But the salmon bones document something different: the continuity of a specific relationship between people and a specific ecosystem, maintained across thousands of years and expressed in practices that are alive and functional in the contemporary world.

This is the kind of continuity that genetic analysis cannot capture but that is equally real and equally important for understanding what the first Americans were and who their descendants are.

The Kelp Highway And Its Consequences

The coastal migration hypothesis — sometimes called the kelp highway hypothesis because of the productive kelp ecosystems that would have lined the deglaciated Pacific coast — has been gaining support from multiple lines of evidence over the past two decades.

The USR1 discovery does not directly address the coastal route, but understanding how USR1 fits within the broader context of early American migration requires engaging with the coastal hypothesis and its implications.