Molly received a B.A. in Mathematics from Princeton University and a Ph.D. from the Committee on Evolutionary Biology at the University of Chicago, working with Brian Charlesworth and Dick Hudson. Her postdoc was in the group of Peter Donnelly in the Statistics Dept. of the University of Oxford, and was followed by a two year stint as a research scientist at the Max Planck Institute for Evolutionary Anthropology. Before moving to Columbia University, she was a faculty member at the University of Chicago (where she was also a Howard Hughes Medical Institute Early Career Scientist) as well as, briefly, at Brown University.