Mitochondrial DNA analysis of ancient Peruvian highlanders

Area of Science:

• Paleogenetics
• Archaeogenetics
• Ancient DNA Analysis

Background:

• The Inca Empire integrated diverse populations, leading to questions about the origins of people living near major sites like Machu Picchu.
• Previous osteological studies suggested Machu Picchu's inhabitants were a mix of coastal and highland peoples.
• Understanding the genetic landscape of communities supporting Inca sites is crucial for reconstructing regional history.

Purpose of the Study:

• To determine the indigenous origins of ancient individuals from Paucarcancha and Patallacta.
• To test the hypothesis of highland origins for these communities based on genetic data.
• To compare ancient DNA with modern Central Andean populations.

Main Methods:

• Ancient DNA extraction from 57 individuals excavated near Machu Picchu.
• Polymerase chain reaction (PCR) amplification and sequencing of mitochondrial DNA (mtDNA) control and coding regions from 35 individuals.
• Haplogroup determination and frequency analysis.

Main Results:

• Mitochondrial DNA haplogroup frequencies showed clear genetic proximity to modern Quechua and Aymara populations.
• The genetic profile contrasted with pre-Hispanic individuals from the north coast of Peru.
• A strong genetic affinity was found between the sampled late pre-Hispanic individuals and modern Andean highlanders.

Conclusions:

• The sampled individuals from Paucarcancha and Patallacta were indigenous highlanders.
• These highlanders likely provided support for the nearby Inca royal estate and ritual site of Machu Picchu.
• The findings support a model of highland populations contributing to the infrastructure and support systems of major Inca centers.