Wherever mankind tread , head lice come too . Genetic evidence designate that read/write head lice migrated to the Americas double : firstly , when humans first migrated from Eurasia across the Bering Strait and , secondly , when Europeans colonized the Americas around 500 eld ago .
Notorious for causing itchy head word , head lice are a bloodline - suckle parasite that spend their whole lives on the scalp of unsuspicious humans . They ’re likely to be one of the previous parasites of humans and have co - acquire with us for many millennia .
In a new study , scientist plunged into the genetical multifariousness of the top dog lice that inhabit human head across the planet , studying 274 lice from 25 geographic fix around the world . This revealed that head lice can be split up into two clear-cut bunch : one with a worldwide dispersion , and another establish only in Europe and the Americas .
examine profoundly , they institute that the only lice with ancestry from both clustering are establish in the Americas . The researchers argue that this discrete group is the product of a mixture of lice descended from population that arrived with the First People and those descended from European plant louse , brought over during the colonisation of the Americas .
To affirm this theory , the research worker identified a genetic relationship between lice in Asia and Central America . This make sense , as thefirst people to migrateto the Americas were from East Asia , crossing the Bering Land Bridge between advanced - day Alaska and Russia . Once they entered North America , they head in the south into Central America , where advanced louse population today still keep a genetic signature from their upstage Asian ancestors .
In what ’s known as the Columbian central , the two reconnected worlds prolific swap their unique plants , creature , human populations , treasured alloy , ideas , cultures , and – perhaps most significantly – diseases . Humble forefront lice , it appears , were also part of this delimitate moment in history .
The researcher explicate that promontory lice are extremely useful tool for learn human history and development . For this subject , they concentre on rapidly evolve genetic marking that can illuminate more recent story . However , they speculate that slower - changing markers could be utilize to peer back even deeply in time .
“ Human lice are more than annoying human parasites , they are ‘ satellite ’ of our organic evolution . Because human louse provender on human parentage , they need us to exist , and over millions of year this leave in a farseeing co - evolutionary history together , ” the study generator say in astatement .
The new study is issue in the journalPLOS ONE .
