WEBVTT - Why Are Komodo Dragons So Deadly?

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<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,

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<v Speaker 1>Lauren bobobam here. The world thought Komodo dragons were mythological

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<v Speaker 1>until about nineteen eleven. During World War One, a plane

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<v Speaker 1>crashed near Komodo Island and the pilots survived to tell

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<v Speaker 1>the world about the animal. He was very lucky to

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<v Speaker 1>tell the tale. Komodo dragons live up to their fierce reputation.

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<v Speaker 1>They will attack and devour a human being unprovoked, and

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<v Speaker 1>they're part of a group of lizards known as monitors.

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<v Speaker 1>And they're the biggest lizards in the world. The largest

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<v Speaker 1>kimodo ever measured was more than ten feet long that's

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<v Speaker 1>three meters, and weighed three hundred and sixty six pounds

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<v Speaker 1>that's about one hundred and sixty six kilos. To get

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<v Speaker 1>a feel for how powerful this creature is, consider that

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<v Speaker 1>when a kimoto weighing just one hundred and twenty pounds

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<v Speaker 1>or fifty five kilos in the London Zoo needs a

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<v Speaker 1>blood test, it takes two people to hold down its tail.

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<v Speaker 1>Compared to the largest on record, the average kimodo is

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<v Speaker 1>about eighty percent of the length but only two thirds

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<v Speaker 1>of the weight. Many scientists think the record animal may

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<v Speaker 1>have eaten a big meal just before weighing in. A

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<v Speaker 1>kimodo can consume about eighty percent of its body weight

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<v Speaker 1>in just twenty minutes. It can swallow huge pieces at

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<v Speaker 1>a time because its skull and jaw are flexible like

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<v Speaker 1>a Snake's Komodo prey includes chicken, wild boar, deer, goats,

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<v Speaker 1>and animals as big as water buffalo. The komodo is

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<v Speaker 1>the only known lizard that will attack prey bigger than itself,

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<v Speaker 1>and about one tenth of the komodo diet is other

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<v Speaker 1>komodo dragons. There aren't many animals that can survive a

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<v Speaker 1>komodo attack. A human and another kimodo are pretty much

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<v Speaker 1>the only ones. This endangered animal, down to fewer than

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<v Speaker 1>three thousand in the wild, is at the top of

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<v Speaker 1>the food chain in its habitat. Okay, What is it

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<v Speaker 1>that makes this lizard such a good predator? Kamodo dragon's

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<v Speaker 1>adult teeth are highly specialized. They're curved into a shape

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<v Speaker 1>like a comma, with a sharp serrated edge along the

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<v Speaker 1>entire curve of the tooth and extra deep ridges on

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<v Speaker 1>the inner curve that's the cutting edge. The lizards use

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<v Speaker 1>a puncture pull motion to tear into prey. The enamel

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<v Speaker 1>on their teeth is relatively thin, but that serrated edge

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<v Speaker 1>has a serious advantage. It's tipped in an iron infused

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<v Speaker 1>coating that strengthens each tooth and keeps it sharp and

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<v Speaker 1>turns it a little bit of a rusty orange. They

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<v Speaker 1>have some sixty teeth in total, each about half an

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<v Speaker 1>inch or a centimeter long, and like other reptiles and

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<v Speaker 1>therapod dinosaurs for that matter, they continually grow replacement teeth

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<v Speaker 1>in case one breaks or wears down. They have up

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<v Speaker 1>to five replacements for each tooth growing at any given time,

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<v Speaker 1>and will start to grow a new one every forty days.

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<v Speaker 1>That's faster tooth replacement than ever any known reptile or dinosaur.

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<v Speaker 1>The real brilliance in the Kmodo system, though, lies in

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<v Speaker 1>the guarantee of a meal. Their byte strength is a

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<v Speaker 1>bit weak compared with other large reptilian predators, and its

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<v Speaker 1>attack doesn't usually kill its prey out right, But a

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<v Speaker 1>bitten animal will almost always die within a few hours

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<v Speaker 1>or at most a few days. The komodo can wait patiently,

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<v Speaker 1>following it for miles in a leisurely fashion, and then

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<v Speaker 1>locate the dead animal by its smell. Like most lizards

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<v Speaker 1>and snakes, a komodo dragons have a very good sense

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<v Speaker 1>of smell, but it's not the kind of smell most

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<v Speaker 1>of us are familiar with. Like a snake, a kimodo

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<v Speaker 1>smells by collecting air with its forked tongue and then

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<v Speaker 1>depositing that air on scent receptors on the roof of

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<v Speaker 1>its mouth. Using this method, it can detect a dead

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<v Speaker 1>animal up to about five miles away that's eight kilometers.

