The team found that modern Mexicans have the highest frequency of Denisovan-specific MUC19 variants, with about 33% of the population carrying this version of the gene. About 20% of Peruvians carry the variant, while only about 1% of Colombians and Puerto Ricans do. The researchers believe this is due to the fact that Mexicans have, on average, more Native American DNA in their genomes than other populations.