What's the oldest living thing in the world? It's not an easy question to answer. Some animals and plants can survive for hundreds or thousands of years, and because nobody was around when they were born it can often be difficult to get an exact age, according to the BBC.

The oldest known animal, for which a precise age can be measured, is a clam discovered in Iceland in 2006. Clams are easy to age because scientists can count the number of rings on their shells. Unfortunately, this can often kill the clam, which is what tragically befell the world's oldest animal 11 years ago.

The Iceland clam, nicknamed Ming after the Chinese dynasty during which it was born, was measured to be 507 years old. Unfortunately, there's no way of telling how old the clam could have become had it not died. There could be many more clams in the depths of the ocean that are even older.

Some of the most compelling candidates—as well as some of the easiest to age—are trees. Many trees create annual tree rings that can be counted to find an exact age. By taking small cores out of the trees, scientists can accurately measure their ages without killing them. Using this method, scientists have found many trees that are thousands of years old.

Some of the oldest measured trees are a cypress in Chile that's over 3,600 years old, a handful of giant sequoias in California that are around 3,200 years old, and a pair of bristlecone pines in the White Mountains that are between 4,800 and 5,000 years old.

Those are the oldest single trees, but there's a tree in Utah that might be even older. The tree, nicknamed Pando, is a quaking aspen that has cloned itself so many times it's created an entire forest. It's theorized that many thousands of years ago, the original tree put down roots, which grew brand new trunks, which put out more roots, which grew more trunks, and so on. Now it's got an estimated 50,000 trunks—all technically from the same tree.

It's tough to say how old Pando is because each tree trunk has its own separate age, and the original trunk is almost certainly dead. Most estimates place the tree's age at around 80,000 years, though some estimates go as high as a million years old.

But even this might not be the oldest living thing. There's also this colony of Neptune Grass located off the coast of Ibiza, estimated to be around 100,000 years old.

No matter how old the oldest living thing really is, chances are we haven't found it yet and may never know for sure.

Source: BBC

From: Popular Mechanics