Population biology is an interdisciplinary field that combines the most advanced techniques in ecology, systematics, genetics, and mathematical or statistical analysis. We work near the interface between ecology, the study of interactions between organisms and their environment, and evolutionary biology, which aims to understand how populations, species and species characteristics evolve. The results provide fundamental knowledge that increases our understanding of processes that cause populations to change and contributes to the development of effective solutions to such problems as overcrowding and species extinction. UC Davis offers this graduate program in Population Biology which leads to a Ph.D. Areas of specialization include population growth, structure and dynamics (basic and applied), population interactions (competition, predation, parasitism, and mutualism), community ecology, food webs, behavioral and physiological ecology, life history strategies, systematics, evolution, statistical phylogenetics (phylogeny and species-tree inference, divergence-time estimation, species delimitation), comparative methods (character evolution, historical biogeography, lineage diversification), population and quantitative genetics, and genomics. We encourage intellectual independence of students and the creativity that it encourages.