▁evidence ▁four ▁years ▁later . ▁ ▁Te ot ih u ac an ▁w olf d ogs ▁In ▁ 2 0 1 0 , ▁ar che olog ists ▁announced ▁that ▁they ▁had ▁found ▁the ▁remains ▁of ▁w olf - d ogs ▁that ▁had ▁been ▁kept ▁by ▁the ▁war rior ▁class ▁of ▁the ▁Te ot ih u ac an ▁civil ization ▁in ▁Mexico ' s ▁central ▁valley ▁about ▁two ▁thousand ▁years ▁ago , ▁and ▁that , ▁in ▁light ▁of ▁this ▁finding , ▁certain ▁animals ▁commonly ▁dep icted ▁in ▁the ▁art ▁of ▁that ▁culture , ▁which ▁had ▁been ▁thought ▁to ▁be ▁strange ▁dogs ▁or ▁co y otes , ▁are ▁being ▁re - ex am ined . ▁ ▁New ▁World ▁black ▁wol ves ▁ ▁Gen etic ▁research ▁from ▁the ▁Stan ford ▁University ▁School ▁of ▁Medicine ▁and ▁the ▁University ▁of ▁California , ▁Los ▁Angeles ▁revealed ▁that ▁wol ves ▁with ▁black ▁pel ts ▁o we ▁their ▁distinct ive ▁color ation ▁to ▁a ▁mut ation ▁that ▁entered ▁the ▁w olf ▁population ▁through ▁ad mi xture ▁with ▁the ▁domestic ▁dog . ▁Ad olph ▁Mur ie ▁was ▁among ▁the ▁first ▁w olf ▁bi olog ists ▁to ▁spec ulate ▁that ▁the ▁wide ▁color ▁variation ▁in ▁wol ves ▁was ▁due ▁to ▁inter bre eding ▁with ▁dogs ; ▁ ▁In ▁ 2 0 0 8 ▁Dr . ▁Gregory ▁S . ▁Bar sh , ▁a ▁professor ▁of ▁gen et ics ▁and ▁ped iat rics ▁at ▁the ▁Stan ford ▁University ▁School ▁of ▁Medicine ▁used ▁mole cular ▁gen etic ▁techniques ▁to ▁analyze ▁DNA ▁sequences ▁from ▁ 1 5