Scientists from the University of Illinois recently conducted a study using whole exome sequencing to explore the DNA of 25 deceased individuals of the Tsimshian people that range from 500 to 6000 years old. These scientists were looking to compare the immune system-related genes of these ancient humans to modern humans.
The scientists found that in the ancient DNA, 100% of individuals has a gene variant called HLA-DQA1. This gene helps the immune system decide which cells are healthy and which are infected with a pathogen. In the DNA of some of the more modern Tsimshian deceased, the gene variant was only found in 36% of individuals. This finding leads the scientists to believe that the disruptive effect of European's introduction of new pathogens like smallpox and measles viruses to the Americas may have had a significant impact on First Nations genetics.
Photo and Story by Science. http://www.sciencemag.org/news/2016/11/european-diseases-left-genetic-mark-native-americans