Oxford researchers find DNA in ancient clay brick

Aug 25, 2023

Researchers have extracted ancient plant DNA from a 2,900-year-old clay brick.

Experts at the University of Oxford collected samples from the artefact's inner core, which uncovered a "time capsule" of vegetation life.

The brick, from the ancient city of Kalhu in Iraq, would have been made primarily of mud and mixed with chaff, straw or animal dung.

Some of the plant families uncovered included cabbage, heather, and birch.

The samples were taken during a project at the National Museum of Denmark in 2020, using a method previously used for other porous materials, such as bone.

The brick, thought to be from between 879 BCE and 869 BCE, would have been shaped in a mould before being inscribed with cuneiform script - an ancient form of writing - and left in the sun to dry.

Researchers said the fact the brick was never burned, but left to dry naturally, would have helped to preserve the genetic material trapped within the clay.

The findings give an insight into the different plant species grown in that part of the world at the time.

The writing on the brick reads: "The property of the palace of Ashurnasirpal, king of Assyria" and experts believe it was from the king's palace.

Dr Sophie Lund Rasmussen from the University of Oxford's Department of Biology said she was "thrilled" at the findings.

She said: "The research could be applied to many other archaeological sources of clay from different places and time periods around the world, to identify past flora and fauna.

"Clay materials are nearly always present in any archaeological site around the world."

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