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The power of venom -- and how it could one day save your life

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    How does a sea snail catch a fish?
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    I mean, it's a snail, so it's slow,
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    and the fish is not.
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    But yet, this happens.
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    Hidden under the sand is a cone snail.
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    And that orange thing you see
    is kind of like a tongue.
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    We call it a proboscis.
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    It uses that to track and subdue
    this unsuspecting fish.
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    In this predator-prey interaction,
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    these are clearly not
    your garden variety escargots.
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    These are assassins of the sea.
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    And their weapon of choice is venom.
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    Venom, like the venom you find
    in venomous snakes and scorpions,
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    these sea snails, they use their venom
    to subdue fish, worms
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    and other snails.
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    And the venom of these snails,
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    it's not just one thing,
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    it's actually a cocktail
    of toxic molecules
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    that are packaged and delivered
    through a false tooth called a radula.
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    You can think of the radulas
    as hypodermic needles.
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    Now, no need to worry,
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    these snails are practicing
    good needle habits,
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    because each radula is only used once.
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    Now from your own knowledge
    about venomous organisms,
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    and the keep-you-up-at-night
    fish-killing video that I just showed you,
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    you might think that venom
    is dangerous and all bad.
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    Well, yes and no.
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    A more accurate way of thinking of venom
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    is to think of it as both
    a supervillain and a superhero.
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    In my lab, we study the evolution
    of venom in these sea snails
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    as a force for good.
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    Sounds like a stretch,
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    or maybe even snake oil,
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    but actually,
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    while there are snakes involved,
    the product is legit.
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    One reason the venom product
    is so successful
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    is that it transforms a physical warfare
    into a biochemical one.
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    Where usually the predator-prey
    interaction is one of brute force,
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    venom takes it to a molecular scale.
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    And it's not size that matters,
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    but the mixture of your venom arsenal.
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    The chemistry of the toxins
    in your arsenal
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    is what's going to enable David
    to conquer Goliath.
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    And in our scenario,
    David is clearly the snail.
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    Another feature of venom
    that makes it so successful
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    is that the toxins work
    with the precision of a Swiss Army knife.
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    And so these toxins,
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    they come for strongholds
    that help an organism to function.
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    So they target blood, brain and membranes.
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    Whether it's snail venom or snake venom,
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    they each have components
    that can do things
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    like cause your blood to clot,
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    what we call "hemotoxic."
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    Or they cause neurons in your brains
    to not function normally,
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    what we call "neurotoxic."
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    Or they have toxins that will poke holes
    into the membranes of your cells,
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    causing them to rupture
    and, basically, explode,
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    what we call "cytotoxic."
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    Cellular explosion, people.
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    Now, if that is not all powerful
    and all present,
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    nothing is.
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    Now a little about me,
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    and why I'm so obsessed with venom.
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    I grew up in New York City
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    with forced access
    to the Natural History Museum.
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    I say "forced access,"
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    because I'm one of five kids,
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    and my parents used museums
    as a form of childcare.
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    There were two rules:
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    Don't lose anybody
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    and meet Mom and Dad
    at the African elephants
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    at 5.30, when the museum closes.
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    Those totally unsupervised days
    running through the halls of the museum
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    were full of adventure and exploration.
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    And that's how I feel
    when I'm studying venom.
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    It's a scientific adventure.
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    We're boldly exploring this entity
    that connects nature and humanity.
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    Another reason
    that I'm obsessed with venom
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    is because of its duality.
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    When you inject the components
    of a venom arsenal into an organism,
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    it can kill or it can cure.
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    At a molecular level,
    several things can happen.
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    You saw one thing, paralysis in the fish.
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    Now that was happening
    because the toxins in the venom
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    were attacking how the fish's cells
    communicate with each other,
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    preventing it from swimming away.
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    Are there other things
    that I would like to use venom to attack?
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    For sure.
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    And one of those is cancer.
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    Cancer tumors are cells.
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    And like all cells,
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    they communicate with themselves
    and their environment around them.
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    So we would like to find venom components
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    that are very good at disrupting
    how the tumor cells communicate.
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    Similar to how the venom disrupted
    how the fish cells communicated
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    and the fish couldn't swim away.
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    In my lab, we study cancer
    as a channelopathy.
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    What this means is, basically,
    we're looking for venom components
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    that will target channels
    that are overexpressed in tumor cells
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    versus normal cells.
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    The cancer that we're most
    focused on right now
