What is the oldest living thing on Earth
When it comes to extremely long-lived life forms, trees and plants beat animals hands down every time.
Some animal species, such as the Galapagos giant tortoise, can live for almost two centuries, but there exist types of trees that are able to survive for much, much longer than that.
Actually dating trees by counting their rings might seem simple enough, but typically in order to do this it is necessary to chop the tree down, something that is obviously undesirable when you are attempting to find the world's oldest living organism.
One way to get around this is to use an increment borer - a special tool that can extract part of the tree's core without fatally damaging it. This, too, however is not without its risks, as evidenced by one particularly memorable mishap that occurred in the 1960s.
One scientist had been attempting to date a bristlecone pine tree when the drill bit snapped off inside the trunk. Not wishing to lose this expensive piece of equipment, he had the tree chopped down to retrieve it. It later turned out that that the tree had been 5,000 years old.
These days, some of the oldest known trees include a 2,222-year-old sacred fig tree in Sri Lanka and a 3,627-year-old Patagonian cypress tree in Chile.
The most ancient trees of all however can be found in California's White Mountains where many of the Great Basin bristlecone pines are believed to be more than 4,000 years old.
The oldest among them is thought to date back a staggering 5,067 years.