© Halic University Istanbul
No burnt log
Shaken, scorched and boiled in its own juices, this 4000-year-old human brain has been through a lot.
It may look like nothing more than a bit of burnt log, but it is one of the oldest brains ever found. Its discovery, and the story now being pieced together of its owner's last hours, offers the tantalising prospect that archaeological remains could harbour more ancient brain specimens than thought. If that's the case, it potentially opens the way to studying the health of the brain in prehistoric times.
Brain tissue is rich in enzymes that cause cells to break down rapidly after death, but this process can be halted if conditions are right. For instance, brain tissue has been found in the perfectly preserved body of an Inca child sacrificed 500 years ago
. In this case, death occurred at the top of an Andean mountain where the body swiftly froze, preserving the brain.
However, Seyitömer Höyük - the Bronze Age settlement in western Turkey where this brain was found - is not in the mountains. So how did brain tissue survive in four skeletons dug up there between 2006 and 2011?
at Haliç University in Istanbul, Turkey, who together with colleagues has been analysing the find, says the clues are in the ground. The skeletons were found burnt in a layer of sediment that also contained charred wooden objects. Given that the region is tectonically active, Altinoz speculates that an earthquake flattened the settlement and buried the people before fire spread through the rubble.
The flames would have consumed any oxygen in the rubble and boiled the brains in their own fluids. The resulting lack of moisture and oxygen in the environment helped prevent tissue breakdown.