As many of us know from the viral video, the honey badger doesn't care about anything. It forgoes concern of bee stings and venomous snake bites for the sake of grabbing a snack.
University of Minnesota grad student Danielle Drabeck wondered what made this hungry animal immune to bites that would kill most other animals. She decided to investigate on a molecular level—all she needed was a sample. Honey badgers are not exactly common in the United States (wild badgers live in Africa, the Middle East, and India), so Drabeck enlisted the help of biologist Sharon Jansa and biochemist Antony Dean. The team acquired blood samples from zoos in San Diego and Fort Wayne, Indiana.
The scientists studied the blood to find out why the mammal was venom-resistant, keeping in mind that this could also help make for more effective anti-venom for humans.
Cobra venom has molecules called alpha-neurotoxin that paralyze the victims' breathing muscles. The alpha-neurotoxins attack muscle cells' nicotinic acetylcholine receptors and block signals from the nervous system that try to keep respiration working.
After sequencing the honey badger's DNA, Drabeck found that its nicotinic acetylcholine receptor has mutated to prevent this from happening. This mutation has occurred independently in four animals: honey badgers, mongooses, hedgehogs, and pigs. Pigs were a surprising development; in the past, scientists had assumed pigs could survive snake bites only because of their thick skin and abundance of fat.
Because of this, predator and prey have been locked in an evolutionary arms race—venomous snakes are getting more potent bites, and immune animals are upping their defenses.
But why go after poisonous snakes instead of avoiding them?
“Snakes,” says Drabeck in the study, “are an excellent source of meat.” Evolving to be immune to snakes means that the badgers are one of the few animals alive that can prey on venomous snakes. There's less competition and snakes are much easier to catch when their main defense is rendered useless.
Not that honey badgers care about any of that.