HUMAN EVOLUTION

Dmanisi: the First Departure

~2.1 to 1.8 million years ago

Phanerozoic · Cenozoic · Quaternary · Pleistocene · Gelasian

Hominins, members of the human lineage, left Africa long before our species existed, and small-bodied, small-brained hominins lived at Dmanisi, in the Caucasus, among sabre-toothed cats and giant hyenas about 1.8 million years ago.

The first departure is the spread of hominins out of Africa and across Asia, long before our own species existed. The oldest evidence is at Shangchen, on the Chinese Loess Plateau, where Zhu and colleagues (2018) found seventeen layers of stone tools, the oldest dated to 2.1 million years ago. Loess is wind-blown dust that accumulates in layers that can be dated in sequence, and it provides the chronology. No bones accompany the tools, so their makers are not identified. The best-dated hominins outside Africa are younger. They lived at Dmanisi, in the Caucasus, were small in body and small in brain, and lived among sabre-toothed cats and giant hyenas.

Why it matters

The exit from Africa required adapted lower limbs and a tolerance for open environments. It required neither a large brain volume nor a modern morphology, that is a modern body shape. The makers of the Shangchen tools were present in China three hundred thousand years before the oldest identifiable skeleton outside Africa. The first departure is therefore older than the first hominin outside Africa that can be identified.

Dating & uncertaintyDisputed

The bones and tools of Dmanisi, in Georgia, are securely dated to 1.8 million years ago. Stone tools from the Chinese Loess Plateau are older, 2.1 million years old, but no hominin fossil has been found with them. It therefore remains an open question whether the first hominin to leave Africa was already Homo erectus, an extinct human species.

Earth history as one day

23:59:2040.0 s before midnight

if Earth’s 4.54 billion years were compressed into a single day