DNA is everywhere, even in the air. That’s no surprise to anyone who suffers allergies from pollen or cat dander. But two research groups have now independently shown the atmosphere can contain detectable amounts of DNA from many kinds of animals. Their preprints, posted on bioRxiv last week, suggest sampling air may enable a faster, cheaper way to survey creatures in ecosystems.
The work has impressed other scientists. “The ability to detect so many species in air samples using DNA is a huge leap,” says Matthew Barnes, an ecologist at Texas Tech University. “It represents an exciting potential addition to the toolbox.”
“The surprising part is that you’re able to get birds and mammals—wow,” says Julie Lockwood, a molecular ecologist at Rutgers University, New Brunswick. The new studies suggest “there’s more than just spores; there’s cells and hair and all kinds of interesting things that float through the air.”
For more than a decade, researchers have analyzed those disparate sources of DNA in water to identify elusive organisms. Researchers’ sampling of environmental DNA (eDNA) in lakes, streams, and coastal waters has let them identify invasive species like lionfish as well as rare organisms such as the great crested newt. More recently, some scientists have tracked insects by eDNA on leaves, and also found soil eDNA apparently left by mammals loping along a trail.