Date:

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.

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.

- Advertisement -

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.

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.”


PLOS ONE

https://doi.org/10.1371/journal.pone.0293409

Header Image Credit : PLOS ONE

- Advertisement -
Mark Milligan
Mark Milligan
Mark Milligan is an 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 and the BCA Medal of Honour.

Mobile Application

spot_img

Related Articles

Clusters of ancient qanats discovered in Diyala

An archaeological survey has identified three clusters of ancient qanats in the Diyala Province of Iraq.

16,800-year-old Palaeolithic dwelling found in La Garma cave

Archaeologists have discovered a 16,800-year-old Palaeolithic dwelling in the La Garma cave complex, located in the municipality of Ribamontán al Monte in Spain’s Cantabria province.

Burials found in Maya chultun

Archaeologists from the National Institute of Anthropology and History (INAH) have uncovered burials within a chultun storage chamber at the Maya city of Ek' Balam.

Archaeologists analyse medieval benefits system

Archaeologists from the University of Leicester have conducted a study in the main cemetery of the hospital of St. John the Evangelist, Cambridge, to provide new insights into the medieval benefits system.

Major archaeological discoveries in Mecklenburg-Western Pomerania

In an announcement by the State Office for Culture and Monument Preservation (LAKD), archaeologists excavating in the German state of Mecklenburg-Western Pomerania have uncovered seven Bronze Age swords, 6,000 silver coins, and two Christian reliquary containers.

Early humans hunted beavers 400,000-years-ago

Researchers suggests that early humans were hunting, skinning, and eating beavers around 400,000-years-ago.

Archaeologists find burial bundles with carved masks

A team of archaeologists from the PUCP Archaeology Program “Valley of Pachacámac” have uncovered over 70 intact burial bundles with carved masks.

Should the Elgin Marbles be returned?

The Elgin marbles are a collection of decorative marble sculptures taken from the temple of Athena (the Parthenon) on the Acropolis in Athens.