Shark’s Great Status Has Smaller Origins

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With the status of Great White sharks increasing in the waters off of the Eastern US and Canada, people are turning their wary eyes to the beaches of the Atlantic. As wary as the public may be, this influx of the species is piquing the curiosity and excitement of oceanographers, biologists, and other scientists, wondering if the sharks are coming to roost. While Atlantic beach-goers are wondering if this return will bring with it a rise in shark attacks, scientists are making their best efforts to reassure citizens of the Northeast that the Great White sharks — while certainly imposing beasts — are not nearly the threatening versions that Hollywood originally implanted in the public’s collective minds.

One of the reasons the Great White earned its status as big, mean, eating-machine is because — much like the common, domesticated house cat — the shark compulsively “test-tastes” just about everything that offers any sign of electro-reception. The Great White has thousands of small receptor cells throughout the lining of its skin, primarily under the head, called “ampullae of Lorenzini.” These clusters automatically register an object’s electro-receptive feedback, prompting the shark to taste the object, regardless as to whether or not it is edible. This is why we have seen Great White sharks take “test-tastes” from some pretty strange things: docks, boats, and cages all make the list. Most unfortunately, sharks do sometimes test humans as well, and what may seem like an “itty-bitty bite” to the shark is assuredly not so small, as many shark attack survivors can attest.

This great beast, while certainly more visible than other mysterious oceanic life-forms, remains a curious creature. The Great White shark is seen as one of the more threatening kings of the high seas, but its origins remain somewhat of a mystery. Evolutionary biologists, paleontologists, fossil enthusiasts, and a whole cadre of other professionals and armchair enthusiasts pointed fingers to the Megalodon, or, “megashark,” as the Great White’s ancient ancestor. Up until 2012, the two were considered to be related, based primarily on the only evidence scientists had to work with: a handful of the Megalodon’s teeth.

The prehistoric brute left behind little evidence of its existence, save for its massive, jagged teeth. A shark’s skeletal structure, including the Megalodon,is comprised of cartilage, not bone; thus time and nature have washed away nearly all of this ancient giant’s legacy.

That all changed in 2012, when paleontologists discovered fossilized evidence which debunked the “Megalodon-Great White” familial relationship. The 6.5 billion-year-old fossilized remains of an ancient Mako shark put an end to the century-old debate of the Great White’s origins. While not a complete structure, the ancient Mako’s remains share more characteristics with our current Great White sharks, than those features shared between the Great White and the Megalodon. The fossil revealed a nearly-full jaw and pieces of the spinal column, allowing paleontologists to more accurately compare the features of a modern Great White shark with that of the Mako. An evaluation of several sets of teeth exposed powerful evidence of the relationship between the two species; the Mako shark’s fossilized teeth appear to be a hybrid of its prehistoric ancestor’s fossil record, and the modern Great White. The latter, is seems, evolved from the ancient Mako, not the beastly Megalodon.

If the Great White shark evolved from the Mako, does this mean that the relatively smaller shark poses the same threat to humans? While the Mako are not known to have “human” on the menu, it does not mean that the public can disregard them as a threat. Like many animals, mammals, and cold-blooded creatures, the Mako sharks may attack humans if they pose a threat or invade the sharks’ territories. There is no absolute confirmation that a human will be attacked, but if the Mako shark feels threatened, its instincts will cause it to do what it must to protect itself

As threatening as this cousin of the Great White seems, the “smaller” shark remains even more vulnerable to humans than humans are to them. The Mako’s status as “vulnerable” on the Endangered Species list and subsequent explanations thereof, reveals to the world that the species is being hunted for sport and sale. This can serve as a powerful message, reminding everyone that while the origins and power of the Great White can be traced back to the scrappy Mako shark, humans still pose a great threat to these undersea kings.

By Hayden Freed

Sources

BBC
ABC News
Ocean Portal
Sharks-World
Live Science
How Stuff Works

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