This is Scientific American 60 Second Science.

I'm Christopher in D'Alga.

Got a minute?

A 2014 analysis found that New York City's Queens was the most ethnically diverse county in the continental U.S.

But when it comes to the diversity of DNA found in each borough's subway stops,

the Bronx takes the prize.

I live in Brooklyn, so I was kind of hoping Brooklyn might be top of the list but we're second

place.

Manhattan in the middle and then Queens and then Staten Island.

Christopher Mason, a geneticist.

A very curious geneticist I'd say.

At the Wild Cornell Medical College in Manhattan.

Mason's curiosity led him and his colleagues on a five borough tour of New York's

468 subway stations in the Staten Island Railway.

They swabbed turnstiles, kiosks, benches,

trash cans, railings, and subway cars,

then sequenced every bit of DNA they found.

The result...

The subway kind of looks like skin.

Meaning they found a whole lot of bacteria, like Pseudomonas, that also live on our skin.

The DNA at each subway stop mirrored the genetic diversity of the local residents and what they like to eat.

We could see other evidence of things like molecular echoes of pizza, cucumbers, as well as chickpeas

...