Salmon snacks sent Stone Age settlers south.

New Scientist reveals how the first Americans made their way into Alaska and down… by eating salmon along the way:

The bones were discovered in a hearth inside a house at the Upward Sun River site, the exact location where human remains were previously found of two buried infants and a cremated 3-year-old boy.

Fish bones are fragile and not typically well preserved over time, but here they appear to have been rapidly buried and thus protected from acidic forest sediments.

Using DNA analysis, researchers identified the remains as chum salmon. An examination of carbon and nitrogen isotopes showed that they had migrated upriver from the sea.

Carrin Halffman of the University of Alaska Fairbanks says the findings add to growing evidence that counters the view of early North American settlers as specialist big-game hunters.