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    is liver cancer.
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    And that's because since the 1980s,
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    the death rate of liver
    cancer has doubled,
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    and it's an emerging threat in the US.
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    In a screen in which we had cervical,
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    neuroblastoma, prostate
    and liver cancer cells,
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    we found a compound from a terebrid snail
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    that seems to attack liver cancer cells,
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    and only liver cancer cells,
    and none of the others that were tested.
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    And then, when we took this compound
    and we injected it into mouse models
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    that were expressing liver cancer cells,
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    it significantly inhibited
    the growth of the tumors.
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    We're not quite sure how this works yet,
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    we're still investigating the mechanism
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    and how we can make
    this compound more effective,
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    so you can't rush out to the pharmacy
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    and order up a killer snail
    liver-cancer therapy treatment.
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    Not yet.
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    Basically, what we think is happening
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    is that the compound is blocking
    a specific channel,
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    prohibiting the transmission
    of a specific chemical
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    that leads to downstream signaling
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    that enables the tumor to multiply
    and draw blood to itself.
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    What we're doing in studying
    the components of venom
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    to find treatments for human
    diseases and disorders,
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    is not new,
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    it's what we call natural
    products drug discovery,
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    and it's been happening for centuries,
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    and in cultures all over the world.
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    Venoms are not only giving us
    cool new compounds,
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    but they're also giving us
    new ways of thinking
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    about how we treat
    human diseases and disorders.
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    And I'll give you three examples.
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    The first is from killer
    snails, of course.
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    And so the first drug from these snails
    that is on the market
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    is called Ziconotide, or prialt,
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    and it's used to treat chronic pain
    in HIV and cancer patients.
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    Prialt is a nonaddictive pain therapy.
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    Three magic words when you think
    about how we're treating pain currently.
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    We're using things that have
    a huge cost of addiction.
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    So think of morphine
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    or think of any of your favorite
    opioid out there.
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    What the snails have done
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    is they've shown us a way to treat pain
    without the addiction,
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    which is huge.
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    The next example comes
    from the Brazilian pit viper.
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    From these snakes, we've derived
    a compound called captopril.
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    Captopril is used to treat
    high blood pressure,
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    and captopril is a breakthrough drug.
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    But not only in and of itself,
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    but because it advanced
    a whole class of drugs,
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    what we know as ACE inhibitors,
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    which are the most commonly [prescribed]
    for treating hypertension
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    and heart failure.
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    The last example is from the Gila monster.
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    And this is a really exciting example
    of understanding the ecology
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    of these organisms,
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    and pairing it with efficient
    drug discovery.
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    And Gila monsters are binge eaters.
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    So when they bite into a large meal,
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    they release things in their venom
    that lower blood sugar.
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    So what's the drug that you think
    we found from the Gila monster?
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    A compound that is used to lower
    the blood sugar in diabetic patients.
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    Now these are three marvelous examples,
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    but we've just scratched the surface.
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    There's so much more venom
    out there for us to study.
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    In fact, we think that 15 percent
    of all the animals on the planet
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    are venomous.
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    And I think this is a low estimate,
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    given the fact that we haven't surveyed
    all the animals on the planet.
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    But nature seems to have found
    something that she likes,
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    and she's repeated it
    over and over and over again,
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    leading to the vast array of animals
    that we see around us
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    and all throughout the tree of life.
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    So whether we're talking
    about my fave, killer snails,
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    or jellyfish,
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    or the larvae of butterflies and moths,
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    or platypus or slow walruses,
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    whether by sea, land or air,
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    you're sure to encounter
    a venomous creature.
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    Remember when I told you
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    that venom can be both
    a superhero and a supervillain,
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    and you doubted me?
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    Mhm.
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    We're in a race to harness
    all of this venom goodness
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    before we lose the vast majority
    of animals on our planet.
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    It's a holistic process.
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    You can't have the therapeutic treatments
    without having the animals.
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    And you can't have the animals
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    without having their ecosystems.
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    So for me and the snails,
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    what it means is
    we have to save the oceans.
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    And because venomous animals
    are found everywhere,
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    we basically have to save the planet.
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    So do it for the venomous animals,
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    if you don't want to do it for yourself.
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    And who knows,
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    some day, snail venom
    might just save your life.
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    Thank you.
Title:
The power of venom -- and how it could one day save your life
Speaker:
Mandë Holford
Description:

more » « less
Video Language:
English
Team:
closed TED
Project:
TEDTalks
Duration:
09:16

English subtitles

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