Brain of Bronze Age Human Survives for 4000 Years
The brain tissue of a Bronze Age human has survived for more than 4,000 years, offering archaeologists hope that more ancient brain specimens may be recovered which could pave the way to the study of health in prehistoric times.
The remains were discovered in Seyitömer Höyük, a Bronze Age settlement in western Turkey, and constitutes one of the oldest brains ever found. Being able to study a preserved brain enables scientists to piece together the individual’s last hours and may also reveal any diseases or pathological conditions such as tumours and haemorrhaging.
It is extremely rare to find a preserved brain of this age because brain tissue is rich in enzymes which cause cells to break down rapidly after death. Under certain conditions, however, the process of decomposition can be slowed down. For example, brain tissue has been found in the preserved body of an Incan child sacrificed 500 years ago. Her body was found at the top of an Andean mountain where the body swiftly froze, preserving the brain.
In the case of the brain sample found in Turkey, it is believed that an earthquake flattened the settlement and buried its inhabitants before a 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 would have helped to prevent tissue breakdown.
These factors combined with the fact that the soil composition was high in potassium, magnesium and aluminium, caused the human tissue to create a substance called adipocere, or ‘corpse wax’, which preserves soft tissue.
"The level of preservation in combination with the age is remarkable," says Frank Rühli at the University of Zurich, Switzerland, who has examined medieval brain tissue. Rühli says that most archaeologists don't bother looking for the remains of brain tissue because they assume it is seldom preserved. "If you publish cases like this, people will be more and more aware that they could find original brain tissue too."