Genetics: A rare Inca child mummy genome

The mitochondrial genome (mitogenome) of an Inca child mummy from approximately 500 years ago is presented in Scientific Reports this week. The results suggest that the child belonged to a genetic population who shares a common ancestor (haplogroup) which has previously not been identified in modern Native Americans. This group is thought to be a branch off from the root of haplogroup C1b.

In the summer of 1985 a frozen mummy was found at the south western edge of the Aconcagua Mountain at the base of the Piramide Mountain in the Argentinean province of Mendoza. Archaeological and anthropological studies identified the mummy as a seven-year-old boy, who had been the victim of an Inca sacrifice ritual known as "capacocha", approximately 500 years ago.

Antonio Salas and colleagues extracted and sequenced the entire mitochondrial DNA genome from the lung of the mummy. Through comparison with a worldwide database of approximately 28,000 mitogenomes, the authors identified that the Inca mummy belonged to a haplogroup called C1bi that had not been identified previously. Using a database of haplotypes (DNA variations that tend to be inherited together) the authors found there may be members of the C1bi haplogroup living in Peru and Bolivia today. They also identified an individual from the ancient Wari Empire who belonged to this group. The authors suggest that the mummy represents a rare genetic sub-clade of human maternal ancestors that arose approximately 14, 300 years ago in Peru, which is consistent with archaeological findings.