Join us for a conversation with James DeGregori, Courtenay C. And Lucy Patten Davis Endowed Chair in Lung Cancer Research at the University of Colorado Anschutz Medical Campus. In the last five years, multiple studies have demonstrated that apparently healthy tissues in humans are patchworks of clones bearing somatic mutations, and the sizes and frequencies of these clones increases dramatically in old age. Often, there is clear evidence for positive selection for variants, which are frequently in genes frequently mutated in cancers, and yet the vast (VAST!) majority of these mutation-bearing clones will never develop into a cancer. We will discuss the implications of these findings for different evolutionary theories of aging and cancer.