Identifying an area’s inhabitants by vaccuming their DNA out of the air: That sounds like something from a science fiction story. But a study published in the journal Current Biology
explains that scientists found that air quality monitoring stations also pick up lots of DNA. That can reveal which plants and animals have been in the area.
As animals and plants go through their life cycles, they leave little bits of themselves in the environment. Those bits include scales, fur, feathers, skin cells, dander, pollen. (Humans leave some of these behind too.) Many of those bits carry a genetic signature. That shed DNA is known as environmental DNA (eDNA).
Scientists have long found eDNA in water. Some have used it to track species that inhabit lakes and rivers. But it’s been harder to get a genetic picture of what’s roaming on land, says Kristine Bohmann, who studies eDNA.
In 2021, Bohmann and biologist Elizabeth Clare worked on separate but similar projects to see whether they could pull animal DNA from thin air. After setting up vacuum pumps in zoos, the teams were able to sequence DNA from dozens of species.
Researchers wanted to try that on a bigger scale.
For the latest study, Clare and her team tested air filters from two monitoring stations, one in England and one in Scotland. Those are part of national networks to test for pollution.
After extracting DNA from pieces of the filter disks, the scientists identified more than 180 different kinds of plants and animals, including grasses, fungi, deer, hedgehogs, and songbirds.
Biodiversity—the variety of living creatures in an area—is declining in many places. But it’s hard to test for on a large scale, Clare says. Now the team hopes that this method could observe ecosystems all over the world. Even if researchers can’t spot a creature, maybe they could identify it in an area by finding its DNA.
And they could use systems that are already in place. Many countries have networks set up to monitor air quality. Some of them store old filters for years or even decades. Those archives could help show how ecosystems have changed over time.
What’s next could be even more science-fiction-esque. Researchers find human eDNA in the air too. That could help archaeologists learn about the past or provide forensic information to law enforcement. But working with human eDNA raises ethical and privacy concerns. For now, at least, maybe scientists using this method should stick to tracking animals.
Why? God gave humans the job of stewarding His creation. Scientific research and God-given creativity can reveal tools to help.