Rats! Everyone’s favorite cute little fuzzy…hm?…wait, really?….kill with fire, huh?

I’m being told a lot of people don’t like rats. But too bad. I’m talking about them today. Rats in New York City (a city made famous by Jay-Z and Alicia Keys) have been a fundamental part of the city for literally centuries. They are all descended from Western European rats, and were likely brought by original colonial settlers of New Amsterdam (why’d they change it?). Despite the constant influx of immigrants to the Big Apple from all over the world, the dominance of Western European rats has persisted.

These rats are not all the same, however. A graduate student at Fordham University, out of his own free will, has decided to study the genetic makeup of Manhattan Rats (note to self, would be a good band name). What he discovered was that there is a distinct genetic difference between Uptown Rats and Downtown Rats, which could potentially be the first step on the way towards two distinct species.

Ok, if you’re good on the process of evolution via natural selection, go ahead and take five. Hands up if you’re not, though. Oh, ok, wow, that’s more than I was expecting. Ok, ok, bear with me for a minute.

Remarkably for his time and resources, Charles Darwin got it pretty much fucking right in his On the Origin of Species (which is a surprisingly good read). Serving as a geologist and naturalist for the HMS Beagle, Darwin observed that groups of the same species that were in different environments would have physical traits more suited to their environment. The most famous example of this was the Galapagos finches, which had beaks that were perfectly designed to whatever food source was most abundant on that island; large beaks for crushing seeds and nuts, more delicate grasping beaks for insects and fruit. He theorized that, given enough time, the differences would become large enough that the sub-populations would become different species. He also collected many fossils on the voyage, including species that did not exist anymore. This provided further evidence that the planet’s diversity was not a static distinction between organisms, but rather a constantly changing and blurry continuum, adapting to the dynamic environment.

His theory, combined with the advent of the new field of genetics, provided the mechanism for the creation of the massive biodiversity of this planet, from single-celled bacteria, to the redwood, to the peregrine falcon, to whatever Nick Nolte is. It provides the explanation for what is occurring in New York City right now – an artificial barrier produced by the commercial heavy midtown, that lacks the household garbage and backyards that rats love oh so much. They could even narrow down genetic distinctions of rats that matched up with traditional human neighborhoods.

So sorry Billy Joel,  Uptown Rats don’t appear to be looking for Downtown Rats, but further studies will be needed to determine if only good rats die young.


The Atlantic

Wiley Online