As the glaciers that once covered much of North America began to melt, ancient people took full advantage of the thriving, untouched continent that lay on the other side. How and when humans first made this foray is still disputed, but now new evidence in the form of the oldest human footprints found in North America lends support to the theory that we followed the coastline, rather than taking a route inland.
“This article details the discovery of footprints on the west coast of Canada with associated radiocarbon dates of 13,000 years before present,” explained Duncan McLaren, who led the study published in PLOS ONE. “This finding provides evidence of the seafaring people who inhabited this area during the tail end of the last major ice age.”
The footprints were uncovered in an intertidal zone on Calvert Island, British Columbia. The incredibly rare discovery is made up of 29 human footprints, representing at least three individuals including what is believed to be a child. As these people walked through soft sand, their prints were preserved when sediment was subsequently laid over the top as the tide came in.
The question of when – and more specifically how – humans first arrived in the Americas has been one of fierce debate. While genetics suggest that the indigenous Americans split from the northeastern Asians some 35,000 years ago, direct archaeological evidence of these first peoples has been scant and often highly contested.
It is generally thought very unlikely that people were living in North America as long as 35,000 years ago. Instead, it's thought that the population of people who would eventually go on to colonize the Americas first became isolated in Asia, and later further so on the land bridge known as Beringia, which connected the two continents at this point in time. They then moved into the Americas when the environmental conditions allowed it.
It is this last bit where most disagreements come to a head. We know that massive glaciers covered much of northeastern America during the last ice age, and started retreating around 15,000 years ago.
The question is, did people migrate into the Americas when an ice-free corridor opened up along the line of the Rockies, or did they follow the Pacific coastline when the glaciers retreated from the ocean edge? With so little archaeological evidence from this period of time coming out of the Americas, it has been a pretty difficult question to answer.
This is why the discovery of ancient human footprints from the Canadian Pacific coast is of such significance. While it is true that the footprints are only a single data point, and so are limited in what they tell us, it does suggest that people were living in – or at least exploring – the coastal environment at the time it is thought the Americas were first settled.