Name: 20 MILLION Year-Old Spider!! Unweaving Spider Silk
Uploaded: 2018-04-03T04:12:20.000Z
Duration: 7 min 52 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Think about this: Wherever you're sitting right now, chances are there's a spider nearby.

And you should be excited about that, because spider silk is awesome.

Spiders manufacture something stronger, stretchier, or stickier than just about anything humans have engineered.

A thread of spider silk is nearly invisible, which is why you've probably walked through it with your face.

Yet when it comes to strength, some spider silk fibers rival steel and Kevlar.

Imagine this: A silk cord about the diameter of a garden hose could hold up a passenger jet.

So how does such a tiny animal weave such an amazing material using nothing but its rear end?

I wanted to find out, so I went to the American Museum of Natural History to meet Dr. Cheryl Hayashi,

who's maybe the world's #1 expert in the science of spider silk.

Everybody knows that spiders make silk, but I don't think most people realize just how

There's over 46,000 described species of spiders – and most spiders make four, five,

So this is Nephila clavipes, the golden orb-weaver, and she can make seven different types of silk.

Well, some people don't think it's a tiny little body…

It's not the smallest spider I've ever seen!

When you look at the golden orb weaver's trademark web, you're actually looking at

There's the dragline silk: The spider drags it behind like a climber's safety rope.

There's one silk to guide the web's construction.

The spiral that traps prey, is actually a mix of two more silks: A stretchy silk covered

There's a cement-like silk to attach the web to whatever it's hanging on.

Seven different silks, all made by one spider.

Spider silk is made of proteins, and the dominant proteins inside a silk fiber are these specialized

category of proteins called spidroins, which stands for spider fibroins, that are unique to spiders.

Inside the body, all of the silk glands have liquid protein in them.

So it's liquid protein, and when I dissect a spider and I take out a silk gland, and

I break the gland open, it has the consistency of honey!

It's a viscous, gooey substance that's in there.

And it's highly-concentrated silk protein.

It kind of makes you wonder what an anatomically correct Spider-Man would look like.

The raw ingredients for every protein chain are twenty amino acids, and the recipes for

The order of amino acids in these chains determine what a protein looks like, and what it will do.

And spider silk proteins are built in a very special way.

Imagine a silk molecule like a long train, made up of different boxcars.

Inside each type of boxcar is a string of amino acids.

In any one type of silk, we see the same boxcars over and over all the way along the train.

This unique pattern is what makes each silk so specialized.

Spiders have cooked up some equally specialized ways to use these silks.

Like the trapdoor spider, which weaves a camouflaged shelter from silk.

The ogre spider, that it casts out a silk net like a fisherman.

Or the redback spider, who weaves a trap in the form of sticky spring-loaded snares.

Other spiders shoot venom-laced deadly silly string silk.

Small spiders can even ride the winds on silk sails, a trick called “ballooning” that

To find the origins of spider silk, we have to go a long way back.

This is fossil amber, it's from a Burmese deposit, and there's a spider in here, and

Do you want to touch a 100-million-year-old spider?

I'm holding a piece of the world from 100 million years ago, and there's a spider

in there that was already making silk like spiders do today?

Here's another fossil spider, this one's not quite as old: only 20 million years old.

It knew that we would find it one day, and it was like, “I'm gonna give them a really good pose.

But Dr. Hayashi doesn't just study how spiders evolved and how they make silk.

She also studies its mechanical properties.

If you're picturing her pulling on spider silk with tiny tweezers, you're not far off.

This is one strand of dragline silk, that what's on this card.

She unweaves these single silk strands by hand, and mounts them into a special machine

to test how much pulling it can take before it breaks.

And you can see there's a fiber connecting that.

So the only thing connecting this part of the machine: this clamp to this clamp, is the silk fiber.

We're going to break this spider silk so good.

Weight for weight, almost nothing we humans have invented is as strong, as stretchy, or

absorbs energy as well as some spider silks.

So naturally, we're trying to figure out how to manufacture and weave this stuff for ourselves.

The approach is you take the spider silk gene, and you move that silk gene into another organism

such as bacteria, a plant, a silk worm, or even goats.

So in the goat, it actually comes out, it's expressed in the mammary gland.