Animals Can Be Born With Two Heads

You might want to sit down for this one... two-headed sharks are very much a thing. But before you cancel your holiday beach trip for fear of a JAWS-style attack times two, know that the likelihood of a two-headed shark birth is 0.13 percent, and if the shark actually survives, its life will almost surely be brief. Quick—re-book those flights to Florida!

The biological phenomena of animals being born with two heads is called dicephalia. Although rare, two-headed animals have been documented since the 1800s. A producer named Todd Ray actually has the Guinness World Record for the largest collection of two-headed animals, including a two-headed goat and a two-headed albino hog-nosed snake. So what causes this defect—could it be man-made?

In an October 2016 study on lab-grown two-headed shark embryos, Spanish researchers determined that the sharks' dicephalia was likely caused by a genetic mutation, or "nature's fluke," versus a reaction to chemicals in the lab. Wild sharks, however, are affected by a number of variables. According to National Geographic, scientists postulate that naturally-occurring dicephalia can be caused by "viral infections, metabolic disorders, pollution, or a dwindling gene pool due to overfishing [causing inbreeding]." So keep your beach plans, but maybe watch the news before taking a dip in ocean...

Learn more about dicephalia in nature, as well as other crazy animal facts and mutations in the following videos.

Two-Headed Sharks And Other Crazy Anomalies

Two-headed sharks are definitely a thing! Learn more about dicephalia and other animal anomalies with DNews.

Animal Facts That Will Make You Feel Weird

Zebras don't have black stripes—they're black with white stripes. BOOM.

Written by Curiosity Staff November 19, 2016

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