By Lindsay Rogers Greenland sharks are the longest living vertebrates in the world, capable of living up to 400 years. To put that in perspective, according to National Geographic, “There could be an individual in the ocean today that was alive during the 1665 Great Plague of London and George Washington’s presidential inauguration in 1789.” Yet, despite their longevity, Greenland sharks are also extremely rare. At least, sightings by humans are extremely rare. That’s due largely to the deep, Arctic waters they’ve been known to inhabit (which humans typically do not). We’re talking 7,200 feet …