Maryellen Ruvolo, professor of anthropology, specializes in the analysis of human and primate family trees using DNA data, a subfield of molecular evolution. She is probably best known for her work showing that people are more closely related to chimpanzees than to gorillas, contrary to previous thinking. She has also worked on the search for humankind's common roots, the ancestral Eve, whom most anthropologists now believe lived in Africa between 100,000 and 200,000 years ago. Ruvolo's research also involves the analysis of the AIDS virus in chimpanzees who become infected with the virus but who do not develop the disease's deadly symptoms. She is also continuing her work on the primate family tree, focusing her efforts on the expansion of the New World monkeys, found in South America, and of Old World monkeys, found in Africa and Asia.