Research in the Holland laboratory is centered around the ecology and evolution of interspecific interactions. We are particularly interested in the influences of mutualism on patterns and processes across populations, communities, and ecosystems. Our aim is to develop a mechanistic understanding of these patterns and processes, ranging from the ecological and evolutionary stability of pairwise mutualisms to the structure and dynamics of multi-species mutualistic networks. The concepts and questions that motivate our research are studied using both theoretical and empirical approaches, including experiments, long-term monitoring, and natural history studies in the field. We are interested in a wide range of mutualisms, but our studies most commonly involve plant-insect interactions. While much of our research is focused on mutualism, we are interested in a diverse set of topics, including demography, population dynamics, density dependence, functional responses, interspecific population regulation, consumer-resource interactions, plant-animal interactions, geographic mosaic of species interactions, food webs, coevolution, pollination ecology, plant reproductive biology, and the ecology of the Sonoran Desert.