Don't Panic, But Snakes Still Have The Gene To Grow Legs
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Ophidiophobics beware! If you have an abnormal fear of snakes, you may not like this article. Snakes are slithery, slimy, sneaky, and some might even say they're sinister—but at least they don't have legs, right? Well, snakes actually do possess the gene required for limb growth. Does this mean snakes will start sprouting legs? Who's to say for sure how evolution will continue to shape their reptiles. But we do know that snakes used to have legs, which is how the mostly dormant gene got there in the first place.
Snake Island Is Slithering With Vipers
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Ilha da Queimada Grande, nicknamed Snake Island, is located off the coast of Brazil. It's home to a species of snake found nowhere else: the golden lancehead viper. There are approximately 2,000 to 4,000 vipers on the 430,000-square-meter island, and because their venom is so strong, the Brazilian Navy does not allow civilians to visit. There has never been an official report of a golden lancehead biting a human, but examinations of the snake's hemotoxic venom deem it extremely potent. Other species of lanceheads have caused more deaths than any other type of snake in North and South America.
Boa Constrictors Don't Suffocate Their Prey
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It's long been assumed that boa constrictors kill their prey by suffocating it. But after monitoring the blood flow of rats that were being constricted by snakes, researchers at Dickinson College found that the rodents probably perished due to circulatory arrest. As a snake squeezes, it causes the pressure inside the rat's veins and arteries to skyrocket until the heart can't beat against the added force. The animals pass out quickly, then die.
Key Facts to Know
For a long time, people thought that constrictors killed their prey through suffocation. 0:39
By placing monitors on anesthetized rats, scientists were able to track the rats' blood flow when they were constricted by snakes. 1:26
Research indicates that constrictors cause circulatory arrest in their prey. 1:52
The Tiger Keelback Snake Is Double Trouble
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The tiger keelback snake, also called the yamakagashi, is a venomous snake found in Asia. In addition to having venom that it can inject through its fangs, it also has defensive glands on the back of its neck that can contain poison. The snake doesn't make the poison itself, however—it stores it after eating poison toads. Mother tiger keelback snakes can even transfer some of the toad poison to their offspring, leaving them better able to fend off predators. When threatened, the snakes present these glands so that whatever is trying to eat them might get a mouthful of toxins instead.
Key Facts to Know
Poison can be inhaled, eaten, or absorbed, whereas venom has to be injected into a wound. 0:18
More than 20% of snake bites are "dry" bites, meaning the snake did not inject venom into the victim's bloodstream. 0:30
The tiger keelback snake can be both venomous and poisonous. 1:00
Flatulence As Snake Self-Defense
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When threatened, the hook-nosed snake emits bursts of rumbling air from its cloaca, which is the snake's opening for sex and excretion. This "cloacal popping" is essentially flatulence. Two sets of muscles are used to isolate a compressed air pocket, which can then be released with enough force to propel the snake upward.