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<v Speaker 1>Why exactly an animal usually dies after the fact has

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<v Speaker 1>been a object of some debate. Until the past decade

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<v Speaker 1>or so, scientists thought that it was a komodo dragon's

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<v Speaker 1>oral bacteria that killed its prey within days after an attack.

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<v Speaker 1>It's a decent explanation. A bite wounds from all kinds

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<v Speaker 1>of animals, including humans, can transfer bacteria into the bloodstream,

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<v Speaker 1>causing infection, sepsis, and organ shut down throughout the body.

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<v Speaker 1>It was also traditionally thought that most reptiles don't produce venom.

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<v Speaker 1>Venom is a toxin that's secreted by special glands and

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<v Speaker 1>injected into an animal by a bite or sting. We

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<v Speaker 1>knew that lots of snakes are venomous, but only two lizards,

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<v Speaker 1>the Gila monster and the Mexican bearded lizard, were known

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<v Speaker 1>to harry venom, but beginning in the two thousands, research

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<v Speaker 1>has proven otherwise. In two thousand and five, scientists concluded

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<v Speaker 1>the komodo dragons and actually all monitor lizards as well

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<v Speaker 1>as iguanas, produce venom. The researchers started looking specifically for

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<v Speaker 1>venom in komodo because they believed it was unlikely that

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<v Speaker 1>a bacterial infection could kill an animal in as little

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<v Speaker 1>as a day or two. They found venom in komodo saliva.

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<v Speaker 1>In two thousand and nine, further research involving magnetic resonance

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<v Speaker 1>imaging of a preserved Kmodo dragon head discovered a venom

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<v Speaker 1>gland and ducks with openings between those sharp teeth. The

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<v Speaker 1>researchers noted compounds in the venom that induced muscle cramping, hypothermia,

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<v Speaker 1>and low blood pressure, a dangerous combination, especially since the

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<v Speaker 1>venom also contains anticoagulants. Basically, without serious intervention, most animals

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<v Speaker 1>bitten by a komodo will go into shock and bleed out.

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<v Speaker 1>It's not as potent as a cobra venom, which can

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<v Speaker 1>kill in minutes but still undeniably fatal. In the case

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<v Speaker 1>of large animals like water buffalo, for which the amount

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<v Speaker 1>of venom transferred during a couple of bytes might not

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<v Speaker 1>matter much. The komodo dragon's aforementioned mouth bacteria might help

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<v Speaker 1>finish the prey off. The deepness of the bites might

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<v Speaker 1>allow environmental bacteria to enter the wounds. Because kmodo dragons

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<v Speaker 1>don't get sick from the bacteria in their own mouths,

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<v Speaker 1>it's thought the components of their blood might have applications

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<v Speaker 1>in medical research. Back in twenty seventeen, a team of

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<v Speaker 1>researchers found a promising peptide in komodo blood and used

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<v Speaker 1>it as inspiration to create a synthetic peptide that's antibacterial.

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<v Speaker 1>It both weakens bacteria membranes, making them less able to survive,

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<v Speaker 1>and it prevents them from forming up into tough biofilms,

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<v Speaker 1>which could help us fight antibiotic resistant diseases. And compounds

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<v Speaker 1>found in various venoms have been used to create treatments

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<v Speaker 1>for everything from high blood pressure to diabetes. Here's hoping

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<v Speaker 1>that this and other research and komodo dragons fascinating adaptations

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<v Speaker 1>might lead to lots of real world applications. Today's episode

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<v Speaker 1>is based on the article Arkmoto Dragon's mouths Deadlier than

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<v Speaker 1>Cobra's venom on how stuffworks dot Com, written by Julia Layton.

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<v Speaker 1>Brain Stuff is production by Heart Radio in partnership with

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<v Speaker 1>how stuffworks dot Com and is produced by Tyler klang A.

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