I have adopted complementary approaches to inferring human demographic history utilizing human and non-human genetic data as well as cultural data. These complementary approaches form an interdisciplinary perspective that allows one to make inferences of human history at varying timescales, from the events that occurred tens of thousands of years ago to ones that occurred in the most recent decades and centuries. I used slow-evolving human DNA to study the peopling of the Americas tens of thousands of years ago; fast-evolving lexical data to address the origin of Semitic several thousand years ago; and fast-evolving JC virus genomes to investigate human demography within the most recent decades and centuries. In the first study, I used human mtDNA to infer the demographic history of Amerind populations and analyzed a multi-locus human DNA dataset to confirm important parameter estimates of the peopling of the Americas. My analyses produced a three-stage model for the peopling of the Americas that includes a long occupation of Siberia and a rapid expansion ∼16,000 years ago into the Americas from a founding population of ∼1000 to 5000 individuals. Second, I analyzed lexical data from 25 Semitic languages using computational phylogenetic techniques borrowed from evolutionary biology. Using the sampling dates of extinct languages, I was able to date events in the history of Semitic and place the origin of Semitic ∼5900 years ago in what is now Syria. My final project entailed the analysis of a large dataset of JC virus genomes (>400) and their associated sampling dates to infer the mutation rate and demographic history of JC virus. I estimated a surprisingly fast evolutionary rate for JC virus from the viral sampling dates, and confirmed this fast rate from Bayesian model tests. Ultimately, I was able to use the fast JC virus rate to infer a recent expansion of JC virus in regional populations that correlates with events in human population history of over the most recent decades and centuries.

Genetic anthropologists are uniquely equipped to appreciate the utility of combining genetic data with non-genetic or non-human data to investigate human history. This perspective allows genetic anthropologists to address questions that cannot be answered by human DNA alone by extracting as much information as possible from genetic analyses. Here, I provide examples of this integrative approach to studying human population history.