On the wild river that divides Namibia from Angola, members of the Himba tribe herd cattle as they have done for hundreds of years. But the world of the Himba sits in the shadow of third-world development and the inevitability of change that threatens their way of life; now, they are more likely to attend evangelical church services, congregate around the liquor trader's truck, and pose for tourists' photographs. Sandra Shields and David Campion spent...