A fishing expedition 15 years ago off the west coast of Greenland led scientists to discover the world’s oldest vertebrate, Greenland sharks. This species can live at least 250 years. Scientists see lifestyle and genetics as a possible cause, and gene therapy techniques help humans adopt the same longevity.
Danish marine biologist John Steffensen was on a fishing expedition 15 years ago when he spotted an unusual-looking shark that hung from the boat’s edge. Greenland sharks are large, sluggish, and awkwardly proportioned sharks that roam the icy depths of the North Atlantic Ocean and the Gulf of Mexico.
Steffensen and his colleagues published their findings in a study titled “Eye Lens Radiocarbon Reveals Centuries of Longevity in the Greenland Shark (Somniosus microcephalus),” on Science in 2016. Since then, this cadaverous shark has become a sensation, with scientists worldwide trying to unlock the secret of its longevity, noting that it could show humans how to live long.
(Photo: Wikimedia Commons)
Close-up image of a Greenland shark taken at the floe edge of the Admiralty Inlet, Nunavut
Greenland Sharks Lifespan
According to Atlas Obscura, Greenland sharks were commercially hunted for their oil-rich livers during the first half of the 20th century. However, presently, fishers find them a nuisance since these species feed o valuable halibut. Sometimes, they also get tangled with fishnets that could damage equipment on deck if they could not find a way out.
Steffensen’s interest in Greenland sharks peaked when he learned of the extreme longevity of the sharks. They tried scanning the sharks for signs of growth rings but failed and found no evidence of their age.
So, he consulted retired physicist Jan Heinemeier from Denmark’s Aarhus University, who gave him the idea of dating eye lenses produced at birth and could be subjected to carbon dating.
The results were astounding, showing that Greenland sharks could live at least 272 years up to 512 years old. In the video by Wonder World, they discussed that the oldest Greenland shark was 512 years old found in the North Atlantic, which could also hold the record of being the oldest living vertebrate in the world.
The scientists at first could not believe their findings, questioning whether they have made a mistake or not. Another thing they observed is that older Greenland sharks grow at a slower rate than young ones. The largest they found was 16 feet long, but they could still grow up to 18 feet.
How Can Greenland Sharks Longevity Show Humans How To Live Long?
Finding out that there could be sharks swimming in the ocean born during the Renaissance period is extraordinary. Scientists have asked how these creatures could live that long. They believe it might be due to genetics and lifestyle.
According to NBC News, Greenland sharks’ longevity might have to do with their extraordinary heart and unique immune systems. The sharks’ hearts pump slowly by about one beat per 12 seconds, and they have been beating already for centuries. On the other hand, a human heart beats about once every second and gradually slows down as humans age.
Moreover, DNA sequencing of Greenland sharks shows that genetic mutations in them have given them an immune system that can stop cancer and other infectious diseases.
In the future, scientists hope to transplant the genes to humans to promote long life using gene therapy techniques. However, this technology is in its early years, and more studies are needed to be successful.
Check out more news and information on Sharks in Science Times.
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