CITIES TEEM WITH LIFE BOTH VISIBLE AND INVISIBLE. In an effort to bring the invisible to light, volunteers from Genspace, a community lab in New York City, used microbial samples collected from around the city to create this map of Manhattan built from petri dishes. The project was inspired by researchers at Weill Cornell Medical College, who in 2013 and 2014 were working on their own genomic portrait of New York City. After sequencing DNA collected from public surfaces, the researchers at Weill Cornell found that nearly half of the samples did not match any known organism and that drug-resistant bacteria were in evidence. But the human DNA the study found on subways was less surprising: The predicted racial makeup it yielded neatly matched the U.S. Census demographic data for the city.