Professor Emerit Millstein's research is in the philosophy of science, the history & philosophy of biology, and environmental ethics. She is particularly interested in evolutionary biology, ecology, and environmental issues, and the intersections between them.
With respect to evolutionary biology, she has particularly focused on central processes in evolution such as natural selection, random drift, sexual selection, and social selection, as well as central concepts in evolution such as fitness, population, metapopulation, race, and environment. This has included analysis of the general philosophy of science concepts of chance, probability, causation, causal processes, and determinism/indeterminism, and the ways in which they manifest (or fail to manifest) within evolutionary processes. Her conceptual work has been informed by her historical work, which includes analysis of some central 20th century debates in evolutionary biology, such as the neutral and “nearly neutral” theories of evolution and the empirical study of the land snail Cepaea nemoralis in the wild.
With respect to ecology, she has examined the historical and contemporary connections between ecology and population genetics. As part of a more extensive research project, she has re-interpreted and defended the work of 20th century ecologist (forester, wildlife manager, conservationist) Aldo Leopold, analyzing land communities (roughly similar to biotic communities/ecosystems), interdependence, functions/functioning, and predator/prey dynamics. Inasmuch as these ideas arise in the context of Leopold's land ethic, this project is also a project in environmental ethics. She is currently working on a book length analysis and defense of the land ethic, tentatively titled The Land Is Our Community: A Land Ethic for the New Millennium. Other work in environmental ethics examines the implications of the environmental impacts of GMOs and argues for how we ought to think of the field of environmental ethics.