UC San Diego

South American populations have a complex admixture history. The earliest Native Americans are known to have migrated into the Americas as early as 14000 years ago. The region saw large scale migrations from European colonial powers starting early 1500s. In just a couple of centuries the entire Western hemisphere came under the control of these European powers. These colonial powers brought millions of Africans across the Atlantic between the 1500s and 1800s through the slave trade which led to further admixture of African populations into the Americans. Due to multiple migrations events, presence of different colonial powers that followed different slave trade practices, South Americans populations have a highly heterogeneous genetic composition. We investigate the admixture history of one of the South American populations living in Cerro de Pasco, a high altitude mining town in the Andes region of Peru. Studying the admixture history of this population can give us important insights into the origins of several selection forces at play in this population. We found the Andean population to have lesser proportions of European and African ancestry as compared to the other South American populations. The timing of European and African admixture into this population was also found to be significantly different from other populations, which could be a direct result of lower European and African ancestry proportion. These results indicate a higher level of segregation between the Native Americans and the European/African populations in Peru as compared to other regions.