Is anyone there?

This is Jake Roper from Outpost 31.

The lab is destroyed.

I need immediate support.

Please come back.

Vsauce, I’m Jake and I’m glad I’m not the only one who made it out alive.

I think the parasite is destroyed or at the very least will freeze out here in the cold.

I’ve never seen anything like it.

Able to completely take over the form of another, of a person.

Parasites...

What makes the one we are dealing with or...were dealing with so unique is that humans in general

appear to be less prone to being manipulated by parasites but, in Kathleen McAuliffe’s

book This is Your Brain on Parasites she gives an interesting example: “If a cold germ

makes you cough, is that your body trying to clear the infection from your lungs or

the parasite tickling the back of your throat so that you’ll spread the germ?”

It’s the manipulation hypothesis: when a parasite purposefully changes the behavior

of the host.

And it does this, generally, to increase its chances of transmission.

To spread.

An example that can be seen in humans is the Guinea Worm which gets into your body when

you drink stagnant water

In that water there might be water fleas which carry the Guinea Worm larvae (larvie).

Our stomach acid dissolves the flea but not the larvae, the parasite.

It grows into worms that push inside the intestinal walls and procreate in your abdominal muscles.

The male worms die, get absorbed by your body but the female grows.

And grows until it is about a meter long.

It spreads through your connective tissue, making its way to a lower extremity...your

foot, calf, etc.

And it stays there for a year and you, the host, have no idea.

By this point the female is bursting with larvae of its own so it releases an acid that

makes your skin bubble and blister.

It burns so your body’s reaction is to dip the blistered area in water, but in doing

so hundreds of thousands of larvae are pushed out of the female worm’s mouth and into

the water...exactly where the larvae need to be to repeat this cycle.

And then there are parasites that, unlike the Guinea worm, don’t keep themselves hidden

inside you, instead, like in the case of the parasitic flatworm the green-banded broodsac,

they change your appearance.

A snail unknowingly eats bird droppings infested with broodsac eggs.

The eggs hatch inside the snail, forming long tubes that spread into the snail’s brain

and tentacles, it’s eye stalks.

It fills the stalks up so fully that it stretches the walls so thin that you can see the parasite

through it, colorful and pulsating.

And those pulsating bands are broodsac larvae.

Because the parasite has pretty much taken over the snail’s eyes, its vision is impaired,

it starts spending much more time out in the sun, out in the open because it can’t judge

if it is in darkness or in light.

Birds see the pulsing eyestalks and think they are caterpillar grubs.

The bird swoops down and then flies off with a belly full of broodsac larvae which then

reproduce in the bird and the eggs come out in the bird’s droppings.

Rinse and repeat.

(Sip and spit)

It is a form of aggressive mimicry, where the parasite resembles the food of the predator

it wants as a host.

they use the host as a kind of living taxi, riding in the foreign body to get from point

a to point b.

They are transient, to continue their life cycle they need to find a new...home

But there are parasites that are more insidious.

They don’t use the host as transport or use the host’s bodily responses against

them, instead they take over the mind.

Ampulex compressa, the jewel wasp.

It stings a cockroach in the thorax, temporarily paralyzing it.

Quickly it moves to the roach’s head where it precisely stings and injects a poison that

blocks the neural area for decision making.

Taking away the cockroaches free will.

The wasp then bites off the antennae of the roach, slurping out fluid from the open stems

and leads the host to the Wasp’s burrow and lays an egg on its abdomen.

The wasp then closes off the burrow, trapping the resting roach and egg inside.

After 3 days, the egg hatches and begins to feed on the still living cockroach.

What started as an ectoparasite, external, becomes an endoparasite, internal, the larva

eats its way inside of it...slowly devouring the roach’s organs in such a way that the

cockroach will stay alive for as long as possible.

After cocooning itself inside the roach it emerges, fully grown.

And the host has finally died.

And there are many other kinds of parasites...like cordycepts that sprout out of an ant’s head

and rains pours down onto other ants.

Ones that take over the tongue of fish.

There’s even one that an estimated half the human population has that you can get

from cat feces.

More than 1400 parasites prey on humans, and those are the only ones we know about.

With some you don’t even know the parasite is in you.

It wants to survive so it’s best tactic is to be hidden.

Or it takes you over completely.

Which brings us to a parasite that most closely resembles the one we are currently dealing

with, Sacculina.

Sacculina is a parasite that infects crabs.

It finds a soft spot on the joints of the crab, uses a sharp part of its body and injects

itself inside.

It then spreads throughout the crab, like roots in the ground.

Creeping into organs, the nervous system and the crab’s eye stalks.

It even grows a sac on the underside of the crab where the crab’s eggs would be are

now the reproductive part of the parasite.

The crab stops malting, growing, it becomes sterilized.

It’s purpose now to continue the lifecycle of this parasite.

It loses its free will.

It becomes a suit of armor, a robot being controlled by an operator.

From the outside it looks the same, it even generally acts the same, but inside…

Is the cockroach, the crab, even the snail aware of the actions that are happening?

Does it know that it no longer has free will?

Just like the bacteria in our gut, which is more plentiful than the cells in our own body,

can dictate our diets without us being conscious of it...maybe a parasite could do the same.

The difference being that the bacteria is in a symbiotic relationship with us, it’s

mutually beneficial, and in a parasitic relationship...it is not really a benefit to the host however

parasites are important to the overall ecosystem.

And when we zoom out and think of this ecosystem, it is easy to understand the philosophical

idea of our relationship with the planet we are all currently on.

What started as symbiotic relationship with us and Earth could be seen as becoming parasitic.

I mean, even pregnancy could be thought of as parasitism.

Huh, I don’t know.

My mind is all over the place.

I think I’ve been out here too long.

I don’t actually know how long.

To me, the scariest part is...how do you know your actions are your own?

If you did have a parasite in you, and it was a successful organism, would you know

it was there?

Are these words I’m saying even mine?

How do I know that you aren’t infected?

The parasite we uncovered at the lab could become anyone, any living thing.

I don’t think I am different but can I ever be sure?

How would you know your mind is lying?

Maybe we should just sit here

and wait.

This is emergency control we received your SOS please give us your exact coordinates

for rescue.

Just and watch the fire to die.

Again this is emergency control please...

And, as always, thanks for watching.