23 November 2023
By Hyun Cho
Head lice, long-time human companions, carry DNA tales of global migrations. Recent research in PLOS ONE reveals that these non-jumping, non-flying scalp dwellers journeyed to the New World with humans—initially from Asia and later via European colonists. Genetic analysis of 274 head lice from 25 locations by evolutionary geneticist Marina Ascunce and team unveiled two distinct clusters—one prevalent in Europe and North America, the other in Asia and Central America. This genetic divide points to historical movements like the migration of humans into the Americas and subsequent European colonization.
Beyond their annoyance, lice provide insights into our shared history. The unexpected genetic split prompts researchers to delve into slowly evolving lice genes for deeper glimpses into human prehistory. The study suggests that exploring lice evolution offers a fast-track perspective on the poorly understood evolutionary history of various host species.