In the last decade, the number of both ancient and present-day genomes sequenced has exploded, leading to new discoveries each year on the genetic history of different species. The work in my lab has two major components. The first is the application of computational population genetic tools to the study of the evolutionary history of many organisms, particularly our own species, H. sapiens. My postdoctoral work at the Molecular Paleontology Lab in the Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China focused on determining the genetic history of ancient humans in East Asia, including their relationship to present-day human populations. The second is the assessment and development of computational tools to determine and infer demographic relationships, especially with the inclusion of ancient DNA. My graduate work in the Department of Integrative Biology at UC Berkeley included the development of population genetic tools used to study admixture using ancient and present-day genome-wide data, as well assessment of these tools through simulation. The focus of my research is to synthesize these two directions, assessing the robustness of currently used population genetic tools applied to these data and uncovering more on genetic variation and history of different species, with a particular emphasis on humans.