May 2, 2024

Bloodlines and Bloodsuckers: Tracing Human Migration and Colonization in the Americas Through Lice

The human louse is a wingless, blood-sucking parasite that lives its whole life on its host. Due to this intimate relationship, studying lice can provide hints to how human beings progressed. In the new research study, scientists analyzed the hereditary variation in 274 human lice from 25 geographical websites around the world.

A genetic analysis based on louse DNA exposed the presence of two unique clusters of lice that seldom interbred. The patterns observed in the brand-new research study assistance existing concepts about human migration and offer additional knowledge about how lice have evolved.

Genetic Clusters Reveal Migration Patterns
A genetic analysis based upon louse DNA revealed the presence of 2 distinct clusters of lice that rarely interbred. Cluster I had an around the world distribution, while cluster II was found in Europe and the Americas. The only lice with origins from both clusters are discovered in the Americas. This unique group appears to be the result of a mixture in between lice came down from populations that got here with the First People and those descended from European lice, which were brought over during the colonization of the Americas.
Connect Between Central and asian American Lice
The researchers also identified a hereditary relationship in between lice in Asia and Central America. This supports the concept that individuals from East Asia migrated to North America and became the first Native Americans. These people then spread out south into Central America, where modern louse populations today still maintain a genetic signature from their distant Asian ancestors.
Future Research and Conclusions
The patterns observed in the brand-new study assistance existing concepts about human migration and provide additional understanding about how lice have actually developed. The scientists point out that they chose genetic markers that evolve rapidly and are best suited to recent events.
The authors add: “Human lice are more than bothersome human parasites, they are satellites of our evolution. Because human lice feed upon human blood, they require us to endure, and over countless years this led to a long co-evolutionary history together.”
Recommendation: “Nuclear hereditary diversity of head lice clarifies human dispersal around the world” by Marina S. Ascunce, Ariel C. Toloza, Angélica González-Oliver and David L. Reed, 8 November 2023, PLOS ONE.DOI: 10.1371/ journal.pone.0293409.

Contact between Europeans and Native Americans is recorded in the DNA of head lice. Credit: Vincent Smith, Natural History Museum, London, CC-BY 4.0
Global genetic research study of lice recommends they showed up two times in the New World on human hosts.
A brand-new analysis of lice hereditary diversity suggests that lice concerned the Americas two times– once throughout the very first wave of human migration across the Bering Strait, and again throughout European colonization. Marina Ascunce, currently at the United States Department of Agricultures Agricultural Research Service (USDA-ARS), and coworkers, report these findings in a brand-new study published on November 8 in the open-access journal PLOS ONE.
Lice as Indicators of Human Evolution
The human louse is a wingless, blood-sucking parasite that lives its entire life on its host. It is among the earliest known parasites to live on humans, and the two species have actually coevolved for millennia. Due to this intimate relationship, studying lice can provide clues to how human beings evolved too. In the brand-new research study, scientists examined the genetic variation in 274 human lice from 25 geographical websites worldwide.