Western science and medicine have historically ignored and underestimated the traditional knowledge of Native people, said Katrina Claw, a Navajo geneticist at the University of Colorado’s Anschutz Medical Campus. Many people in the community have a deep knowledge of biology and heredity, grounded in expertise in raising livestock and crops passed down over generations. The Navajo clan system, a way of identifying oneself that also keeps track of kinship, is a complex genealogical and cultural system and a form of genetic knowledge, Claw said.