A group of scientists specializing in genetics in a US laboratory has reconstructed in detail the faces of three ancient Egyptian mummies from a community on the banks of the Nile from DNA sequencing more than 2,000 years ago. The authors of the analysis believe this is the first time that advanced techniques have been used to predict an individual's observable traits, phenotypic traits – in this physical case – with such ancient human DNA.
The mummies' faces, matching those of three men, were reconstructed with an appearance of about 25 years old, based on the assumption that their skin was light brown, and their eyes and hair were dark and freckle-free. In addition, the analysis of their DNA also made it possible to predict that the three individuals are of Jewish ancestry and have roots from Yemen, Morocco and Tunisia, respectively. The study submitted by Parabon nanolabs, which specializes in DNA phenotyping services, at an international conference in the field this month in Florida.
"We were all surprised and amazed to see that DNA no longer resembled modern Egyptians," explains Eileen McCray, director of bioinformatics at Parabon NanoLabs. "And that, of the three faces, only one was Egyptian, and the others were southern European to me, and this is in fact what we also see in the ancestry: that these people were, genetically, more similar to the people of my own than to the people of the present in Egypt ".
The mummies whose DNA was used came from an archaeological site that touched the Nile called Abu Sir al-Maleq, located in central Egypt and inhabited from at least 3250 BC until about 700 of the same era. The individuals in question lived at various times from the late New Kingdom to Roman times in ancient Egypt, and were baptized using alphanumeric symbols: JK2134, the oldest, dates from between 776 and 569 BC, and JK2911 lived between 769 and 560 at the same time, It is estimated that JK2888 did this around the years 97 and 2.
The results of the analysis, which indicate that the ancestors of the three individuals were not from sub-Saharan Africa, are consistent with previous studies that determined that the ancient Egyptians shared more ancestry with Middle Eastern populations than with modern Egyptians. Additional mixing of the sub-Saharan in recent times, according to the report.
"If you compare these individuals genetically to modern populations, their DNA was more similar to the DNA of individuals from Yemen, Tunisia, and Morocco, and not so much to the people living in Egypt today," McCray says. "They could have come from other parts of the Mediterranean, and show no African ancestry, whereas modern Egyptians do," he notes.
"If we could do this with DNA from 2,000 years ago, then surely we can do it with DNA from 50 years ago."
Primary data for the mummies were obtained from European Nucleotide Archive (ENA), an open repository that provides free access to DNA data. From there, McCray explains that Parabon has a database of thousands of individuals with information about their DNA and shape. Thus, when they have a DNA sample from someone they don't know, as was the case with mummies, they use predictive models developed from the database to be able to determine their facial features. They were then compared with each other to discover and emphasized differences and combined with pigmentation prediction so that the forensic artist could create the structures that were shown.
McRae points out that the main challenge with this process was that the individuals' DNA was very old and, therefore, damaged by exposure in the environment for thousands of years, even after bacteria were removed, from the sequence data still missing. To guess the missing pieces of the puzzle, the group had a very advanced tool, called Low Coverage Inclusion, that allows them to identify them statistically from the pieces around them. "With the data coming in, we weren't able to do that analysis," McCray says.
"This really shows how powerful these techniques are in challenging samples," he says. "[Porque] If we can do it with DNA that goes back 2,000 years, then of course we can do it with DNA that goes back 50 years."
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