PEOPLING

A Finger Bone Deep in Arabia

more than ~85,000 years ago

Palaeolithic · Middle Stone Age · Last glacial

In the Nefud desert of Saudi Arabia, on the shore of a vanished freshwater lake, surveyors found a single human finger bone. Directly dated to at least 85,000 years, Al Wusta-1 is the oldest directly dated Homo sapiens fossil outside Africa and the Levant. Its owners lived among a mostly African fauna, in grassland fed by monsoon rains, and nearby lake beds preserve human footprints from an even older wet phase, the last interglacial, some 120,000 years ago.

Why it matters

A bone the size of a thumb joint redrew the map of the human diaspora. The older model allowed early moderns only a short excursion into the Levant; Al Wusta puts them deep in the Arabian interior, following the rains into green grassland, tens of thousands of years before the dispersal that peopled the rest of the world. Arabia stops being a margin of that story and becomes one of its stages.

Dating & uncertainty

The bone was dated directly by uranium series, and a Bayesian model over independent methods gives about 95,000 to 86,000 years. The nearby Alathar footprints are dated by luminescence to the last interglacial; being tracks rather than bones, their attribution to our species is an argument, not an identification, and their makers left no skeletons.

Sources

1. Groucutt et al. (2018), Nature Ecology & Evolution · Homo sapiens in Arabia by 85,000 years agodoi:10.1038/s41559-018-0518-2
2. Stewart et al. (2020), Science Advances · Human footprints provide snapshot of last interglacial ecology in the Arabian interiordoi:10.1126/sciadv.aba8940
3. Henry (2018), Nature Ecology & Evolution · Joining the dotsdoi:10.1038/s41559-018-0539-x

Our species’ history as one day

17:26:516 h 33 min before midnight

if the 315,000 years of Homo sapiens were compressed into a single day