A vertebrate paleontologist, Polly combines quantitative techniques for measuring complex three-dimensional objects with computational modeling and phylogenetics to study the evolution of morphology. His research focuses on how functional performance, chance events and the legacy of ancestry contribute to morphological evolution, and how its course is influenced by the broad context of changing Earth systems, especially climate, landscape and tectonics. Measuring their complex forms has required a fusion of geometric morphometrics, quantitative genetics and phylogenetics, including developing new methods for quantifying their three-dimensional surfaces. Polly was president of the Society of Vertebrate Paleontology, associate director of IU’s Environmental Resilience Institute and an Edward P. Bass Distinguished Visiting Environmental Scholar at Yale University.