Suriname’s blue poison dart frog (Dendrobates tinctorius azureus).
Also known as the Amazonian poison frog and the Rio Madeira poison frog, the diurnal poison-arrow frog (Adelphobates quinquevittatus) sits in leaf litter on the rainforest floor.
Photograph by Wild Horizons, UIG, Getty Images
The poison frog Atelopus spumarius.
Photograph by Rodrigo Buendia, AFP, Getty Images
The markings on the arrow poison frog Dendrobates leucomelas vary slightly from frog to frog. This species also has a loud trilling call.
Photograph by Auscape, UIG, Getty Images
An employee at the Latoxan SAS laboratory in Valence, France, shows the fangs on an Easter diamondback rattlesnake before extracting the snake’s venom.
Photograph by Balint Porneczi, Bloomberg, Getty Images
Deep in the forests of South America live poison dart frogs that carry around a toxin 200 times more potent than morphine. While it packs a fatal punch for predators, the poison doesn’t much affect the frogs. How?
Their nervous systems have changed over time to fight off the powerful chemicals—an extraordinary example of evolution in action, according to a new study.
“I’ve been wanting to understand how organisms could acquire neurotoxins, [which] requires an animal to reorganize their nervous system,” says study coauthor Rebecca Tarvin, a biologist at the University of Texas at Austin and National Geographic Society grantee.
“It almost seems unlikely that something like that would evolve.”
Getting on Their Nerves
Poison frogs don’t actually make their own poison: They get it from eating mites and ants. Bright colors then warn any predator foolish enough to take a bite.
Predators such as snakes and scorpions, however, use venom, which must enter another animal’s body by physical trauma to properly work. These toxins don’t have to instantly kill: Instead, predators regularly use venom that paralyzes their prey.