There is a grave near the Swedish town of Birka that was the final resting place of a Viking warrior. The grave, called Bj 581, was filled with weapons, including a sword, battle knife, axe, armor-piercing arrows, a spear and two shields as well as a full set of gaming pieces with a board, and the skeletons of two horses—a mare and a stallion. First described in the late 1800s, this grave has been held up as the example of what a Viking warrior burial site would look like because it was so well furnished.
Isolating and sequencing DNA from ancient samples is a highly specialized field of research that easily captures the imagination. For me it started in the early 90’s when I read about researchers using PCR (a relatively new technique at the time) to amplify, and subsequently sequence, the mitochondrial DNA of an extinct subspecies of zebra using a sample collected from a skin rug found at an estate in England.
From samples a few hundred years old to ones that are thousands of years old, scientists have made good use of technological advances to push back the boundaries of time. In this video from Science, Evolutionary Biologist Beth Shapiro talks about working with ancient DNA, and how new advances such as Next Generation Sequencing have made it possible to gather more information from ancient samples.
Science put together a Special Issue focused entirely on the research surrounding ancient DNA. You can find all the articles in this Special Issue here:
Smallpox was a disease caused by infection with one of two strains of Variola virus (Variola major and Variola minor) and a worldwide scourge that killed up 35% of the people it infected. Luckily, a vaccine was developed when Edward Jenner noticed milkmaids infected with cowpox did not contract smallpox. While Jenner was not the first to vaccinate against smallpox, his discovery and testing were spread to a wide audience and thus became the basis for the vaccination efforts that have eradicated the virus in our lifetime. Despite all the research on smallpox, not much is known about the evolution of the virus. Sequence data for the virus only span the last 50–60 years. However, recent efforts published in the New England Journal of Medicine uncovered a new source for examining the history of smallpox infection: mummies. Continue reading
In central England, an archaeological dig is happening in an unlikely spot—a parking lot in the city of Leicester. The goal: To find the final resting spot of Richard III, the last of England’s Plantagenet kings and perhaps one of its most maligned rulers. Richard III reigned over England for only two years before being killed by Henry Tudor’s army during the Battle of Bosworth Field in August 1485 at the end of the War of the Roses, which pitted Richard’s House of York against the House of Lancaster. Many historical records suggest that Richard’s body was brought to Leicester and buried between the nave and altar at Grey Friars church. You would think that a king’s tomb would be well marked and well remembered, even for an unpopular king like Richard III, but that is not the case here. Henry was said to have erected a memorial for his former rival, but that and any other monuments, along with the church itself, are long gone, destroyed during the Dissolution of the Monasteries, when Henry VIII was named Supreme Head of the Church in England and systematically razed monasteries, convents and friaries throughout England, Wales and Ireland between 1536 and 1541. Since then, the exact location of Richard III’s remains was lost to history. However, thanks to a team of University of Leicester archaeologists and geneticists that might be changing.
Archaeologists have made an interesting discovery while excavating the late Bronze Age/early Iron Age settlement named Cladh Hallan on the island of South Uist in the Outer Hebrides, Scotland. They have uncovered four human skeletons buried at regular intervals beneath three roundhouses dating from the 11th century BC: an adult male, an adult female, a 10–14-year-old girl and a 3-year-old child. The careful arrangement of these burials directly below the roundhouses led archaeologists to initially hypothesize that these might be foundation burials—an ancient practice in which people, usually younger people, were sacrificed and buried under a building’s foundation in the belief that their blood and spirit would protect and strengthen the building and building site. As strange as that custom seems to us, it gets weirder. Two of these skeletons showed signs of mummification and contained skeletal elements from multiple individuals intentionally pieced together to form intact skeletons. Continue reading
The pharaoh Tutankhamun ruled ancient Egypt during the 18th dynasty of the New Kingdom (circa 1550–1295 BC), one of the most powerful royal houses in ancient Egypt. Although he sat on the throne for only 9 years and died at the young age of 19, he is one of the most well known pharaohs, due largely in part to the discovery of his intact tomb by archaeologist Howard Carter in 1922. The tomb was filled with riches befitting a king, including an elaborate sarcophagus with a gold burial mask and statues of ancient Egyptian gods such as Osiris and Anubis, as well as gold jewelry, statues and images of servants, ornate furniture, models of boats and other items that the pharaoh would need in the afterlife. A lesser known item discovered in his tomb was an undecorated wooden box in which two small gilded coffins lay side by side. These coffins held the mummified remains of King Tutankhamun’s two stillborn daughters. Recently, researchers examined these remains in detail to determine their gestational ages and characterize any congenital abnormalities that they might have inherited from the boy king.
After writing my review of the Proceedings of the National Academy of Sciences USA article “Targeted enrichment of ancient pathogens yielding the pPCP1 plasmid of Yersinia pestis from victims of the Black Death”, I vaguely wondered if the authors could have sequenced more than a single 10kb plasmid. If the single-copy chromosomal DNA was too scarce, maybe one of the other Yersina pestis plasmids that may exist at a higher copy number (e.g., pMT1) might be sequenced. Continue reading
Last year, I reviewed a PLoS Pathogens paper that found European Black Plague victims from the mid 14th century were infected with more than one clone of Yersinia pestis. While the Y. pestis-specific sequences amplified from several skeletal samples from various countries were evidence of the bacterium as the etiological agent, questions still remained about the virulence of the outbreak. What allowed that ancient strain of Y. pestis to cause such widespread death? Another group of researchers decided to further analyze the causative agent of the Black Plague by enriching for and sequencing one of the extrachromasomal plasmids present in the bacterial genome: the 9.6kb virulence-associated pPCP1 plasmid. Continue reading