▁can ▁date ▁back ▁thousands ▁of ▁years . ▁A ▁ 2 0 0 5 ▁study ▁compared ▁the ▁mit och ond rial ▁DNA ▁sequences ▁of ▁modern ▁wol ves ▁with ▁those ▁from ▁thirty - four ▁spec im ens ▁dated ▁between ▁ 1 8 5 6 ▁and ▁ 1 9 1 5 . ▁The ▁historic ▁population ▁was ▁found ▁to ▁possess ▁twice ▁the ▁gen etic ▁divers ity ▁of ▁modern ▁wol ves , ▁which ▁suggests ▁that ▁the ▁m D NA ▁divers ity ▁of ▁the ▁wol ves ▁er adic ated ▁from ▁the ▁western ▁US ▁was ▁more ▁than ▁twice ▁that ▁of ▁the ▁modern ▁population . ▁Some ▁ha plot ypes ▁possessed ▁by ▁the ▁Mexican ▁w olf , ▁the ▁ext inct ▁Great ▁Pla ins ▁w olf , ▁and ▁the ▁ext inct ▁Southern ▁Rock y ▁Mountain ▁w olf ▁were ▁found ▁to ▁form ▁a ▁unique ▁" s ou thern ▁cla de ". ▁All ▁North ▁American ▁wol ves ▁group ▁together ▁with ▁those ▁from ▁E uras ia , ▁except ▁for ▁the ▁southern ▁cla de ▁which ▁form ▁a ▁group ▁exclusive ▁to ▁North ▁America . ▁The ▁wide ▁distribution ▁area ▁of ▁the ▁southern ▁cla de ▁indicates ▁that ▁gene ▁flow ▁was ▁extensive ▁across ▁the ▁recognized ▁limits ▁of ▁its ▁sub species . ▁ ▁In ▁ 2 0 1 6 , ▁a ▁study ▁of ▁mit och ond rial ▁DNA ▁sequences ▁of ▁both ▁modern ▁and ▁ancient ▁wol ves ▁generated ▁a ▁ph y log en etic ▁tree ▁which ▁indicated ▁that ▁the ▁two ▁most ▁bas al ▁North ▁American ▁ha plot ypes ▁included ▁the ▁Mexican ▁w olf ▁and ▁the ▁V ancouver ▁Island ▁w olf . ▁ ▁In