For Those Interested in Archaeology

"The first people to step foot in the Americas were harboring a sliver of DNA from two extinct Eurasian human groups: the Neanderthals and the Denisovans, a new study finds. This genetic relic could have helped the earliest Americans fight diseases they encountered in their new environment, the researchers proposed.
Everyone alive today is "a result of like three different species coming together," study co-author Fernando Villanea, a population geneticist at the University of Colorado Boulder, told Live Science.
"What we think has happened is that humans had this archaic variation," study co-author Emilia Huerta-Sanchez, a population geneticist at Brown University, told Live Science. As people expanded into the Americas, they did not have to wait to develop new mutations to fight off new pathogens and could instead draw from the arsenal of genetic variants they gained from other human groups, she said.
In the new study, published Thursday (Aug. 21) in the journal Science, the researchers detailed their analysis of MUC19, a protein-coding gene with various functions, including coding for the consistency of mucus. They found that 1 in 3 Mexicans alive today has an MUC19 gene similar to that of Denisovans, a mysterious group of ancient humans who lived throughout Asia from about 200,000 to 30,000 years ago."
The first Americans had Denisovan DNA. And it may have helped them survive.