LAUSR

Times are hard for the Hadza of Tanzania, who include some of the last people on the planet to live as nomadic hunter-gatherers. Their way of life has been a magnet for researchers for 60 years, and the subject of hundreds of scholarly papers, because it may offer the closest analog to the way our African ancestors lived. A few maintain their iconic lifestyle. But their Brooklyn-size territory is being encroached on by pastoralists whose cattle drink their water and graze on their grasslands, farmers clearing woodlands to grow crops, and climate change that dries up rivers and stunts grass. Researchers wonder about their responsibilities to the people they have studied intensively for decades, and many are seeking ways to help, even as they vie to study the few Hadza who still hunt and gather full time. But some researchers have stopped fieldwork altogether, saying the Hadza lifestyle has changed too much.