At Ngorongoro crater a herd of zebra and wildebeests (also known as gnus) graze. Tonight on #ExpeditionUnknown, Josh Gates (gatesygram) explores the roots of humanity in Tanzania where some of the earliest evidence of our ancestors have been found. . #africa #archeology #wildlifephotography #adventureisoutthere #safari #ngorongorocrater #tanzania #serengeti