Three great apes are all part of the world’s longest-running gorilla study — a project begun in 1967 by famed American primatologist Dian Fossey. Yet Fossey herself, who died in 1985, would likely be surprised any mountain gorillas are still left to study. Alarmed by rising rates of poaching and deforestation in central Africa, she predicted the species could go extinct by 2000. Instead, a concerted and sustained conservation campaign has averted the worst and given a second chance to these great apes, which share about 98% of human DNA. Last fall, the Switzerland-based International Union for Conservation of Nature changed the status of mountain gorillas from “critically endangered” to “endangered,” an improved if still-fragile designation.