Research involving ancient DNA has experienced a true technological revolution in recent years through advances in the recovery of ancient DNA and, particularly, through applications of high-throughput sequencing. Formerly restricted to the analysis of only limited amounts of genetic information, ancient DNA studies have now progressed to whole-genome sequencing for an increasing number of ancient individuals and extinct species. In this talk I will provide an overview of recent findings done by my group. This concerns what we have learned on early peopling of the Americas, early peopling of Eurasia, and Australia as well the more recent human history of Europe and central Asia. I will also talk about some of our studies related to the population dynamics and extinction of the big bodied mammals (megafauna) around the end of the last Ice Age.