Jennifer Raff celebrated anthropologist reports 20,000 years ago, people crossed a great land bridge from Siberia into Western Alaska and then dispersed southward into what is now called the Americas. Until we venture out to other worlds, this remains the last time our species has populated an entirely new place, and this event has been a subject of deep fascination and controversy. No written records—and scant archaeological evidence—exist to tell us what happened or how it took place. Join us when Jennifer Raff examines her study if many different models which have been proposed to explain how the Americas were peopled and what happened in the thousands of years that followed on this installment of Leonard Lopate at Large