11/14/2014

Horns, Claws, and Teeth: The Animal Weapons Arms Race

16:53 minutes

Animals have developed horns, claws, and teeth to defend themselves, but what is the advantage of a bulky crab claw that weighs half as much as the entire animal, or 14-foot-wide antlers on the extinct Irish Elk that stood seven feet tall? Doug Emlen, a biologist and author of Animal Weapons, describes the evolutionary arms race that pushes these animal weapons to the extreme. (Read an excerpt from the book here.)

  • Narwhal and walrus. Illustration by David J. Tuss

  • Saber-toothed cats probably leapt from trees onto unsuspecting mastodon calves. Illustration by David J. Tuss

  • Battling rhinoceros beetles. Illustration by David J. Tuss

  • The fangtooth, umbrella eel, and anglerfish all have massive jaws and teeth. Illustration by David J. Tuss

  • Irish elk had the largest antlers of any deer, shown here alongside a fallow deer buck. Illustration by David J. Tuss

  • Porcupine spines are effective defensive weapons. Illustration by David J. Tuss

  • New Guinean moose fly with “antlers.” Illustration by David J. Tuss

  • Ball-rolling dung beetles fight in scrambles, rather than duels. Illustration by David J. Tuss

  • Fighting harlequin beetles. Illustration by David J. Tuss

Segment Guests

Douglas J. Emlen

Douglas J. Emlen is a professor of biology at the University of Montana and author of Animal Weapons: The Evolution of Battle (Holt, 2014).

More From Guest

Related Links

Meet the Producer

About Alexa Lim

Alexa Lim was a senior producer for Science Friday. Her favorite stories involve space, sound, and strange animal discoveries.

Explore More

From Antlers to Tusks: Our Obsession With Extreme Animal Weapons

An excerpt from "Animal Weapons."

Read More