The standard Viking funeral involved being burned in a pyre at sea. But luckily for scientists, a few marauding Norsemen were left behind, buried in the ground. Now their skeletons can be examined in detail, and might even show us what human DNA looked like a millennium ago.
A team of scientists led by Jørgen Dissing at the University of Copenhagen have extracted authentic Viking DNA from teeth that were still sitting in the jaws of the thousand-year-old corpses. The DNA samples came from a burial site on the Danish island of Funen which dates from A.D. 700 to 1000.
Of course, you can’t just waltz into a boneyard, grab a tooth, and expect it to be authentic. Experts regard samples of ancient human DNA with upfront suspicion. Modern humans can easily contaminate the samples with our own DNA just by handling them—our DNA mixes in with the ancient genetic material and creates an intractable mess, Dissing says. Scientists don’t know for sure how it happens, but teeth in particular are most susceptible to contamination just as they’re being unearthed for the first time.
So Dissing and his team set out to prove that they could achieve a pure DNA sample. They forbade archaeologists or anyone else from laying a finger on the skeletons at any time, and the team donned protective suits for the excavation process and removed the last bit of earth themselves. Then they squired the teeth to ultra-clean labs for study.
The DNA test results found that the samples from Galgedil, the burial ground, contain gene sequences that have rarely been found in modern Scandinavians. But for this study, the method is the message—scientists could use Dissing’s ultra-cautious approach to better preserve ancient DNA. Vikings may have been brutish invaders, but at least in death they might have given the world something good—evidence that we can study DNA from our long-dead ancestors, provided we’re incredibly careful.