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Hank: This year is the 100th Anniversary of the National Park Service, and to celebrate we’ve partnered with the The National Trust for Historic Preservation and American Express to give you just a glimpse into how our national parks have benefited the world of science -- and, therefore, all of us here on Earth!

The National Trust and American Express have partnered together to give away two million dollars in grants to preserve historic treasures as part of Partners in Preservation: National Parks. And you can help decide which projects get funded! Just go to VoteYourPark.org to show your support. Until July 5th, you cast five votes per day at VoteYourPark.org.

Now, you might think of national parks as a nice place to see a geyser, or a canyon, or historic landmarks that you don’t typically see around your neighborhood, like cabins and footbridges and lookouts. But there’s more to them than that: there’s tons of scientific research going on, and a lot of awesome discoveries have been made in these parks. Over the past 100 years, US national parks have produced some of the biggest, oldest, deepest, and creepiest discoveries that have been made in this country! Really, there have been too many to talk about in just ten minutes. But if I had to choose 10 of the awesomest discoveries made on park lands? They would definitely include these.

In 1959, an anthropologist exploring Santa Rosa Island, part of Channel Islands National Park in southern California, discovered the bones of an adult male eroding out of a canyon wall. The bones turned out to be more than 13,000 years old — making them likely the oldest human remains ever found in the United States. And this discovery helped fuel a whole new way of thinking about human migration in the New World. The first North Americans came from Asia at the end of the last Ice Age, moving south from Alaska wherever they could find a route that was free of giant glaciers. And for much of the 20th century, anthropologists thought that they must’ve moved down through the middle of the continent. But the discovery made in Channel Islands National Park -- a find that became known as Arlington Springs Man — showed that people had already reached the coast of southern California 13,000 years ago. And what’s more, they were hanging out on islands. This helped spawn what’s now known as the coastal migration theory -- the idea that at least some of the earliest Americans populated the New World by moving south along the Pacific Coast, instead of through the interior.

Do you wanna go back even farther in time? Then, let’s talk dinosaurs. No, let’s actually talk the oldest dinosaur. In 1984, an exquisite set of fossils was discovered in Arizona’s Petrified Forest National Park that turned out not only to be of a new species of dinosaur -- at the time, it was the oldest dinosaur ever found on Earth. The bones belonged to a little, two-legged carnivore -- about the size of a small ostrich -- and they were found in a layer of mudstone that was more than 215 million years old. At the time, this pushed back the known range of dinosaurs some 5 to 10 million years. And the new species, named Chindesaurus has taught us a lot about what life was like back when northern Arizona was swampy marshland. Since the the discovery of Chindesaurus, some older dinosaurs have been found in other parts of the world. But “Gertie,” as the Petrified Forest specimen came to be known, is still probably the oldest dinosaur fossil ever found in the US.

But here’s the thing: Scientists are discovering new species all the time in America’s national parks. Living species! That live among us today! The number of plant and animal species that have been discovered in the parks is almost impossible to pin down, so it might be easier-- and more fun! -- to tell you about the forms of life that have been found only recently! For example! In 2006, teams of biologists set out to explore the network of marble caves that runs under Nevada’s Great Basin National Park. They ended up discovering at least three species of invertebrates that were totally new to science, including a creepy looking pseudoscorpion -- kind of like a scorpion without the stinging tail -- as well as a pale white millipede, and a springtail -- a weird arthropod that escapes danger by flicking its tail to propel itself to safety.

Oh, sorry. Is three new species not enough for you? Well, at Sequoia & Kings Canyon National Park in California, a different research team in 2006 turned up 27 kinds of invertebrates that had never been described before -- including more pseudoscorpions and millipedes, along with previously unknown kinds of pillbugs and spiders.

Now, most of these newly-found species are endemic to the areas where they were discovered, meaning that they’re only found there, but another creature discovered in a national park takes the idea of endemism to the extreme. First recorded in 1930, a species of tiny fish known as the Devil’s Hole pupfish is found only in a single pond of water inside a cavern at Death Valley National Park. In addition to being the rarest fish in the world -- with a population of only 115 as of 2016 -- these tiny fish also have the smallest geographic range of any vertebrate on Earth. This picture shows their entire worldwide habitat.

