Scientists have found that head lice on old mummies contains more DNA than teeth. This could be a clue to ancient migration and people.
One team was able to recover the DNA from the cement head lice that were used to stick their eggs on the hairs of South American mummified corpses thousands of years back.
According to the University of Reading’s team, DNA from cement contained a greater amount of DNA than any other method.
It revealed clues about pre-Columbian human migration patterns throughout South America, including that the original population of the San Juan province migrated from the land and rainforests of the Amazon in the North of the continent.
“There’s a search for other sources of ancient DNA, and nit cement may be one of them,” said Dr Mikkel Winther, a study author from University of Copenhagen, Denmark.
Scientists have found that head lice on old mummies contains more DNA than teeth. This could be a clue to ancient migration and people.
They recovered the DNA from head lice eggs, or nits, found in the hair of mummified bodies dating back 1,500 to 2,000 years, and were found in Argentina.
Researchers explained, “This is possible because of the cement that female lice attach eggs to hairs and skin cells on the scalp.”
These findings provide clues to the movement of pre-Columbian South American citizens that aren’t possible through any other method.
This method, they believe, could enable more individual samples to be obtained from human remains, even if no tooth or bone samples are available.
Research was conducted by Alejandra perotti, an Associate Professor of Invertebrate Biology from the University of Reading.
He stated that he had seen the movie Jurassic Park’s mosquito story, where they were encased with amber and carried the DNA of their dinosaur hosts. However, he said, “Like those insects, ours can also be kept safe by sticky headlice.”
Dr Perotti stated that lice biology could provide useful clues to the history of people’s lives thousands of year ago.
“The demand for ancient human DNA has increased in recent years, as we attempt to better understand the migration patterns and differences in human societies.
The ancestors of human beings have been accompanied by their heads for all time. The new way to preserve unique specimens and learn more about them could be a great resource.
Because these samples are of the highest quality, most ancient DNA can be extracted from bone in the skull and inside the teeth.
However, it’s not possible to obtain skull or teeth remains from all cultures. It can also be considered unethical and against cultural beliefs for samples taken from the early Indian remains.
These extractions are not allowed due to severe damage or destructive sampling.
It is possible to retrieve DNA from lice cement.
The DNA taken from the mummies in Argentina revealed they reached the Andes mountains of the San Juan province, Central West Argentina.
The DNA of the “cement” head lice that used glue to attach their eggs to the hairs of mummified South American bodies thousands years ago was extracted by a team.
The team also studied ancient nits on human hair used in a textile from Chile and nits from a shrunken head originating from the ancient Jivaroan people of Amazonian Ecuador.
The samples used for DNA studies of nit cement were found to contain the same concentration of DNA as a tooth, double that of bone remains, and four times that recovered from blood inside far more recent lice specimens.
Dr Winther Pedersen said: ‘The high amount of DNA yield from these nit cements really came as a surprise to us and it was striking to me that such small amounts could still give us all this information about who these people were, and how the lice related to other lice species but also giving us hints to possible viral diseases.
‘There is a hunt out for alternative sources of ancient human DNA and nit cement might be one of those alternatives. I believe that future studies are needed before we really unravel this potential.’
As well as the DNA analysis, scientists were also able to draw conclusions about a person and the conditions in which they lived from the position of the nits on their hair and from the length of the cement tubes.
They were able to determine the sex of the human hosts, how the populations migrated throughout south America, and evidence of viruses.
The DNA extracted from the cement was of better quality than that recovered through other methods, according to the team led by the University of Reading
The team revealed a genetic link between three of the mummies and other humans known to be living in Amazonia 2,000 years ago.
‘This shows for the first time that the original population of the San Juan province migrated from the land and rainforests of the Amazon in the North of the continent, in the area south of current Venezuela and Colombia,’ the authors found.
They also discovered that all ancient human remains studied belonged to the founding mitochondrial lineages in South America.
The mummies were all likely exposed to extremely cold temperatures when they died, which could have been a factor in their deaths.
This was indicated by the very small gap between the nits and scalp on the hairs shaft. Lice depend on their host’s heat for warmth and will lay eggs in cold areas closer to the scalp.
Due to cement degradation over time, shorter cement tubes are associated with hairs that have been preserved longer.
In addition to the University of Reading researchers were also from Bangor University (Wales), the Oxford University Museum of Natural History and the University of Copenhagen (Denmark).
These results were published in the Journal of Molecular Biology and Evolution.