Times Square is an indisputable marvel of the modern world. An Eighth Wonder, if you will. There can be few other experiences, with the exception perhaps of a trip to Tokyo, that compare to the sensation of rising like steam out of New York’s musty subway, being propelled through a revolving door, squinting against the sudden light, and being swept up in a human wave (hundreds of people? thousands?) all with eyes fixed heavenward in a mass state of utter sensory overload.

There are the glittering lights, diverting animated screens, mile-high billboards, and that enormous Cup Noodle in the sky with steam rising appetizingly out of it. You can watch a music video on the side of MTV’s studios as you wait to cross the street and while away hours in the dozens of shrines to capitalism: from M&M candies to a scene from Forrest Gump. If you can detach yourself from the throng, you can buy hot nuts, comedy show tickets, Yankees sweatshirts, and everything else you don’t need.

And I write this as a Gothamite. After a year here, I still gasp and squint and ooh and ah every time I pass through. Even if you’ve been there a thousand times and hate cities and people and entrepreneurship, there is something very wrong with you if you are not dazzled by the spectacle that is Times Square.

New York is a human ecosystem. It is defined by the many humans who have sailed or driven or flown here looking for a new life over the past 400 years, shaping the landscape to their needs. But turn off the bright lights for a second and there’s a bigger story. When Henry Hudson sailed in on September 12, 1609, the island was known to its Lenape natives as “Manahatta,” or “the land of many hills.” I’m not sure at what point the name changed, but presumably it was when they did away with all the hills. It’s very hard to stand in Manhattan today and picture it hilly, but that’s largely because you can’t see much beyond the skyscrapers. There’s no horizon or perspective. But if you choose your location carefully, say, 89th Street between 2nd and 3rd Avenues, or go all the way up to the northwest tip of the island, you’ll see it still does earn its name.

Eric Sanderson of the Wildlife Conservation Society in the Bronx is the project director of The Manahatta Project, which has devoted much of the last decade to fostering awareness of the natural world in this most urban of cityscapes. And it doesn’t get much more urban than New York: in 1950, it was declared the world’s first “mega city” with a population of 10 million people. Even though that number has reduced to 8 million today, the 1.5 million that live on the 23-square-mile Manhattan Island itself — and the millions more that flock to the heart of the city each day to work — makes for a dense population.

When Sanderson first moved to New York from California, he saw the island we all see it: a microcosm of the human footprint on the world, a turbulent web of diverse urban “ecosystems.” From Times Square, the Amazonian-like currents of people and vehicles snake out in every direction, above and under ground. Along manmade avenues creep lines of taxis like yellow beetles. Downtown, Greenwich Village is like an orchard, but instead of trees, you’ll find crooked old buildings, always with character. In contrast, the Financial District features skyscrapers standing straight and tall, like a newly planted forest holding the future paper of America. On the banks of the East River, the delta of the Lower East Side still resembles wasteland in parts. Uptown, the Upper East Side is an older, established wood, with new trees sneaking in that don’t quite blend in with their surrounding. The Upper West Side is a sweeping plain where the avenues always seem just a little broader, and then there’s the colorful, gritty, complexity of Harlem, the last frontier of gentrification. At the center of all of this lies the real-life pasture of Central Park: 843 acres of lawns, trees, water sources, and yes, even rolling hills. It was at Central Park last week where, fittingly, Sanderson offered a free lecture on The Manahatta Project, exhibiting his research into Manhattan’s original ecosystem, and outlining plans for the city’s 400th birthday next year.

The project began when Sanderson came across a British Headquarters Map of Manahatta from 1782. Combining historic and contemporary methods with the antique map, GPS and computer animation, he began to reconstruct the ecology of Manahatta and drew some startling conclusions. It’s often thought that the original ecosystem here was more or less uniformly marshy, rather like the view from the train to and from Newark Airport (which, I must add, is one of the bleakest, most depressing views anywhere in the world). To the contrary, Sanders discovered that Manahatta was originally home to 54 distinct ecosystems. That’s far more than Yosemite National Park. Take that, California!

The diverse human population that characterizes Manhattan today was once an array of wildlife, equally diverse (and dangerous): wolves, elk, mountain lion, deer, beaver, and tens of thousands of birds. Besides birds, you’d be hard-pressed to find any of these creatures here today outside of the Central Park Zoo, although a beaver in the Hudson last year did provoke hope for ecologists. What is today the neighborhood of Inwood was a chestnut grove. A stream ran right down 84th Street, where my apartment building now stands. In fact, Manahatta was full of streams running through forests and wetlands.

Today, these streams are gone, replaced by sewage systems and soggy subways, yet Sanderson’s motive is not to lament the past; rather, it’s to imagine a world without us. According to a recent UN estimate, by 2050, two thirds of the world’s population will reside in cities. Although cities are generally seen as the biggest strain on the environment, Sanderson actually views this as a good thing. More concentrated pockets of human population will, he believes, mean more of the rest of our land can be conserved.

On September 12, 2009, when the Manahatta Project celebrates the city’s quadro-centennial, Sanderson hopes to instill in the city’s inhabitants an appreciation of what lies beneath our feet, beyond the concrete. But instead of attempting to strip away what makes the city great today, he will use animation and art to simulate ecological history in an urban context.

There are many ideas for the celebrations, none set in stone, but the one that captured my imagination the most was the idea to hijack every available screen in Times Square, and replace the images with ones displaying what Manahatta once was. For Manhattan, there’s no going back; it will always be a city. But perhaps for one day next year I’ll be able to rise out of the hot subway, stumble through the revolving doors and gape at stately forests, lush wetlands, and sparkling streams, listen to the call of birds, and breathe in traffic exhaust fumes.

–Julia Clarke