"Unless you were one of the first Americans, a Native American, you came from someplace else, somebody brought you," President Barack Obama told the assembled throngs in Las Vegas on Tuesday. Perhaps to make sense of the empty phrase "Native American," Obama seems to have overlooked the most contentious debate in modern archaeology: when did the first waves of humanity reach the Americas and where did they come from?   The only real consensus among archaeologists is that everyone in America came from "someplace else."  Or as the Bill Murray character memorably said in Stripes, "We're Americans, with a capital 'A', huh? You know what that means? Do ya? That means that our forefathers were kicked out of every decent country in the world." For years, the "Clovis First" hypothesis held sway in the academy.  This school argued that the so-called Clovis people (they didn't call themselves that) crossed the land bridge from Siberia to Alaska during the most recent ice...(Read Full Post)