This proposal will support the training of graduate students in the areas of mathematics and biology. The focus of the research area will be the dynamics of heterogeneous ecological and evolutionary systems, with an emphasis on spatial and temporal heterogeneity. The focus will be on deterministic and stochastic models across broad organizational and temporal scales. Students will be expected to gain expertise in either deterministic or stochastic mathematical techniques, in computational methods and statistics, and in an area of specialization in biology. Students may major in one of several biological fields, with a formal minor in a mathematical field or they may major in one of the mathematical fields, while undertaking field or laboratory research, and satisfying the formal requirement for a biology minor. Students will be trained through an integrated program, involving mathematicians, ecologists, and evolutionary biologist with a demonstrated capacity to cross the boundaries between their disciplines.