Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

Although individuals of a species are similar, they are rarely identical. Individuals differ from each other in many important ways. Those differences that are inherited through genes constitute genetic variation. Genetic variation is critical for species, and the populations that make them up, to survive and evolve. Our lab studies genetic variation and how it is maintained in populations of wild animals.

We are interested in two main factors that affect genetic variation. The first is population size. Population size is the number of individuals in a population, and is one of the most important things that determine genetic variation. Larger populations can hold more genetic variation than smaller ones. A drop in population size, because of a severe storm for example, can remove a lot of genetic variation. The second factor is the nature of the surrounding landscape. The landscape affects genetic variation by determining how easily individuals from other areas can move into a population, bringing new genetic variation with them.

Many researchers have looked at the separate effects of changes in population size and landscape on genetic variation. But, we do not have a strong understanding of how these processes interact. For example, are the effects of a drop in population size more severe if a population is surrounded by inhospitable landscape? Currently, human land use and climate change are simultaneously altering landscapes and making wildlife populations less stable in size. If we want to prevent harmful effects of these environmental changes, we need a better understanding of how they act in combination. Our lab’s goal is therefore to advance understanding of the combined effects of changes in population size and landscape on genetic variation in wild animals.

We will study a group of 16 populations of the Rocky Mountain apollo butterfly. Sizes of these populations have been measured each year for over 20 years. Over this time, population sizes dropped dramatically, and then recovered, on two occasions. Samples for genetic analysis have also been collected from these populations yearly. We will use these samples, and modern genomic methods, to measure genetic variation of the populations in different years. We will then look at how genetic variation has changed over time with changes in population size. We will also examine how those changes were affected by characteristics of the surrounding landscape that either block or promote movement of individuals among the populations.

These processes are much harder to track in animals that are longer lived or occupy larger areas on the landscape. Our research therefore provides a model for understanding combined effects of changes in population size and landscape on genetic variation in other animals. Our work is important for conservation because it will improve understanding of how human land use and climate change interact to affect wildlife.