In this video from Faces of America, historian Henry Louis Gates, Jr. examines how DNA can communicate ethnic identity in a manner that genealogy can’t always articulate. Gates meets with Joanna Mountain from the genetic ancestry firm 23 and Me to complete an admixture test. The test reveals not only ancestral geographical origins over a number of centuries, but also illustrates ethnic breakdown. Gates reveals the ethnic breakdown (in the form of a pie chart) of his guests including Meryl Streep, Stephen Colbert, Eva Longoria and Elizabeth Alexander.