Findings from a new study have suggested that a pair of Egyptian "sister mummies" that were entombed side by side after they died about 4,000 years ago may have been half brothers and not full brothers.
The bodies were discovered by a team led by British archaeologist Flinders Petrie in the village of Deir Rifeh south of Cairo in 1907. It was believed that mummies were nobles who died around 1800 BC. Nakht-Ankh is older for at least 20 years, but the young Khnum-Nakht died six months earlier.
In 1908, archaeologist Margaret Murray discovered that the skeletal morphology of bodies was not the same, suggesting the absence of family relationship. Some thought that one of the brothers was adopted, although there was no scientific evidence to prove this. DNA analyzes now show that they only shared a mother, not a father, confirming previous suspicions.
In a study published in the February issue of Journal of Archaeological Science: Reports the researchers performed DNA analysis, which confirmed that the Khnum-Nakht and Nakht-Ankh brothers have different paternal lines.
The researchers extracted the DNA from the molars of the two mummies and then analyzed their mitochondrial DNA, the genetic material transmitted by their mother and the Y chromosome DNA, which is transmitted from their father.
The findings revealed that the two mummies belong to the mitochondrial haplotype M1a1, which shows a maternal relationship.
"The two mummies had identical mitochondrial profiles, [so] we can be sure they were related by the mother," said study researcher Konstantina Drosou of the Manchester Institute of Biotechnology.
The analysis of the sequences of the Y chromosome, however, showed variations, which means that Nakht-Ankh and Khnum-Nakht had different paternal lineage.
"The sequences of the Y chromosome were less complete but showed variations between the two mummies, indicating that Nakht-Ankh and Khnum-Nakht had different fathers," researchers wrote in their study.
"Our study emphasizes the importance of kinship in ancient Egypt and represents the first successful typing of mitochondrial DNA and Y chromosome in Egyptian mummies."
It is not clear if one of the brothers was adopted or if his mother, Khnum-Aa, had an affair. However, the study solved one of the mysteries surrounding two of Britain's most famous Egyptian mummies.
"I am very grateful to have been able to add a small but very important piece to the great puzzle of the story and I am sure the brothers would be very proud of us. These moments are what make us believe in ancient DNA," said Drosou .