For much of the past century, the prevailing explanation for how the earliest inhabitants reached North America seemed firmly established. Generations of students learned the same straightforward story: during the last Ice Age, when sea levels were lower, a land bridge known as Beringia connected Siberia to Alaska. Early humans, following migrating animals, crossed this landmass and eventually populated the entire Western Hemisphere.
It was a clean narrative — concise, predictable, and easy to organize into textbook diagrams and museum displays.

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