The island of New Guinea was settled by modern human over 50,000 years ago, and is currently characterized by a complex landscape and contains one-seventh of the world's languages. The Eastern Highlands of New Guinea were also the home to the devastating prion disease called kuru that primarily affected Fore-speaking populations, with some 68% of cases involving adult females. We characterized the mitochondrial DNA (mtDNA) diversity of highlanders from Papua New Guinea (PNG) to: (a) gain insight into the coevolution of genes and languages in situ over mountainous landscapes; and (b) evaluate the recent influence of kuru mortality on the pattern of female gene flow.