So, caves and caverns are great places to find species that have never been recorded before, but the caves themselves can be pretty cool too. Kentucky’s Mammoth Cave -- which can be found at its namesake national park -- has long been known as the longest cave on Earth. But in 2013, explorers announced that they had discovered at least 16 new kilometers of caves within the system, and even a previously unknown entrance to the whole thing. But these discoveries weren’t all made at once. It took a team of speleologists -- the scientists who study caves -- several years to find and explore these new underground passages, a little bit at a time. And they’re still being studied, as scientists look for new species, even more new tunnels, and new insights into how the world’s longest cave system came to be.

Now let’s go back to the West Coast, where naturalists exploring Redwood National Park in California made another find for the record books. In 2006, they discovered a coast redwood that stood 115.61 meters tall, making it the world's tallest known tree. They named the tree Hyperion, after one of the Titans from Greek mythology, and ten years later, it still holds the title of the tallest plant on Earth. Now, scientists are looking for even larger trees, which many think are still waiting to be discovered elsewhere in the park.

Some discoveries are made in places that are already national parks. Other discoveries have been so huge that the places where they were made have been turned into national parks. One such place is Thomas Edison National Historical Park in West Orange, New Jersey -- the site of Thomas Edison’s home and laboratory. Edison’s lab witnessed such breakthroughs as the invention of the phonograph -- the first instrument that could record sound AND play it back -- and of course the improvements that Edison and his team made to the incandescent lamp, which involved using a carbon filament carrying an electric current to make a practical light bulb.

Another monument to scientific discovery: The Dayton Aviation Heritage National Historical Park -- also known as the Wright Brothers’ bicycle shop! Sure, everyone knows about Orville and Wilbur’s first flight in North Carolina in 1903 -- but that event was the culmination of years -- you might say, centuries -- of experimentation by generations of engineers. And their Ohio bicycle shop is where the Wrights made their biggest contributions to the science of flight. By the time Orville and Wilbur started working on a vehicle for powered flight in 1899, other engineers had already figured out ways to control some aspects of how an aircraft might move. Like, there were already designs that could control its pitch -- or vertical movement -- as well as its yaw -- or how it moves from side to side. But -- supposedly after watching buzzards flying in circles near their bicycle shop -- Wilbur discovered that there was another factor that no one had thought of: roll -- the rotational movement of a flying object. So, he and Orville designed an aircraft with flexible wings that allowed an on-board pilot to control the vehicle’s roll. And the rest is engineering history.

Finally, no list of the national parks’ contributions to science would be complete without mentioning a little island that’s been the site of the longest-running ecological study in history. On Isle Royale, the largest island in Michigan’s Isle Royale National Park, biologists have been studying the interaction between two charismatic animal species — wolves and moose -- since 1958. Before this research began, it was widely believed that predators and prey always lived in equilibrium, with the proportions of hunters and hunted staying pretty much the same all of the time. But thanks to the contained environment of Isle Royale, scientists were able to study the wildlife in isolation, and discover that that wasn’t actually the case. In the 1970s, the number of wolves spiked dramatically, probably because the population of moose was getting older, and therefore more vulnerable. That meant more food for the wolves, and then more wolves, as females began having more pups, and more pups survived to adulthood. But this only lasted for a few years. Because so much of the moose herd had been hunted, there wasn’t enough food left for the new, bigger wolf population. Suddenly, by the 1980s, the wolf numbers plummeted, and in some cases, the wolves even began attacking each other. Entire books of research have been written about the natural drama that’s played out on Isle Royale. But it won’t last much longer. As of 2016, only two wolves remained on the island.

So, in just a hundred years, the national parks have witnessed all kinds of scientific discoveries. They’ve taught us about life on earth, both below ground and on the surface. We’ve discovered new species -- living among us today, and in the distant past. And they also include places where we learned to fly, and discovered how to illuminate the world. Now, your park needs your help to unlock its part of two million dollars in preservation funding. So head on over to VoteYourPark.org to show your support, where, until July 5th, you cast five votes per day.

And thanks for watching this episode of SciShow, which was brought to you by the US National Park Service and our patrons on Patreon. If you want to help support this show, just go to patreon.com/scishow. And don’t forget to go to youtube.com/scishow and subscribe!