There are other people, however, who do ponder the Hadza's future. Officials in the Tanzanian government, for starters. Tanzania is a future-oriented nation, anxious to merge into the slipstream of the global economy. Baboon-hunting bushmen is not an image many of the country's leaders wish to project. One minister has referred to the Hadza as backward. Tanzania's president, Jakaya Kikwete, has said that the Hadza "have to be transformed." The government wants them schooled and housed and set to work at proper jobs.

Even the one Hadza who has become the group's de facto spokesperson, a man named Richard Baalow, generally agrees with the government's aims. Baalow, who adopted a non-Hadza first name, was one of the first Hadza to attend school. In the 1960s his family lived in government-built housing—an attempt at settling the Hadza that soon failed. Baalow, 53, speaks excellent English. He wants the Hadza to become politically active, to fight for legal protection of their land, and to seek jobs as hunting guides or park rangers. He encourages Hadza children to attend the regional primary school that provides room and board to Hadza students during the academic year, then escorts them back to the bush when school is out.

The school-age kids I spoke with in Onwas's group all said they had no interest in sitting in a classroom. If they went to school, many told me, they'd never master the skills needed for survival. They'd be outcasts among their own people. And if they tried their luck in the modern world—what then? The women, perhaps, could become maids; the men, menial laborers. It's far better, they said, to be free and fed in the bush than destitute and hungry in the city.

More Hadza have moved to the traditionally Hadza area of Mangola, at the edge of the bush, where, in exchange for money, they demonstrate their hunting skills to tourists. These Hadza have proved that their culture is of significant interest to outsiders and a potential source of income. Yet among the Hadza of Mangola there has also been a surge in alcoholism, an outbreak of tuberculosis, and a distressing rise in domestic violence, including at least one report of a Hadza man who beat his wife to death.

Though the youngsters in Onwas's group show little interest in the outside world, the world is coming to them. After two million years, the age of the hunter-gatherer is over. The Hadza may hold on to their language; they may demonstrate their abilities to tourists. But it's only a matter of time before there are no more traditional Hadza scrambling in the hills with their bows and arrows, stalking baboons.

Up on the hill Onwas has led us to, clutching my knife, I crouch behind Maduru as the baboon moves along a fin of rock. And then, abruptly, the baboon stops. He swivels his head. He is so close we could reach out to each other and make contact. I stare into his eyes, too frightened to even blink. This lasts maybe a second. Maduru doesn't shoot, possibly because the animal is too close and could attack us if wounded—it's often the poison, not the arrow, that kills. An instant later the baboon leaps away into the bushes.