The migration of homo sapiens from Africa to the rest of the globe is an enduring point of fascination for archaeologists, who have been piecing together human movements across history since the dawn of the discipline. A new study published in Nature last week has helped unlock another piece of the puzzle.
That study, conducted by a research team led by Fa-Gang Wang, is an examination of Xiamabei, a 40,000-year-old archaeological site in northern China. At this site, researchers discovered evidence of a culture that processed ochre, which is used to make pigments. The discovery may seem like a small one, but it led the researchers to rethink how modern humanity evolved.
Ochre is a pigment found in clay, and its presence at archaeological sites suggests the people who lived in Xiamabei had advanced cognitive skills, partly because its points to creativity. However, the pigment can also be used to more practical ends, such as tanning hides.
At Xiamabei, researchers discovered that the humans at the site brought different deposits of ochre there and processed it through pounding and abrasion. This resulted pigments of varying color and consistency. Evidence of the pounding was found on a limestone slab where this processing took place. These humans produced such large quantities of ochre that the slab was stained with pigment.
The unique nature of the tools and processing method found at Xiamabei suggest that instead of one continuous wave of migration across Asia, colonization of this territory happened in distinct phases, the researchers said. “Our findings show that current evolutionary scenarios are too simple,” Michael Petraglia of the Max Planck Institute said in an interview with Science Daily. “Modern humans, and our culture, emerged through repeated but differing episodes of genetic and social exchanges over large geographic areas, rather than as a single, rapid dispersal wave across Asia.”
Another clue as to this disjointedness is what the researchers didn’t find: formal bone tools and ornaments, which were available at the time, but which evidently were not used by some of Xiamabei’s oldest inhabitants.