N. America's first settlers didn't dawdle

S.A. scientists determine land bridge from Asia just 'a bus stop.'

Scientists here are rewriting an early chapter of the history books that describes how and when humans first set foot on North American soil, based on clues extracted from the blood of their San Antonio descendants.

Experts agree — based on genetic evidence, bones, artifacts and the study of languages — that the ancestors of American Indians came from Northeast Asia thousands of years ago, crossing the frozen Bering land bridge, probably in pursuit of wild game...