All About Mitochondrial Eve: An Interview with Rebecca Cann

In unearthing the genetic history of human populations, the recent pace of discovery has been so rapid that we can lose sight of the impact made by a single paper. In a 1987 Nature article, Rebecca Cann and her co-workers, Mark Stoneking and the late Allan Wilson, painstakingly analyzed mitochondrial DNA purified from placentas that had been collected from women of many different ancestral origins. By comparing the mitochondrial DNA variants to each other, the authors produced a phylogenetic tree that showed how human mitochondria are all related to each other and, by implication, how all living females, through whom mitochondria are transmitted, are descended from a single maternal ancestor. Not only that, they localized the root of the tree in Africa. The report left a wake, still rippling today, that stimulated not just geneticists and paleo-anthropologists, but the layperson as well, especially as the ancestor was quickly dubbed ‘‘Mitochondrial Eve.’’ Indeed, the cover of Newsweek one year later depicted an Eden, replete with apple tree and serpent, but with the iconic blonde couple of Dürer now supplanted by an Adam and Eve of African descent. I have always marveled at this paper, particularly as I had gotten to know Becky Cann (Image 1) when she was in the throes of completing this study and writing up the 40-something draft for its publication. At the time, I didn’t appreciate the magnitude of what Becky had accomplished or the implications of the work. When the American Society of Human Genetics meeting was held in Honolulu in October, I arranged to interview her in her lab at the University of Hawaii to elicit her reflections on this discovery. We met in the late afternoon, as students came by to submit their term papers under the 4 p.m. deadline. Becky has a kind of earth-mother quality about her, plainspoken, clear-thinking, and supportive of her students. Still active in the field of human origins, Becky has also branched into avian work, examining the phylogeny of endangered species of native Hawaiian birds in Hakalau Forest National Wildlife Refuge with her husband and collaborator, Lenny Freed. The University’s concrete campus lies deep within a canyon, its hard edges softened by mist and vegetation. Becky seems to fit right into the environment, fully grounded and far enough from the fray to follow her own path. Gitschier: I noticed on your CV that you went to high school in San Francisco. Did you grow up there? Cann: No, my parents moved from Des Moines, Iowa to San Francisco the summer before I started high school. My