It's the New Year, and we are another year older. Most humans live within a century, but some animals take that to the max. Some animals can live for hundreds to even tens of thousands of years. But nothing can live forever… or is there someone who disproves that? Does that natural world have the secrets to a long life that humans have been endeavoring to find throughout our existence? Let's get into it!
In the Early 1600s, Jamestown was a new settlement in the New World Colonies, Galileo was discovering evidence that the sun was the center of our solar system, William Shakespeare passed away, and a female Greenland shark was hatched. Normally fish are aged by counting the rings on their ear bones called otoliths, but Greenland sharks don’t have any hard calcified sections. Researchers were able to use carbon dating on proteins that formed in the shark’s eye when she first hatched to estimate her age to be about 400 years old. It's thought the secret to their longevity is that they live their lives slowly. They move slowly in the cold northern waters, only about 1.8 mph (3 kph), and their slow metabolisms cause them to reach sexual maturity when they’re over a century old.
But this is not the oldest animal. In 1498, Christopher Columbus was beginning his third expedition to the new world, and a little clam named Ming the Quahog was born. Clams are aged just like fish and trees, by counting the rings on their shells that mark each year of their life. Ming was found in the Icelandic oceans. In addition to being in cold water, the secret to Ming’s longevity seems to be in their resistance to oxidative stress. Metabolic processes in our bodies create molecules called free radicals that damage proteins, and tissues, and even lead to cell death. It's thought that this is what leads to aging. Ming’s species, Arctica islandica, seems to not create as many free radicals even when exposed to the same stressors as other species, protecting their cells, and promoting their longevity. Free radicals damage proteins and tissues by removing electrons from the structural molecules, which causes them to change their form and not function properly. A way we can protect ourselves from the damaging effects of free radicals is to consume antioxidants in fruits and vegetables, who donate electrons, protecting protein structure and cell function.
Above image is not Anoxycalyx joubini
15,000 years ago, humans were just beginning to reach North America, and Mammoths were still roaming the earth in the last few millennia of the most recent ice age. At this time, a small sponge called Anoxycalyx joubini, the most basic multicellular animal, was beginning its life in the cold Antarctic waters. They are difficult to study because they can be found very deep in cold waters and their longevity is still in question. But it's thought that the cold waters and the pressure slow their growth to a rate where there can be no measurable growth in more than a decade. They also get by with a little help from their friends, who are symbiotic cyanobacteria and dinoflagellates, who live inside the sponges and create energy from chemicals or sunlight. So perhaps their secret is to take life slowly and don’t live it alone.
But humans don’t want to live just for a long time, for centuries kings and emperors searched for the secret to live forever, and it seems that one animal has figured out how to do just that. As life goes on, our bodies are damaged from various factors like the environment, oxidative stress, etc., and the collection of these stressors slowly age us. The Immortal Jellyfish, Turritopsis dohrnii, has learned how to turn back time when they are damaged or stressed. Jellyfish aren’t always free swimming organisms. When they hatch from their eggs, they attach to a surface and grow into a polyp, which look similar to anemones. Once they develop enough, they then detach from the surface and transform into the medusoid form, which is the classic jellyfish form we recognize. The immortal jellyfish has evolved to transform back into their polyp form when they are at risk of dying, turning back the clock on their lifecycle, and eventually transforming back into their medusoid form. This makes their lifespan theoretically forever. Although it's not possible for humans to mimic behaviors like this to promote our own longevity, scientists are studying them for medical applications for diseases associated with aging.
Nature is filled with amazing animals who force us to rethink what is possible. These long lived animals are filled with wisdom that we can learn and apply in our own lives. Although we can’t live forever, our actions and behaviors can promote a long and healthy life. Plus it's just impressive to think about how long some of these creatures have been around. So what changes can you make in your own life to promote longevity and health?
Ming the Mollusk
Ungvari, Zoltan et al. “Extreme longevity is associated with increased resistance to oxidative stress in Arctica islandica, the longest-living non-colonial animal.” The journals of gerontology. Series A, Biological sciences and medical sciences vol. 66,7 (2011): 741-50. doi:10.1093/gerona/glr044
Pizzino, Gabriele et al. “Oxidative Stress: Harms and Benefits for Human Health.” Oxidative medicine and cellular longevity vol. 2017 (2017): 8416763. doi:10.1155/2017/8416763
Giant Volcano Sponge