Trending Science: Mummy DNA unlocks the genetic mysteries of the Ancient Egyptians

Ancient Egypt has long held an almost mystical allure over schoolchildren of all ages (and quite a few adults). With pyramids, canoptic jars, hieroglyphics, cursed tombs and of course, mummies, it was a civilisation that offered all of the ingredients for us moderns to let our imaginations run wild. However, archaeologists and scientists have been exasperated for decades about one thing ancient Egypt hasn’t gladly offered up for us: Its DNA.

This has now all changed, as a team of scientists led by Johannes Krause at the Max Planck Institute for the Science of Human History in Jena, Germany, has used next-generation sequencing methods to analyse DNA from 151 mummy heads spanning different periods in ancient Egypt. Because of the Ancient Egyptian Empire’s often tumultuous history, being conquered at various points by Assyrians, Nubians, Persians, Greeks and Romans (amongst others), the team were interested to discover whether the frequent conquests by external powers left a lasting genetic impact.

The 151 mummies came from the ancient settlement of Abusir el-Meleq, about 100 kilometres from Cairo. In ancient times, the settlement was devoted to Osiris, the ancient Egyptian god of the dead, and as such was a popular burial ground for many centuries. The heads were excavated and removed from their bodies in the early 20th century and are now kept as part of two collections, both in Germany. Radiocarbon dating showed that the mummies spanned over 1 300 years of ancient Egyptian history.

The mummies’ soft tissue contained almost no DNA (and this is the reason why scientists have previously believed it was impossible to extract DNA from mummies), but the bones and teeth were teeming with it. 90 of the mummies had incomplete DNA and only three retained complete genomes. These three were the ones that Krause’s team focused on.

They then compared the mummy DNA to the DNA of ancient and modern peoples in the region. They discovered that on a genetic level, the ancient Egyptians were not so different from modern people living in the Near East, having more in common with people from the Levant (modern Lebanon, Israel and Syria) than with modern Egyptians. Overall, the constant conquest of their lands by foreign powers had very little impact on the genetic make-up of the ancient Egyptians, which was a surprise for the research team.

Another unexpected discovery was that 20 % of present-day Egyptians have genes originating from sub-Saharan Africa, whilst none of the mummies studied had sub-Saharan genes. In essence, modern Egyptians have become much more ‘African’ in recent centuries. ‘It’s really unexpected that we see this very late shift,’ commented Krause. He suspects that increased trade along the Nile, including the Slave Trade, and the spread of Islam in the Middle Ages intensified contact between Northern and sub-Saharan Africa.

The DNA sequencing method employed by Krause’s team ensures the robustness of their findings. The team looked at any DNA in a given sample and then isolated the genetic material that might be human. The team then looked for patterns of DNA damage that is only seen in truly ancient DNA, which allowed them to simply ignore the DNA that might be the result of contamination.

Whilst these findings are indeed impressive, other geneticists, such as Iosif Lazaridis at Harvard Medical School, have wondered whether that mummies from other regions of Egypt might reveal differing genetic stories. At its zenith during the New Kingdom Period, the Egyptian Empire stretched far into the Levant and south along the Nile in what is now Sudan. Other populations in the empire may have experienced conquests differently from those mummies buried at Abusir el-Meleq, including the possibility of more intense genetic mixing.

However, that is for a future study, because now that Krause and his team have proven that it’s possible, there are now thousands of mummies in museums and collections across the world that are now waiting to have their DNA examined more closely by eager scientists!