Overview

• Published in Science, the study compared 1000 Genomes data from Mexico, Peru, Colombia and Puerto Rico with sequences from 23 ancient Indigenous Americans plus three Neanderthals and one Denisovan.
• Roughly 33% of Mexicans carry the Denisovan-like MUC19 haplotype, about 20% of Peruvians do, and around 1% of Colombians and Puerto Ricans do.
• The MUC19 segment in modern humans contains a Denisovan core flanked by Neanderthal DNA, indicating transmission from Denisovans to Neanderthals before entering Homo sapiens.
• The Denisovan-derived haplotype is present at high frequency in ancient remains across North and South America, showing persistence since early settlement.
• Statistical tests detect an unusually long archaic tract and allele frequency patterns consistent with positive selection, while MUC19’s specific immune effects remain to be determined.