Science Continues to Prove Up History By Using New Genomic Tools
Some parts of history increasingly involve science. Last month there was news of "museumomics" – using DNA from museum samples to look back in time by obtaining and analyzing old DNA from museum samples of Tasmanian Devils, an animal now facing a vicious cancer spread by a virus. Now there is news from ScienceDaily of scientists finding and analyzing remnants of 600 year old human teeth in order to find and prove the pathogen responsible for "the Black Death."
The full article is available here through the genius of freely available scientific information provided by the Proceedings of the National Academies of Science. Here are key excerpts from the ScienceDaily summary:
"Previous genetic tests indicating that the bacterium was present in medieval samples had previously been dismissed as contaminated by modern DNA or the DNA of bacteria in the soil. Above all, there was doubt because the modern plague pathogen spreads much more slowly and is less deadly than the medieval plague — even allowing for modern medicine.
The international team of researchers has for the first time been able to decode a circular genome important for explaining the virulence of Y. pestis. It is called pPCP1 plasmid and comprises about 10,000 positions in the bacterium’s DNA. The sample was taken from skeletons from a London plague cemetery. The working group in Tübingen, led by Dr. Johannes Krause used a new technique of "molecular fishing" — enriching plague DNA fragments from tooth enamel and sequencing them using the latest technology. In this way, the fragments were connected up into a long genome sequence — which turned out to be identical to modern-day plague pathogens. "That indicates that at least this part of the genetic information has barely changed in the past 600 years," says Krause.
The researchers were also able to show that the plague DNA from the London cemetery was indeed medieval. To do that, they examined damage to the DNA which only occurs in old DNA — therefore excluding the possibility of modern contamination. "Without a doubt, the plague pathogen known today as Y. pestiswas also the cause of the plague in the Middle Ages," says Krause, who is well known for his DNA sequencing of ancient hominin finds, which help trace relationships between types of prehistoric man and modern humans."