Why 8 Eyes Are Better Than 2 (…If You're a Spider 🕷) (2)
Alex applies some melted wax
and mounts a little stick hat which he'll remove later.
Next the spider holds onto a little ball.
Alex can track the ball's motion
to measure how the spider turns and moves
while looking into the eye tracking microscope.
- What we have here is a special camera
that allows us to pick up light
that's reflected off the retinas.
So what we're left with is what the spider is viewing
and where they are actually looking.
- So just like the doctor like looks in my eye
can see my retina and stuff when I go get an eye exam,
you're doing the same thing here?
- Yeah, exactly.
And as the spider gets fatigued or less interested
you see this exploratory movement where it's looking around
but once-- - So it's just getting bored.
- It's getting bored. (Joe laughs)
But when the cube moves again the spider gets interested
and tracks it. - And they're doing this
all by moving their eyes inside their head.
- Inside their head yep.
- And so sometimes I even see the eyes
seem to almost point different directions for a minute.
Like they come apart there and then they're back together.
- [Alex] If they're really interested in something
like a cube moving in front of them,
they bring the retinas together
to get a better view of it.
- We should give them something
really interesting to look at,
like some YouTube videos.
- Yeah, definitely.
- [Joe] I couldn't think of anything better to watch.
And our good friends from Deep Look,
let's see if spiders like Deep Look.
- [Alex] Yeah, let's check it out.
- [Joe] Okays so the fly's moving
and the retinas look right at it.
What must be hungry.
- [Alex] Oh yeah.
(Joe laughs)
- This might be the first time
a spider has ever watched a YouTube video,
except for the one that's right behind you right now.
Getting up close and personal with my spider friends
has really made me wonder why do jumping spiders
need a visual system that's this complicated?
I mean their world is so small.
But these tiny feats of biology and physics
have allowed them to interact with that world,
with their prey, with their habitat,
even with each other, in some super interesting ways.
- Maybe if you were thinking about sort of
a classical representation of a spider,
you imagine a large web,
and insects flying in and getting trapped,
and the spider running over
and detecting the vibrations in their web.
But jumping spiders are a lot more like cat-like predators.
So they walk around, they stalk prey, they pounce on it.
- Their visual system also comes in handy
during mating displays, which are pretty impressive.
When a male spider approaches a female (accordion music)
trying to mate he never knows if he's gonna end up
getting eaten or getting lucky.
So many jumping spiders perform elaborate dances
as a way to attract female attention from a safe distance.
Researchers have used the spider eye tracking machine
to see where females look during these dances
and which parts they find most attractive.
In mammal eyes and jumping spider eyes
nature's solved the same problem
using totally different hardware.
I think that's pretty cool considering that we're separated
by hundreds of millions of years of evolution.
And this is just one family of spiders.
Spider eyes come in lots of different numbers,
arrangements, shapes, and sizes.
Each combination is perfectly suited
to a unique way of living spider life.
But jumping spider eyes with those highly adapted telescopes
and powerful motion sensors,
they're unique not just among their eight legged cousins
but really all animals.
Now that I've learned how they see,
I think these guys might have the best eyes
like of all the eyes.
It's just one example of how nature can fit
some pretty surprising things in really small packages.
I mean literally right under our noses.
They are adorable and awesome
and I hope everyone else appreciates them a little bit more.
Maybe like me,
you've fallen in love with the cats of the spider world.
Stay curious.
Ahoy matey.
I'm a pirate.
The newest show over on PBS Origins
will take you on an enlightening voyage
through the pirate history that you've been missing.
It's called "Rogue History".
It unravels the historical myths, unearthed lost narratives,
and champions some unsung heroes.
It's basically the pirate history you were never told.
Hit that link down in description and explore it now
or walk the plank.
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to tell you about our Patreon page.
We rely on the support from our audience,
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to submit a dad joke and have it read by me,
at connoisseur of fatherly humor.
No jumping.
I see that.
I see that.
Stop it!
Don't jump outta the box.
He's like, let me out.
You're doing great just.
Don't you?
Don't you little cutie pie?
You have the best eyes?
Are they the best little eyes?
Hello, I'm over here. Are you sleepy?
