An unfortunate consequence of living in an urban environment is that city folk tend to forget about nature. But for a group of field biologists working with the city parks department, New York City offers some of the most interesting and diverse environmental curiosities. As it turns out, our urban setting has a unique impact on the evolution of plants and wildlife within the city limits. Scouring our city parks, the team, led by Dr. Jason Munshi-South, is uncovering details of some of the interesting biological changes the city brings to its wildlife and animal residents.
Dr. Munshi-South and two graduate students, Paolo Cocco and Stephen Harris, are part of a growing community of scientists and researchers studying Urban Evolution. Using the city as a one big laboratory, they study the biological changes and evolutionary patterns of the city’s plants and animals, ranging anywhere from mice and fish to bugs and bacteria.
Arming themselves with backpacks stuffed with scales, clipboards, rulers, zip lock bags, and tarps, the researchers head out to Highbridge Park, and with the help of Ellen Pehek, a senior ecologist in the NYC Parks and Recreation Department, inspect the contents of field mice traps laid out the day before. On a recent visit, they captured seven mice.
Environmental changes have always had a profound impact on the evolution of species. The advent of cities like NYC, have especially brought along swift environmental changes, steering evolution in a completely new direction. White footed mice for example, originally brought along by European settlers, have now become accustomed to urban stress, and have adopted from living in forests to modern day buildings. Scientists have also identified mutations in more than 1,000 genes in NYC mice, as compared to mice from other parks upstate.
Dr. Munshi-South and his research colleagues have also discovered that mice who settle in different parks around the city each have genetically distinct DNA. “The amount of differences you see among populations of mice in the same borough is similar to what you’d see across the whole southeastern United States,” he said to the New York Times.
Fish swimming along the Hudson River have experienced a very interesting change due in large part to environmental pollution. Once susceptible to deformities due to PCBs in the water, fish larvae were plagued with deformities. The fish, however,have now evolved to the point where they are resistant to PCBs and other poisons in the river.
Evolution isn’t only occurring in parks and green spaces. Bacteria in hospitals have also mutated in response to the pressures of the city. In 1997, Dr. John Quale of the SUNY Downstate Medical Center discovered that Klebsiella pneumoniae, a bacteria often found in hospitals and known to cause pneumonia and other life threatening infections, has become resistant to antibiotics. Once it established itself in NY, it spread to 33 other states, and countries like France, Greece and Israel, where it is still a menace. In fact, half the patients who get infected by the bacteria end up dying, and while there have been recent advancements in treatment, only toxic drugs that can cause nerve and liver damage are the only effective way to cure some infections.
Biologists have found a mix of native and non-native life forms all across NYC, including trees in Central Park and birds in Jamaica Bay. Some, like the Prospect Park geese, have even caused quiet a bit of controversy. The biodiversity is the a result of “extinctions, invasions and adaptations”. Unfortunately, due to severe environmental changes and pollution, not all of it has been good. Manhattan was once home to 21 native species of orchids, which are now all extinct.
Scientists have also found that 401 native plant species have vanished from NYC since 1624. Now, only 1,159 remain. The main cause of the native flora extinction is due to the areas change from woodland to open urban spaces. No longer able to survive without closed forests, many plant species are slowly disappearing.
Many non-native species have also quickly died out. Some have found a comfortable home as part of the city’s wildlife, while have caused damaged to many native species. New York, for example, was “the port of entry for Dutch elm disease, chestnut blight, Asian longhorned beetles and other threats to trees across the country.”
The main challenge for many biologists now is to try to balance the native species of NYC with invasive wildlife. Add pollution into the mix, and the situation becomes more complicated. The great thing about this new breed of scientists is that through the study of Urban Evolution, we can catch a glimpse at one aspect of NYC that isn’t well known. Through Urban Evolution, we easily see that cities have a natural environment far more diverse then originally thought.