▁are ▁un ited ▁in ▁the ▁single ▁genus ▁Con no cha etes , ▁with ▁the ▁black ▁w ilde be est ▁being ▁named ▁( C . ▁g nou ) ▁and ▁the ▁blue ▁w ilde be est ▁( C . ▁t aur inus ). ▁ ▁According ▁to ▁a ▁mit och ond rial ▁DNA ▁analysis , ▁the ▁black ▁w ilde be est ▁are ▁estimated ▁to ▁have ▁diver ged ▁from ▁the ▁main ▁line age ▁during ▁the ▁Middle ▁Ple ist oc ene ▁and ▁became ▁a ▁distinct ▁species ▁around ▁a ▁million ▁years ▁ago . ▁A ▁diver gence ▁rate ▁around ▁ 2 % ▁has ▁been ▁calculated . ▁The ▁split ▁does ▁not ▁seem ▁to ▁have ▁been ▁driven ▁by ▁competition ▁for ▁resources , ▁but ▁instead ▁because ▁each ▁species ▁adopted ▁a ▁different ▁e colog ical ▁n iche ▁and ▁occupied ▁a ▁different ▁tro ph ic ▁level . ▁ ▁Blue ▁w ilde be est ▁foss ils ▁d ating ▁back ▁some ▁ 2 . 5 ▁million ▁years ▁ago ▁are ▁common ▁and ▁w ides p read . ▁They ▁have ▁been ▁found ▁in ▁the ▁foss il - b ear ing ▁c aves ▁at ▁the ▁C rad le ▁of ▁Hum ank ind ▁north ▁of ▁Johannes burg . ▁Else where ▁in ▁South ▁Africa , ▁they ▁are ▁pl ent iful ▁at ▁such ▁sites ▁as ▁E land sf onte in , ▁Corn elia , ▁and ▁Flor is bad . ▁The ▁earliest ▁foss ils ▁of ▁the ▁black ▁w ilde be est ▁were ▁found ▁in ▁sed iment ary ▁rock ▁in ▁Corn elia ▁in ▁the ▁Orange ▁Free ▁State ▁and ▁dated ▁back ▁about ▁ 8 0 0