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during the vietnam war officer jeremiah
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denton was captured a few months later
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he was forced to participate in a
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televised interview while answering
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questions denton managed to send a
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secret message he did it using his eyes
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it seems humans can do something like
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that thanks to our high intelligence
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turns out animals can also use their
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body parts in unexpected ways
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frogs swallow food with their eyes
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i'm serious if you've seen a frog eating
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at least once you may have noticed it
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closes its eyes when swallowing well why
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not maybe the food is very good turned
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out that taste has nothing to do with it
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during swallowing the frog's eyes
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actually retract down toward the
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esophagus imagine this would happen to
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people it'd be like in a horror movie
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but frogs just have to use eyes for this
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unlikely purpose apparently the eyes
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retracted into the head help push the
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prey down into the esophagus and if the
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frog loses this weird ability it'll have
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to take 74 percent more swallows to
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handle a common cricket that certainly
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sounds weird frogs are probably a little
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insecure since they can't swallow food
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like all other animals well you know
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this is not a trick that would make you
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popular at parties also most frogs don't
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have teeth and in some of them who do
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you can only find them on the upper jaw
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and they are totally useless seems like
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when evolution was giving out teeth the
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frogs were distracted and took what was
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left or maybe they got them from someone
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else to get to the bottom of things you
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need to look at the development of teeth
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in different species turns out they all
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evolved from fish scales yes i also
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imagined how scales got into the mouth
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of some ancient fish and it's like hmm
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it's much better this way but the actual
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story was a little different some fish
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have skeletons made entirely of
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cartilage they also have small spiny
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scales embedded in the skin called
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dermal denticles these bear a striking
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resemblance to teeth and not only from
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the outside they have the same cellular
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composition the same cells play a key
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role in the development of teeth and
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mammals do you feel the connection over
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time the scales of ancient fish evolved
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into the teeth we now have evolution
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you're weird now here's a fact for you
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the skin of some sharks is covered with
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dermal tentacles that is with the teeth
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let me give you a second to imagine this
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shot from a horror movie apparently
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frogs also had teeth but they
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disappeared about 200 million years ago
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perhaps frog's diet has changed or maybe
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it's all about the tongue they use to
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catch their prey it turned out to be so
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convenient that evolution decided frogs
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don't need teeth anymore but this is
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objectively not the best option not only
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because an animal without teeth becomes
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more vulnerable to predators and cannot
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defend itself in the traditional way
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there's also an issue with digestion
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food that has not been chewed can emerge
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out of the body of a predator alive on
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the other side in one of my videos i've
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already mentioned the bombardier beetles
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which crawl out alive after passing
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through the frog's gut the bromine blind
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snake a small snake that looks more like
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a large worm can do the same thing
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scientists were very surprised when they
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accidentally discovered this they just
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needed a rock to prop open the lab door
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and beneath the rock there was a toad
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with a snake wriggling out of the toad's
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rear okay technically it doesn't really
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count as using a body part for a
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different purpose after all you need it
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in order to remove various substances
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from the body the fact that these
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substances are alive and move by
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themselves is a minor detail so let's
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better take a look at the turtles many
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animals have special tricks that allow
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them to survive during the frost usually
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the main issue is cold but if you live
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in a pond you also have to deal with
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lack of oxygen painted turtles breathe
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with their lungs however during frost
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they simply cannot get to the surface
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and take a breath because of ice they
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lower their body temperature and slow
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their metabolism by 95 to survive the
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cold it's kind of like hibernation in
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bears but the turtles start breathing
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through their butts this process is
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called clonical respiration and oxygen
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is absorbed through the skin at the same
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spot i'm suffocating i'm suffocating
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steve get off the stone
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that's better in fact skin breathing is
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very rare in reptiles they can usually
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only breathe through the mouth since
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it's impossible to inhale through the
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scales they're too hard and don't let in
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enough oxygen amphibians and fish are
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much luckier actually even people can
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breathe through their skin though for us
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cutaneous respiration accounts for only
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one to two percent of oxygen uptake you
