What is the oldest living thing on earth?

Is it a person? a tree? a spore? a bacteria? or something in the back of the refrigerator? There are few certain answers but that doesn't keep us from guessing. Actually scientists in a variety of fields from geology to forestry have been searching and measuring.

Not counting Methuselah, we humans have a hard time cracking 100 years of age. Most people don't make it that far; those that do get their pictures in the paper.

The current record holder is Edna Parker at 115 and counting. The prior record holder was Yone Minagawa, who passed away at 114. The title is a hard one to hold on to as we've had five "oldest" in a year!

Life expectancy is a moving target, thankfully moving upward. I picked up some numbers from Wikipedia, which lists overall life expectancy at birth in years. The world average is 67.2. Japan leads the list of countries at 82.6, and the last country is Swaziland at 39.2.

We're talking about a single plant here; one that reproduces externally - flowers, seeds. There are a few candidates including a creosote bush in the Mojave Desert, placed by some at 11,000 years old. However, most scientists agree on the Bristlecone Pine. Genus: Pinus, Species: longaeva.

How old? Dr. Edmund Schulman dated an individual tree in the White Mountains in California at over 4,700 years. This tree is nicknamed Methuselah, and it's location is kept secret to protect it.

Amazingly, this long living species, seems to thrive in the some of the harshest conditions. They are found in several US mountain ranges, typically at the 11,000 foot level. That is some very windy, very cold territory!

The oldest may also be the biggest, and it's another tree - the Quaking Aspen. Individual aspen don't have an unusually long life, but the total organism lives on and on. Unlike other trees that grow from seeds, this aspen reproduces by sending out lateral roots, that then pop up new aspen tree stems. They look like independant trees but are actually like branches of the main plant. The process is called suckering.

How old? The Pando in Utah is thought to be 80,000 years old. How big? The Pando is estimated to weigh 6,615 tons. That's one big sucker!

In Tasmania, we have the Kings Holly which is another sterile plant with no flowers, no seeds. The Kings Holly reproduces by root suckering and produces one big plant.

How big? 1-2 kilometers. How old? Estimated at 43,000 years, by the Tasmania Parks and Wildlife Service.

Then we have some spores contained in sea salt in Carlsbad, NM. Scientists can crack open these spores and find bacteria in suspended animation. Reactivate the bacteria and we have a living thing that can reproduce, B. permians.

How old? Try 250 million years!

Ooops - this one is also a little controversial as some other scientist think that no bacteria can remain viable this long, and that Mr. B. permians is actually contamination from the salt that isn't that old.

A quahog clam was dredged from the Arctic waters off the coast of Iceland. It's age was calculated to be 405 years! Apparently you can see and count growth lines on the clams shell. Scientists are studying these growth lines as part of research on climate change.

This particular clam ends up in the record books instead of on the dinner table.

Records like these generally come from zoos and aquariums. Conditions in the wild would alter numbers, but these are good for order of magnitude:

Mammal, excluding human - an elephant lived for 69 years.

Bird - a turkey buzzard lived to 118 years and a swan to 102.

Reptiles - we have a giant tortoise that crept around for 152 years.

Amphibians - a giant salamader lasted 55 years.

Fish - no surprise that a catfish lived 60 years.

Insect - cicada is on the list for 17 years, but I saw somewhere that a queen ant lived for 25 years, as her colony came and went.

Hmmm, it seems like being big (elephant, giant tortoise) and beligerant (swan) helps. Being a good sleeper works for the cicada.