Mummies are useful for lots of things: Halloween costumes, Scooby-Doo episodes, ancient Egyptian crafts, and you can get a lot of mileage out of mummy puns, if you're into that sort of thing. But an international team of researchers has just discovered they're also good for parsing the origins of ancient Egyptians themselves.
Scientists have long assumed mummies were a dead end as a source of DNA helpful for studying ancient human populations. Over the years, researchers have tried different methods of extracting genetic material from mummified remains, but Egypt's hot climate, the humidity of the tombs in which the mummies were buried, and the chemicals used in the mummification process have, up until now, rendered their DNA unreadable.
Looking Back Through Time
A new study, though, published in the journal Nature Communications shows that sequencing DNA from mummies is possible — it just takes an international team of ancient DNA specialists and some futuristic sequencing techniques to figure out how.
So, what do you do with reliable mummy DNA data? You figure out what the deal is with the ancient Egyptians, of course.
Ancient Egypt's political history was incredibly long and turbulent — all its neighbors had a go at the empire at some point: Assyrians, Nubians, Persians, Greeks and Romans, just to name a few.
"We wanted to test if the conquest of Alexander the Great and other foreign powers has left a genetic imprint on the ancient Egyptian population," said co-author Verena Schuenemann of the University of Tuebingen, in a press release.
The researchers sampled 151 mummies dating from between 1388 B.C.E. and 426 C.E., excavated in the 20th century from an archaeological site along the Nile in middle Egypt called Abusir el-Meleq. The team obtained mitochondrial DNA (which tells the story of the DNA that's passed down from the mother, but reveals nothing about the father) from 90 mummies, and retrieved completely intact genomes from three.
This data revealed some insights into what ancient Egyptians were like. First, the genomes didn't change much over the 1,300-year span of history represented in these mummies, and that's despite the constant invasions. Second, when the researchers compared the DNA of the three intact mummy genomes to those of modern people from the same region of Egypt, they found these ancient Egyptians were genetically more closely related to people of the Near East — present-day Syria, Lebanon, Israel and Palestine — than they were to contemporary Egyptians.
These days, about 20 percent of the DNA of modern Egyptian populations can be traced to sub-Saharan African origins, whereas ancient Egyptians had none. In fact, the data suggest modern Egyptians share about 8 percent more ancestry with sub-Saharan Africans than with ancient Egyptians.
"This suggests that an increase in sub-Saharan African gene flow into Egypt occurred within the last 1,500 years," said co-author Stephan Schiffels, of the Max Planck Institute for the Science of Human History.
This is possibly due to more recent long-distance trade between sub-Saharan Africa and Egypt on the Nile, and to the trans-Saharan slave trade that started around 1,300 years ago.
And in addition to revealing information about human migration, the new findings also underscore that as far as Egyptian mummies go, much more remains to learn from remains.