Just as Holmberg believed, the Sirionó were among the most culturally impoverished people on earth. But this was not because they were unchanged holdovers from humankind’s ancient past but because smallpox and influenza laid waste to their villages in the 1920s. Before the epidemics at least three thousand Sirionó, and probably many more, lived in eastern Bolivia. By Holmberg’s time fewer than 150 remained—a loss of more than 95 percent in less than a generation.
