Do Mega Sharks Still Exist?
This week, we’ve got a special video from our friends at the American Association of Chemistry Teachers, Featuring Sam Kean, the best selling author behind The Disappearing Spoon. Enjoy! While science has done wonders in solving mysteries about the world, sometimes people twist those discoveries into outlandish conclusions. Instead of using evidence to prove a point, people who believe in what’s called pathological science use ambiguity as evidence claiming that scientists don’t know everything, and therefore there’s room for my pet theory, too. That’s exactly what happened with manganese and the megalodon. In 1873 a research vessel called the HMS Challenger set out from England to explore the pacific ocean and pulled in tons of rocks, some shaped like mineralized ice cream cones. They were made of manganese. When the crew cracked open the cones they revealed the biggest, most pituitarily freakish five-inch shark teeth they’d ever seen. These teeth were later discovered by paleontologists to belong to the long extinct, fifty-foot long, fifty-ton megalodon. All fine science so far. The pathology started with the man- ganese. It’s not clear why manganese galvanizes shark teeth—that is, why thin layers of this metal deposit themselves on the teeth over time. But scientists do know how quickly the metal accumulates, and they deduced that the teeth date from at least 1.5 million years ago, meaning the megalodons probably died out around then. But some megalodon teeth had a mysteriously thin manganese plaque, about eleven thousand years’ worth. Evolutionarily, that’s an awfully short time. And really, what’s to say scientists won’t soon find one from ten thousand years ago? Or eight thousand years ago? Or later? In the 1960s, a few enthusiasts with Jurassic Park imaginations grew convinced that rogue megalodons still lurk in the oceans. “megalodon lives!” They cried. So why do people never see them? Well, this myth suggested that megalodons are supposed to be elusive, which gives people a convenient escape hatch when asked why the giant sharks are so scarce nowadays. Unfortunately for big shark dreamers, the idea crumbles under scrutiny. Among other things, the teeth with thin layers of manganese were almost certainly torn up from old bedrock beneath the ocean floor and exposed to water only recently. They’re probably much older than eleven thousand years. And although there have been legendary eyewitness accounts of the beasts, they’re all from sailors, notorious storytellers, and the megalodons in their stories vary manically in size and shape. Overall, such stories depend on subjective interpretations, and without objective evidence, it’s not plausible to conclude that megalodons, even a few of them, slipped through evolution’s snares. The Disappearing Spoon by Sam Kean is available at fine book stores everywhere. Want more episodes of The Disappearing Spoon series? Head to teachchemistry.org and join the AACT.