Ancient Egyptian man's genome reveals his society's cross-cultural ties
By Will Dunham
(Reuters) -DNA obtained from the remains of a man who lived in ancient Egypt around the time the first pyramids were built is providing evidence of the ties between two great cultures of the period, with a fifth of his genetic ancestry traced to Mesopotamia.
Although based on a single genome, the findings offer unique insight into the genetic history of ancient Egyptians - a difficult task considering that Egypt's hot climate is not conducive to DNA preservation.
The researchers extracted DNA from the roots of two teeth, part of the man's skeletal remains that had been interred for millennia inside a large sealed ceramic vessel within a rock-cut tomb. They then managed to sequence his whole genome, a first for any person who lived in ancient Egypt.
The man lived roughly 4,500-4,800 years ago, the researchers said, around the beginning of a period of prosperity and stability called the Old Kingdom, known for the construction of immense pyramids as monumental pharaonic tombs.
The ceramic vessel was excavated in 1902 at a site called Nuwayrat near the village of Beni Hassan, approximately 170 miles (270 km) south of Cairo. The researchers said the man was about 60 years old when he died, and that aspects of his skeletal remains hinted at the possibility that he had worked as a potter.
The DNA showed that the man descended mostly from local populations, with about 80% of his ancestry traced to Egypt or adjacent parts of North Africa. But about 20% of his ancestry was traced to a region of the ancient Near East called the Fertile Crescent that included Mesopotamia.
"This suggests substantial genetic connections between ancient Egypt and the eastern Fertile Crescent," said population geneticist Adeline Morez Jacobs of Liverpool John Moores University in England and the Francis Crick Institute in London, lead author of the study published on Wednesday in the journal Nature.
The findings build on the archaeological evidence of trade and cultural exchanges between ancient Egypt and Mesopotamia, a region spanning modern-day Iraq and parts of Iran and Syria.
During the third millennium BC, Egypt and Mesopotamia were at the vanguard of human civilization, with achievements in writing, architecture, art, religion and technology.
Egypt showed cultural connections with Mesopotamia, based on some shared artistic motifs, architecture and imports like lapis lazuli, the blue semiprecious stone, the researchers said.
The pottery wheel from Mesopotamia first appeared in Egypt at about the time the man lived, a period when the earliest pyramids began to spring up near modern-day Cairo, starting with the Step Pyramid of the pharaoh Djoser at Saqqara and later the Great Pyramid of the pharaoh Khufu at Giza.
About 90% of the man's skeleton was preserved. He stood about 5-foot-3 (1.59 meters) tall, with a slender build. He also had conditions consistent with older age such as osteoporosis and osteoarthritis, as well as a large unhealed abscess from tooth infection.
"Ancient DNA recovery from Egyptian remains has been exceptionally challenging due to Egypt's hot climate that accelerates DNA degradation, with high temperatures breaking down genetic material over time compared to cooler, more stable environments," Francis Crick Institute population geneticist and study co-author Pontus Skoglund said.
"In this case, the individual's burial in a ceramic pot vessel within a rock-cut tomb likely contributed to the unusual DNA preservation for the region," Skoglund added.
The fact that his burial occurred before mummification became standard practice in Egypt may have helped avoid DNA degradation because his remains were spared elaborate preservation techniques.
Scientists have struggled to recover ancient Egyptian genomes, according to paleogeneticist and study co-author Linus Girdland Flink of the University of Aberdeen in Scotland. One previous effort yielded partial genome sequencing of three individuals who lived some 1,500 years after the Nuwayrat man.
Given the track record, the researchers were surprised with their success in sequencing the man's genome.
"Yeah, it was a long shot," Skoglund said.
The man may have worked as a potter or in a trade with similar movements because his bones had muscle markings from sitting for long periods with outstretched limbs.
"All indicators are consistent with movements and positions of a potter, as indicated in ancient Egyptian imagery," said bioarcheologist and study co-author Joel Irish. "He would have been of high status to have been buried in a rock-cut tomb. This conflicts with his hard physical life and conjecture that he was a potter, which would ordinarily have been working class. Perhaps he was an excellent potter."
(Reporting by Will Dunham in Washington, Editing by Rosalba O'Brien)
