Early TB Variants Traveled Long Distances on Land in Ancient DNA

Early TB Variants Traveled Long Distances on Land in Ancient DNA ...

Tuberculosis is the second most common cause of death worldwide by an infectious pathogen, COVID-19 being the first. However, many aspects of TBs long history are still controversial. This complex evolutionary puzzle is now evidenced that non only does TB pre-date the arrival of European settlers in the Americas, but early TB variants also traveled long distances on land.

Using the findings from 2014, a recent study found that TB would be attributed to marine mammals like seals and sea lions, which found cases in people who lived nowhere near the coast, suggesting that these infections were not caused by direct transmission from seals, but rather caused by one or more spillover events.

Three new ancient TB genomes have been discovered by a research assistant professor of anthropology at the University of Oklahoma, as well as Ashild Vagene, the Section for Evolutionary Genomics at the University of Copenhagen.

These three new cases of pre-contact-era South American TB are from human remains that are situated on the Colombian Andes'' highlands. All of these three new three TB genomes are identical to those discovered in ancient coastal Peruvian individuals, as well as in modern-day seals and sea lions.

The researchers, which includes scientists from the Max Planck Institute for Evolutionary Anthropology and Arizona State University, used archaeological evidence and stable isotope statistics to prove that the inland individuals did not have contact with marine mammals. Thus, the TB transmission was most likely from the bacterium jumping to other species.

The TB bacterium is capable of infecting many mammalian mammals, and it has many applications for it''s terrestrial dispersal, including humans.

Colombia''s terrestrial mammals have been populated by people''s animal life, according to Honap. Or, in a more probable scenario, it might have been brought inland via human-to-human transmission, facilitated by trade routes!

Anne Stone, one of the researchers'' contributors and a specialist in the evolution of TB, believes these findings provide an opportunity for further exploration into the history of the disease in the Americas before the colonial period.

It''s a great time in ancient DNA research, as we can now look at genome-level differences in these ancient pathogens and track their movements across different continents and beyond, according to an expert.

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