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can't use it as a main source of oxygen
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meanwhile cutaneous respiration in
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hellbenders accounts for more than 90 of
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their breathing that is their skin
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absorbs oxygen and removes carbon
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dioxide imagine how cool it would be if
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humans could do that too especially when
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you have a stuffy nose but let's be
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honest there are many downsides to this
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type of breathing we would not only have
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to constantly keep our skin moist or
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even smear ourselves with special mucus
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the air we absorb would be dirty right
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now there are many microorganisms
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various microbes dust and other
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unpleasant stuff floating around us and
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you definitely not want it to end up in
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your body but as long as we breathe with
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our lungs we can filter the air
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evolution has given us four stages of
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purification small hairs in the nose
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mucous membrane epithelium in the
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bronchi and trachea and finally
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pulmonary surfactant this is the
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substance that covers our lungs from the
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inside each filter the air passes
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through cleans it increasingly well
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large particles are stopped at the very
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beginning small ones at the very end as
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a result we inhale relatively clean and
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safe air you can hardly achieve
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something like this if you breathe with
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your skin however it's possible to not
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only breathe but also drink through the
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skin neat thorny devil a lizard that
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lives in the australian deserts it's
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small charming and terribly thorny and
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it also has some issues with drinking
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not only because it's really hard to get
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water in the desert if you put a bowl of
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water in front of the thorny devil it'll
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probably never use it for an intended
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purpose just because it can't i have no
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idea how this happened but the mouth of
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the thorny devil is good only for eating
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do you know these dogs that attack the
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water well that's what it would look
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like maybe evolution got too carried
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away creating all these thorns and
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forgot to give the animal the ability to
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drink whatever the reason may be the
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thorny devil found a way out and began
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to drink through its feet once on wet
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sand or in a puddle the lizard absorbs
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the liquid like a sponge the same thing
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happens in the morning hours when dew
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forms the skin of the thorny devil is
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covered in microscopic grooves that
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create a network of drinking straws they
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can take up water from any part of the
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body through capillary action whereby
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water is drawn along a channel even
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against the pull of gravity and then it
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travels right into the mouth and then i
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thought if these lizards are so good at
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absorbing water maybe some natives use
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them as flasks well you know like an
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australian water holding frog which
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stores water in itself but it looks like
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this trick won't work with a thorny
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devil it's too thorny however people
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have found alternative ways to get water
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with the help of animals about 70 of the
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australian continent is covered by
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deserts or semi-arid land aboriginal
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people needed to know where to find
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water just to survive but they didn't
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just dig wells they also used terrain
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birds vegetation and animals as markers
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for water for example they followed
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dingoes or birds to lakes while ants led
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them to groundwater what a nice idea the
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important thing is that animals do not
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realize what's going on and don't lead
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us to a wrong place this is not an
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unlikely scenario for example baboons
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know exactly where the water sources are
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but they're not going to share this
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information so people in africa came up
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with a trick they feed the baboons with
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something salty then wait until they get
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thirsty and then all you have to do is
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follow the animal to the reservoir here
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you go you've done great and you're no
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longer thirsty although i would not be
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surprised if even in this situation
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baboons learn to deceive people they are
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natural born liars scientists even
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believe humans inherited the ability to
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lie from primates you know a kind of
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hereditary skill like with harry potter
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and flying on a broomstick chimps who
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find something tasty sometimes pretend
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that they didn't notice the food not to
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alert their relatives and not to lose
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their share is that smart of course
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especially for the animal but chimps
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don't stop there sometimes a rival chimp
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walks past a pretender then hides behind
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a tree and looks out to check if the
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pretender has food go on i'll catch up
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with you i just need to tie my shoe sure
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wait a minute you don't wear shoes
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primates need lying to survive yes in
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terms of human morality this doesn't
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exactly look nice but when you have to
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choose between starvation and deception
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well every animal strives to survive
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however don't think chimps don't care
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about liars if one of them is caught
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cheating he won't avoid punishment in
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general it's just like in a human world
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see you later