Our project will focus on tracking the genetic, epigenetic, and microbiota changes experienced by the Sakha people (Yakuts) in Far Eastern Siberia, following contact with Russians from 1632. Prior to Russian contact, native Yakuts had never been exposed to germs such as smallpox and tuberculosis. The arrival of Russians in the region resulted in massive epidemiological outbreaks, which decimated the population. Likewise, the Yakut traditional diet was also transformed to include more carbohydrates, derived from the newly introduced cereals and potatoes. Therefore, Russian contact kick-started, as early as the 17th century, a series of deep transformations in the Yakut society, which continued in the following centuries with the rise of the Soviet Union in the early 1900s and the emergence of antibiotics after 1950. Our project associate: (i) The excavation of frozen grave from periods and/or sites which has never been excavated before and that we expect that they will furnish unexpected results about the history of population of this part of the world. (ii) The study of biological modifications experienced by human groups following population contact and change in lifestyle at three levels, genomic, epigenetic and microbial level. The samples that will be studied include the human sample excavated from 2002 to 2015 and the new ones that we excavate and which are susceptibility to change the history of the population of this part of the world and of the arctic.