Two U.S. scientists have published a radical new theory about when, where and how humans migrated to the New World, arguing that the peopling of the Americas may have begun via Canada's High Arctic islands and the Northwest Passage -- much farther north and at least 10,000 years earlier than generally believed.

The hypothesis -- described as "speculative" but "plausible" by the researchers themselves -- appears in the latest issue of the journal Current Biology, which features a special series of new studies tracing humanity's proliferation out of Africa and around the world beginning about 70,000 years ago.

The idea of an ancient Arctic migration as early as 25,000 years ago, proposed by University of Utah anthropologists Dennis O'Rourke and Jennifer Raff, would address several major gaps in prevailing theories about how the distant ancestors of to-day's aboriginal people in North and South America arrived in the Western Hemisphere....