[MUSIC]
Alex I'll take "Potent Potables" for $200 please.
I may move slow, but my venom can kill you in minutes.
Joe
What is a cone snail!
That is correct.
I'll take "Potent Potables" for $400 please Alex.
Whether it’s Mortal Kombat or my venomous tail, play against me and you could see a “fatality”.
Joe again.
What is a scorpion!
Yes.
"Potent Potables" for $600 Alex.
[OPEN]
Only a few of nature’s toxic avengers earn the title of “venomous.”
If a toxin has to be ingested, inhaled, or absorbed, we call that animal poisonous, like
these frogs.
But venomous animals deliver it direct, usually into a wound.
Biting, stinging, stabbing, that sort of thing.
We find venom all over the animal kingdom, and there’s as many different venoms as
there are venomous species.
Animals with spines and stingers often use venom for defense.
Animals with toxic mouthparts or tentacles tend to use their venom to hunt.
Others use venom to eat or even to fight during mating season… just when you thought the
platypus couldn’t get any weirder.
So what’s the most venomous animal?
It’s tough to say.
Scientists usually rank venoms using a number called the “LD50”, the dose it takes to
turn half of test animals from alive to… no longer alive.
The lower the LD50 the deadlier the venom.
But most venoms didn’t evolve to target lab mice, so that number doesn’t always
tell the whole story.
When we add in factors like how often people are bitten or stung and how many actual deaths
that animal causes… the winner for “deadliest” is clear.
Why’d it have to be snakes?
Venomous snakes make some of nature’s most deadly and complex chemical cocktails.
They manufacture that venom using modified saliva glands, and deliver it using hypodermic
needles disguised as teeth.
On paper, a soft, ectothermic noodle isn’t the ideal predator, but with venom in their
arsenal, snakes don’t have to outrun or fight their prey.
They just paralyze it with neurotoxins, or let it bleed to death from the inside by injecting
hemotoxins.
Who needs legs when you’ve got chemistry?
When toxinologist Bryan Fry mapped snake venom genes onto an evolutionary tree, he found
that snakes branched off from lizards about 100 million years ago, but their venom was
even older.
Venom is so biologically expensive that many modern snakes have stopped making it, but
the ancestor of all snakes was venomous.
The earliest venom proteins were borrowed from other parts of the body, where they did
normal jobs, like control blood pressure or how nerves work.
If they were present in saliva, and happened to kill prey faster, that species gained an
advantage.
As venoms became more toxic, evolution isolated them in the mouth so snakes wouldn’t poison
themselves, and they developed sophisticated delivery methods.
Venom genes across the animal kingdom are some of the fastest-evolving genes we know
of.
Snakes are constantly changing up their formula to stay one bite ahead of their prey developing
resistance.
Even though a cobra can take down an elephant, to a honey badger, it looks like dinner, and
several other snake-eating animals have figured out venom immunity.
Like honey badgers, mongooses and hedgehogs have tiny mutations in the switches that control
muscle contraction, so venoms that cause paralysis don’t work on them.
And the opossum is so awesome that one ingredient from its blood can neutralize a wide variety
of snake venoms.
Scientists are studying it as a possible universal anti-venom.
Today, antivenoms are made by injecting nonlethal doses of venom into a large animal.
Its immune system goes to work dispatching antibodies to inactivate the venom, the antibodies
are purified from the blood, and we have an anti-venom cocktail ready for some unlucky
human.
But a few people think we can train our own immune systems to fight venom.
Self-immunizers regularly inject small amounts of venom into their own body, hopefully not
enough to kill them, but enough to get their antibody factories going.
I shouldn’t have to say this, but DO NOT try this at home.
SI-ing sounds like a ticket to the Darwin Awards if you ask me, but still, those who
do it claim they can take lethal doses of venom and walk away.
Of all venomous animals, we seem to have a special interest in snakes.
Brain scans have shown that we can detect snakes before we consciously see them, there’s
even special neurons in primate brains that only respond to images of snakes.
The evolutionary pressure of not becoming dinner for a hungry snake favored primates
with more complex vision.
More complex vision required larger, more complex brains, and larger more complex brains
are what set our ancestors down the path of becoming us.
Anthropologist Lynne Isbell calls this the “Snake Detection Theory” of primate evolution.
It’s certainly only part of the story of our big brains, but to come down from the
trees and bite into a world of knowledge, maybe we just needed a little help from a
snake.
Stay curious.