Researchers sequenced DNA from modern Indigenous groups in the Americas, including the Quechua, who live in the Andes. (Image credit: Dan Kitwood/Getty Images) Humans migrated to South America in three distinct waves over the course of thousands of years, a new large-scale analysis of Indigenous Americans' DNA reveals. The investigation also found that genes related to fertility, metabolism and the immune response helped people adapt to their unique environment in the "final frontier" of human migration, the researchers said. In a study published Wednesday (April 22) in the journal Nature , an international team of scientists detailed findings from the Indigenous American Genomic Diversity Project, which analyzed 128 genomes from people living in Argentina, Bolivia, Brazil, Colombia, Ecuador, Mexico, Paraguay and Peru — an investigation that included 45 populations and 28 language families.…