Head lice evolution mirrors human migration and colonisation in the Americas

A recent analysis of lice’s genetic diversity suggests that these parasites arrived in the Americas on two distinct occasions: first during the initial human migration across the Bering Strait, and later with the advent of European colonisation.

These research findings were presented by Marina Ascunce and her colleagues, who are currently associated with the USDA-ARS. Their study, published on November 8 in the open-access journal PLOS ONE, illuminates the intricate relationship between lice and human history.

- Advertisement -

The human louse, a wingless, blood-feeding insect that resides exclusively on its human host, has maintained a longstanding coevolutionary connection with our species. It stands as one of the earliest known parasites to thrive on humans, offering valuable insights into the course of human evolution. In their investigation, the scientists scrutinized the genetic diversity among 274 human lice collected from 25 diverse locations worldwide.

A genetic examination, based on louse DNA, disclosed the existence of two distinctive louse groups that infrequently interbred. Cluster I exhibited a global distribution, while cluster II was confined to Europe and the Americas. The sole lice possessing genetic heritage from both clusters were detected in the Americas, forming a unique cohort resulting from the intermingling of lice descended from populations accompanying the First People and lice with European origins, introduced during the colonisation of the Americas.

Furthermore, the researchers established a genetic connection between lice identified in Asia and Central America, corroborating the hypothesis that individuals from East Asia migrated to North America, becoming the earliest Native Americans. Subsequently, they migrated southward into Central America, where modern louse populations still bear a genetic imprint from their distant Asian ancestors.

The observed patterns in this recent study corroborate established theories regarding human migration and contribute supplementary insights into the evolutionary history of lice. The researchers underline their selection of genetic markers that evolve rapidly and are best suited for recent events. Hence, forthcoming studies utilizing markers with a slower evolutionary pace may illuminate more ancient historical episodes. Additionally, the methodologies developed in this study could offer a valuable framework for investigating other host-parasite relationships.

- Advertisement -

The authors add: “Human lice are more than annoying human parasites, they are ‘satellites’ of our evolution. Because human lice feed on human blood, they need us to survive, and over millions of years this resulted in a long co-evolutionary history together.”


Header Image Credit : PLOS ONE

- Advertisement -
Mark Milligan
Mark Milligan
Mark Milligan is multi-award-winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 7,500 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education, the BCA Medal of Honour, and the UK Prime Minister's Points of Light Award.

Mobile Application


Related Articles

Archaeologists uncover 4,200-year-old “zombie grave”

Archaeologists from the State Office for Monument Preservation and Archaeology Saxony-Anhalt have uncovered a "zombie grave" during excavations near Oppin, Germany.

Archaeologists uncover 2,000-year-old clay token used by pilgrims

A clay token unearthed by the Temple Mount Sifting Project, is believed to have served pilgrims exchanging offerings during the Passover festival 2,000-years-ago.

Moon may have influenced Stonehenge construction

A study by a team of archaeoastronomers are investigating the possible connection of the moon in influencing the Stonehenge builders.

Archaeologists explore the resettlement history of the Iron-Age metropolis of Tel Hazor

Archaeologists are conducting a study of the Iron-Age metropolis of Tel Hazor to understand how one of the largest “megacities” of the Bronze Age was abandoned and then resettled.

Excavation uncovers possible traces of Villa Augustus at Somma Vesuviana

Archaeologists from the University of Tokyo have uncovered further evidence of the Villa of Augustus during excavations at Somma Vesuviana.

Study reveals new insights into wreck of royal flagship Gribshunden

Underwater archaeologists from Södertörn University, in collaboration with the CEMAS/Institute for Archaeology and Ancient Culture at Stockholm University, have conducted an investigation of the wreck of the royal flagship Gribshunden.

Microbe X-32 – Is the Plasticene Era coming to an end?

Breaking, a new venture in collaboration with Harvard and the Wyss Institute, is claiming that a new discovery, Microbe X-32, can naturally break down polyolefins, polyesters, and polyamides in just 22 months.

Stone sphere among artefacts repatriated to Costa Rica

395 pre-Columbian artefacts have been repatriated to Costa Rica thanks to a grant by the United States Embassy to the Cultural Agreements Fund.