Name: 【TED-Ed】The hidden worlds within natural history museums - Joshua Drew
Uploaded: 2014-12-26T03:09:01.000Z
Duration: 4 min 27 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...

When you think of natural history museums,

Adverbs of manner

you probably picture exhibits  filled with ancient lifeless things,

which only includes  about 1% of a museum's collection,

there are hidden laboratories  where scientific breakthroughs are made.

and on the floors  the elevators won't take you to,

This maze of halls and laboratories  is a scientific sanctuary

that houses a seemingly  endless variety of specimens.

Here, researchers work to unravel  mysteries of evolution,

One museum alone  may have millions of specimens.

The American Museum of Natural History in New York City

Scientists have logged exactly where and when it was found

and used various dating techniques  to pinpoint when it originated.

Repeat that a million times over, and these plants,

and artifacts present windows  into times and places around the world

scientists peer through these windows and test hypotheses about the past.

For example, in the 1950s,  populations of predatory birds,

and eagles started to mysteriously crash,

to the point where a number of species, including the bald eagle,

Fortunately, scientists in  The Field Museum in Chicago

had been collecting the eggs  of these predatory birds for decades.

They discovered that the egg shells  used to be thicker

when an insecticide called DDT  started being sprayed on crops.

but when birds came and ate those heaps of dead bugs,

and was absorbed by apex predator birds in such high concentrations

so that they couldn't support  the nesting bird's weight.

until scientists from  The Field Museum in Chicago,

helped solve the mystery and save the day.

Natural history museums  windows into the past

have solved many other  scientific mysteries.

Museum scientists have used  their collections

discover genes that gave mammoths red fur,

and even pinpoint where  ancient giant sharks gave birth.

There are about 900  natural history museums in the world,

and every year they make  new discoveries and insights

into the Earth's past, present and future.

Museum collections even help us  understand how modern threats,

For instance,  naturalists have been collecting samples

famously immortalized  by Henry David Thoreau.

Thanks to those naturalists, who count Thoreau among their number,

we know that the plants around Walden Pond

are blooming over three weeks earlier  than they did 150 years ago.

Because these changes  have taken place gradually,

one person may not have noticed them over the span of a few decades,

we have an uninterrupted record  showing how our world is changing.

So the next time you're exploring  a natural history museum,

remember that what you're seeing  is just one gem

Behind those walls and under your feet are windows into forgotten worlds.

One day some future scientist may  peer through one and see you.