(Undark) – The swabbers were sampling what’s called environmental DNA, or eDNA, representing the assortment of cells that all humans, animals, and microorganisms naturally shed as they go about their everyday lives, leaving genetic fingerprints. The scientists gradually quantified and mapped the unseen biological diversity — the microbiome — of the entire city. In 2015, they reported that they’d found more than 1,600 different types of microbes, nearly half of which were previously known to science. Most were harmless, associated with human skin and gastrointestinal tracts. About 12 percent were known pathogens, including fragments of genomes similar to Bubonic plague and anthrax, though there was no evidence that these small bits could make anyone sick. They hadn’t found any new deadly viruses lurking in New York’s underground — yet. (Read More)