In this talk, I will give a brief overview of research topics in the Theoretical Biology group. Then I will focus on joint work with my PhD student Peter Nabutanyi on eco-evolutionary dynamics of small populations. Small populations can suffer from genetic problems like inbreeding depression, mutation accumulation, and loss of genetic variation. I will present stochastic models for the joint dynamics of population sizes and allele frequencies in such populations. We explore under what conditions populations enter an eco-evolutionary extinction vortex where a decrease in genetic variation leads to population decline, which leads to even faster loss of genetic variation, and so on, until the population goes extinct. We will also quantify minimum viable population sizes for the long-term persistence of populations experiencing a combination of genetic problems of small population size.