Scientists have discovered the earliest evidence of Alaskan Ice Age humans fishing and feasting on salmon.

The findings contradict past beliefs that Ice Age Paleoindians exclusively hunted big game, the University of Alaska Fairbanks reported. The findings were made when anthropologist Ben Potter and colleagues stumbled upon 11,500-year-old chum salmon bones among scattered human remains and ancient tools.

"Salmon fishing has deep roots, and we now know that salmon have been consumed by North American humans at least 11,500 years ago," said lead author Carrin Halffman, a UAF anthropologist who helped analyze the fish bones.

The findings also suggest salmon runs were established much earlier and farther north than commonly believed. DNA and isotope analyses of the ancient material revealed ancient sea-run chum salmon migrated 870 miles upriver, suggesting the roots of modern salmons' migration dates back to the most recent Ice Age.

"We have cases where salmon become landlocked and have very different isotopic signatures than marine salmon. Combining genetic and isotopic analyses allow us to confirm the identity as chum salmon, which inhabit the area today, as well as establish their life histories," said Potter. "Both are necessary to understand how humans used these resources."

The salmon bones were discovered in an ancient cooking hearth discovered within a residential structure, which means ancient Beringian diets were likely more complex and varied than past evidence has revealed. The researchers noted there is no reason not to believe the salmon runs were present in the region 1,000 years prior to the time humans showed up.

"This suggests that salmon fishing may have played a role in the early human colonization of North America," Potter said.

The findings were published in a recent edition of the Proceedings of the National Academy of Sciences.