Brains aren’t particularly hardy organs. They bleed, they’re soft, they’re mostly made of fat, and when you die they quickly begin to break down. All of this means that archeologists aren’t digging up a lot of brains, compared to things like skulls and teeth. It also means that this 4,000-year old brain researchers just found in western Turkey is even more important than your run-of-the-mill 4,000-year-old piece of human.
It takes extreme conditions to get a brain to stick around. Two years ago, scientists found a 2,600-year-old brain in a bog, the wet, oxygen-depleted waters stopping it from breaking down. A different team of researchers found another brain, of a small child, in an icy mountain grave. But the Turkish person’s brain was preserved not by water or ice, but by fire. The team that found this one, says New Scientist, thinks that the person, trapped in rubble by an earthquake, was slowly burned.
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.
The final factor in the brains’ preservation was the chemistry of the soil, which is rich in potassium, magnesium and aluminium. These elements reacted with the fatty acids from the human tissue to form a soapy substance calledadipocere. Also known as corpse wax, it effectively preserved the shape of the soft brain tissue.
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