IT ISN'T AN EASY DRIVE from Alberta to Baja California, but Ruth Gruhn and Alan Bryan, archaeologists from the University of Alberta (and husband and wife), have been making the journey since 1991. The barren desert peninsula is the spot they chose to test the theory that the earliest settlers of the Americas traveled by boat, not on foot. Their excavations at two rockshelters have yielded tantalizing results. They have found evidence of human occupation at the early Holocene--about 9000 RCYBP (10,500 calendar years ago)--and they have hopes of pushing dates back even further.

Why walk when you can paddle?
The theory they are testing is the coastal-entry theory of migration, first proposed by archaeologist Knut Fladmark of Simon Fraser University nearly 30 years ago. Dr. Gruhn supported the theory more than a decade ago, before the collapse of the Clovis-First model--and even made a convert of Dr. Bryan. In recent years increasing numbers of North American archaeologists have become supporters of the theory.

The coastal-entry model cuts through complicated theories contrived to explain how humans crossed the Bering land bridge on foot, how they found a route through the Cordilleran and Laurentide Ice Sheets to the temperate areas of North America, and what they found to eat during their journey. Even enthusiastic Clovis-First advocates admit it wasn't an easy journey, and the timing was crucial, since their model depends on an Ice-free Corridor between the glaciers at the time of the supposed trek.



Why couldn't the first Asians have made the trip by boat instead? Dr. Fladmark contends that the trip would have been possible anytime during the last 60,000 years. Smithsonian archaeologist Dennis Stanford points out that "everyone knows boats have been around for 50,000 years" (MT 17-1, "Immigrants from the Other Side?"). It needn't have been an unremittingly arduous journey, since the coast along the Pacific Northwest had ice-free pockets that could have provided relief for southbound voyagers. And instead of relying on megamammals for food (that image of the Paleoamerican hunter with spear stalking woolly mammoths is a hard one to shake loose), the colonizers could have been conditioned to subsisting on bounty furnished by the sea--mollusks, fish, and the birds and mammals that fed on them.

The coastal-entry theory has an especially attractive advantage over models that have humans traversing the continent--and the entire hemisphere--on foot: speed. Paul Martin's prehistoric-overkill hypothesis, for example, contends that humans made the crossing from Beringia about 12,000 RCYBP (14,000 calendar years ago), then developed sophisticated stone-tool technology that made possible rapid population growth. Martin believes that, thanks to their efficient hunting tools, the first Americans reached the tip of South America as early as 1,000 years later. For Fladmark's boat people, that's a snail's pace. "Even primitive boats," he submits, "could traverse the entire Pacific coast of North and South America in less than 10-15 years."


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