When you think of natural history museums,
you probably picture exhibits
filled with ancient lifeless things,
like dinosaurs
meteroites,
and gemstones.
But behind that educational exterior,
which only includes
about 1% of a museum's collections,
there are hidden laboratories
where scientific breakthroughs are made.
Beyond the unmarked doors,
and on the floors
the elevators won't take you to,
you'd find windows into amazing worlds.
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,
cosmic origins,
and the history of our planet.
One museum alone
may have millions of specimens.
The American Museum of Natural History
in New York City
has over 32,000,000 in its collection.
Let's take a look at just one of them.
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,
animals,
minerals,
fossils,
and artifacts present windows into times
and places around the world,
and across billions of years of history.
When a research problem emerges,
scientists peer through these windows
and test hypotheses about the past.
For example, in the 1950s, populations
of predatory birds,
like peregrine falcons,
owls,
and eagles started to mysteriously crash,
to the point where a number of species,
including the bald eagle,
were declared endangered.
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,
and had started to thin around the time
when an insecticide called DDT
started being sprayed on crops.
DDT worked very well to kill insects,
but when birds came
and ate those heaps of dead bugs,
the DDT accumulated in their bodies.
It worked its way up the food chain
and was absorbed by apex predator birds