Episode: 1SummaryLearn about the deep evolutionary origin of birds and follow their history up to the great extinction that happened 66 million years ago.First, I discuss what we mean when we say \u201cbird.\u201d What characteristics separate modern birds from other animal groups?Then I discuss the evidence\u2014both historical and recent\u2014that scientists have used to determine the evolutionary history of birds. Finally, we arrive at the answer of where birds fit on the tree of life.Research CitationsD...