I want to test the ability of students to read a passage and answer questions about it. Could you please come up with a good question for the passage "Indigenous genetic studies suggest that the first inhabitants of the Americas share a single ancestral population, one that developed in isolation, conjectured to be Beringia. The isolation of these peoples in Beringia might have lasted 10–20,000 years. Around 16,500 years ago, the glaciers began melting, allowing people to move south and east into Canada and beyond. These people are believed to have followed herds of now-extinct Pleistocene megafauna along ice-free corridors that stretched between the Laurentide and Cordilleran Ice Sheets."? 

Tracing the people's steps back north and west leads researchers to believe that they may have began where?