I grew up in northeastern United States and received my undergraduate degree at the University of California, Berkeley. I served as a Peace Corps volunteer in Peru, where I married Margaret Ziegenhagen, who was also in the Peace Corps. I received my Ph.D. in anthropology from the University of Wisconsin and taught at the College of William and Mary in Virginia and the University of California, Davis.
My long-term research focused on the ethnobiology, evolution, and conservation of native crops in their centers of origin and diversity, including potatoes in Peru, wheat in Turkey, and maize in Mexico. In addition to my academic work and field studies, I was Director of Anthropology at the US National Science Foundation and a Senior Scientist at the International Plant Genetic Resources Institute in Rome. My two children grew up and continue to live in California, as do Margaret and I.