David Duffy, a wildlife geneticist at the University of Florida, just wanted a better way to track disease in sea turtles. Then he started finding human DNA everywhere he looked.
Over the last decade, wildlife researchers have refined techniques for recovering environmental DNA, or eDNA — trace amounts of genetic material that all living things leave behind. A powerful and inexpensive tool for ecologists, eDNA is all over — floating in the air, or lingering in water, snow, honey and even your cup of tea. Researchers have used the method to detect invasive species before they take over, to track vulnerable or secretive wildlife populations and even to rediscover species thought to be extinct. The eDNA technology is also used in wastewater surveillance systems to monitor Covid and other pathogens.
But all along, scientists using eDNA were quietly recovering gobs and gobs of human DNA. To them, it’s pollution, a sort of human genomic bycatch muddying their data. But what if someone set out to collect human eDNA on purpose?
New DNA collecting techniques are “like catnip” for law enforcement officials, says Erin Murphy, a law professor at the New York University School of Law who specializes in the use of new technologies in the criminal legal system. The police have been quick to embrace unproven tools, like using DNA to create probability-based sketches of a suspect.
That could pose dilemmas for the preservation of privacy and civil liberties, especially as technological advancement allows more information to be gathered from ever smaller eDNA samples. Dr. Duffy and his colleagues used a readily available and affordable technology to see how much information they could glean from human DNA gathered from the environment in a variety of circumstances, such as from outdoor waterways and the air inside a building.
The results of their research, published Monday in the journal Nature Ecology & Evolution, demonstrate that scientists can recover medical and ancestry information from minute fragments of human DNA lingering in the environment.
Read More: Your DNA Can Now Be Pulled Out Of Thin Air