred ▁date ▁of ▁ 4 7 , 0 0 0 ▁years ▁ago ▁after ▁comparing ▁large ▁sections ▁of ▁w olf , ▁dog , ▁and ▁co y ote ▁genom es . ▁At ▁the ▁University ▁of ▁California , ▁Los ▁Angeles , ▁Robert ▁K . ▁Wayne , ▁a ▁can ine ▁evolution ary ▁bi ologist , ▁stated ▁that ▁he ▁believed ▁that ▁dogs ▁were ▁the ▁first ▁to ▁have ▁the ▁mut ation . ▁He ▁further ▁stated ▁that ▁even ▁if ▁it ▁originally ▁arose ▁in ▁E uras ian ▁wol ves , ▁it ▁was ▁passed ▁on ▁to ▁dogs ▁who , ▁soon ▁after ▁their ▁arrival , ▁brought ▁it ▁to ▁the ▁New ▁World ▁and ▁then ▁passed ▁it ▁to ▁wol ves ▁and ▁co y otes . ▁Black ▁wol ves ▁with ▁recent ▁dog ▁ancest ry ▁tend ▁to ▁retain