Scientists have unravelled part of the genetic code of a child who was sacrificed in a ritual ceremony by the Inca civilisation 500 years ago. The boy's mummified remains were discovered on an Argentinean mountain. Analysis of his mitochondrial DNA, which is passed from mother to child, showed that the boy's closest living relatives are in Peru and Bolivia.
He belonged to a population of native South Americans that almost disappeared after the Spanish conquest. Researchers in Spain were given permission to extract mitochondrial DNA from the seven-year-old boy to study part of his genome. By comparing his genetic code with hundreds of thousands of samples held in genetic databases, they found his genetic profile was very rare.
One match was to DNA from an individual belonging to the ancient Wari Empire, which ruled the Andes long before the Incas. And three were to modern-day people living in Peru and Bolivia.
Lead researcher Antonio Salas, a geneticist at the University of Santiago de Compostela, said the data suggested that the boy's genetic line is nearly extinct in modern-day people but was probably more common at the time of the Incas.
"It is well-known that the effective population size was severely reduced at the arrival of the Spanish conquerors (due, for example, to epidemics caused by pathogens brought by Europeans, such as influenza)," he said.