The Pine That Was a Sapling Before the Pyramids

Edmund Schulman, a dendrochronologist at the University of Arizona, cored a Great Basin bristlecone pine in California's White Mountains in the summer of 1957 and counted the rings. There were 4,789 of them. The tree had germinated around 2833 BC, three or four centuries before Khufu's pyramid at Giza was finished. Schulman wrote it up for National Geographic in March 1958 under the title "Bristlecone Pine, Oldest Known Living Thing."

He died of a heart attack three months before that issue ran. His co-author Tom Harlan inherited the cores. The tree, eventually nicknamed Methuselah, is still alive — somewhere in the Methuselah Grove, between 2,900 and 3,000 metres up in Inyo National Forest. The U.S. Forest Service refuses to identify which tree it is. After a 2012 vandalism case at a different ancient pine, the policy hardened.

Pinus longaeva gets old by giving up on growing fast. At that altitude, with thin soil and a short season, the trees lay down rings so tight they can pack 100 to an inch. The wood is dense, oily, and full of resin acids that resist insects and rot. When a bristlecone finally dies, its corpse can stay standing on the slope for another four or five thousand years before the wood weathers down to nothing.

That slow ring growth is also why Methuselah's cousins matter to physics. Calibrating radiocarbon dates requires a continuous tree-ring record back through prehistory; the bristlecones, alive and dead together, supply one extending past 9000 BC. The Egyptian Old Kingdom dates the rest of the world by carbon-14, and the carbon-14 is dated by the trees.