Pigliucci was formerly a professor of ecology and evolution at Stony Brook University. He explored phenotypic plasticity, genotype-environment interactions, natural selection, and the constraints imposed on natural selection by the genetic and developmental makeup of organisms. In 1997, while working at the University of Tennessee, Pigliucci received the Theodosius Dobzhansky Prize, awarded annually by the Society for the Study of Evolution to recognize the accomplishments and future promise of an outstanding young evolutionary biologist. As a philosopher, Pigliucci is interested in the structure and foundations of evolutionary theory, the relationship between science and philosophy, and the relationship between science and religion. He is a proponent of an extended evolutionary synthesis to unify parts of biology not covered by the "modern synthesis" of the 20th century.