The stratum that preserved the bones was accessible to erosion in Arlington Canyon in 1959.

A chain of contingencies — death near a stream in a canyon, deposition in alluvial sediment, preservation by the chemistry of the specific environment, erosion by the canyon’s modern stream, recognition by a trained archaeologist, preservation for future dating — led from that long-ago death to the modern scientific record.

Had any link in that chain been different — had the person died and been buried at the shore, had the canyon not eroded to expose the bones, had Orr not recognized their significance — the terminal Pleistocene record of the California coast would be that much thinner.

The remains of the Arlington Springs individual, in this sense, are not just evidence of one person.