Two million years ago, human ancestors were small-brained hominins already hunting large game with coordinated technique, not scavenging carcasses left by lions and leopards. Anthropologist Henry Bunn of the University of Wisconsin lays out the case at a European Society for the Study of Human Evolution conference, using a butchery site in Tanzania where antelope, gazelle, and wildebeest bones show marks from deliberate ambush kills. The film sets this against the previous benchmark, a 400,000-year-old German site where spear marks on horse bones had stood as the oldest solid evidence of human hunting. Bunn compares the species of prey killed by modern lions and leopards to what shows up in the ancient butchery remains, arguing the pattern only makes sense if early humans were choosing and killing specific animals themselves. The stakes go beyond hunting: the shift to a meat-rich diet, the film argues, freed up energy once spent on digestion and helped fuel the brain growth that followed over the next two million years.