Hidden DNA is revealing secrets of animals’ lives

Hidden DNA is revealing secrets of animals’ lives Select your native language from the sidebar for translations, tap for pronunciation

eDNA, shed by plants and animals are providing astonishing biological insights Select your native language from the sidebar for translations, tap for pronunciation

It had been more than 140 years since A two-legged, foot-long salamander Select your native language from the sidebar for translations, tap for pronunciation protected by the state of Texas—had been found near Eagle Pass Select your native language from the sidebar for translations, tap for pronunciation a town on the United States-Mexico border Select your native language from the sidebar for translations, tap for pronunciation But in 2019, biologist Krista Ruppert realized Select your native language from the sidebar for translations, tap for pronunciation that she just needed a pitcher of muddy water to filter Select your native language from the sidebar for translations, tap for pronunciation to prove they were still there Select your native language from the sidebar for translations, tap for pronunciation At Eagle Pass, Ruppert found enough environmental DNA—trace genetic material Select your native language from the sidebar for translations, tap for pronunciation left behind as organisms crawl, swim, or flap their way through life Select your native language from the sidebar for translations, tap for pronunciation to establish that the elusive amphibians still live in the area Select your native language from the sidebar for translations, tap for pronunciation In the last decade or so, environmental DNA, or eDNA Select your native language from the sidebar for translations, tap for pronunciation has revolutionized marine and aquatic research Select your native language from the sidebar for translations, tap for pronunciation by allowing scientists to sample “an entire ecosystem” with a liter of water Select your native language from the sidebar for translations, tap for pronunciation eDNA has become biologists’ skeleton key Select your native language from the sidebar for translations, tap for pronunciation as it’s a relatively cheap, noninvasive, and simple technique Select your native language from the sidebar for translations, tap for pronunciation that can be modified to study any form of life Select your native language from the sidebar for translations, tap for pronunciation and it often requires less time and labor than previous methods Select your native language from the sidebar for translations, tap for pronunciation

Stop and swab the roses

In 2017, researchers from Denmark Select your native language from the sidebar for translations, tap for pronunciation plucked a bouquet of wildflowers from two Danish fields Select your native language from the sidebar for translations, tap for pronunciation and popped them into a chemical bath to extract any DNA on their surface Select your native language from the sidebar for translations, tap for pronunciation A single wild celery flower had DNA from 25 species of arthropods Select your native language from the sidebar for translations, tap for pronunciation Overall they detected eDNA from at least 135 species with tremendous diversity Select your native language from the sidebar for translations, tap for pronunciation including species that have a very short time span of interactions Select your native language from the sidebar for translations, tap for pronunciation eDNA samples taken from flowers could provide insight into Select your native language from the sidebar for translations, tap for pronunciation a region or plant species’ most active pollinators Select your native language from the sidebar for translations, tap for pronunciation

Pathogens in the sand

A team of scientists in Florida has recovered genetic material Select your native language from the sidebar for translations, tap for pronunciation from the flipper prints left by individual loggerhead turtle hatchlings Select your native language from the sidebar for translations, tap for pronunciation weighing about two quarters, making their way to the sea Select your native language from the sidebar for translations, tap for pronunciation Further analysis demonstrated that eDNA can also help the monitoring of disease Select your native language from the sidebar for translations, tap for pronunciation The tiny tracks also contained eDNA from ChHV5 Select your native language from the sidebar for translations, tap for pronunciation a virus that causes the debilitating cancerous growths in young turtle Select your native language from the sidebar for translations, tap for pronunciation The discovery challenges the presiding theory Select your native language from the sidebar for translations, tap for pronunciation that the disease is passed horizontally Select your native language from the sidebar for translations, tap for pronunciation either through the water or through contact between turtles Select your native language from the sidebar for translations, tap for pronunciation This possibly means that vertical transmission Select your native language from the sidebar for translations, tap for pronunciation from mother to hatchling is also at play Select your native language from the sidebar for translations, tap for pronunciation which would have a really big knock-on effect Select your native language from the sidebar for translations, tap for pronunciation in terms of how this disease could be mitigated Select your native language from the sidebar for translations, tap for pronunciation

Clear blue skies

Christina Lynggaard used a variety of vacuums Select your native language from the sidebar for translations, tap for pronunciation to suck up air at the Copenhagen Zoo Select your native language from the sidebar for translations, tap for pronunciation By filtering air at several sites across the zoo Select your native language from the sidebar for translations, tap for pronunciation Lynggaard ultimately detected 49 species of animals Select your native language from the sidebar for translations, tap for pronunciation even fish that were fed to predator species Select your native language from the sidebar for translations, tap for pronunciation But what was missed was almost as fascinating as what they found Select your native language from the sidebar for translations, tap for pronunciation Some species were never detected Select your native language from the sidebar for translations, tap for pronunciation she thought, if she was smelling any scent that they’re putting off Select your native language from the sidebar for translations, tap for pronunciation then there must be DNA being carried with those droplets Select your native language from the sidebar for translations, tap for pronunciation But eDNA from the zoo’s most stinky resident Select your native language from the sidebar for translations, tap for pronunciation a maned wolf, evaded their filters Select your native language from the sidebar for translations, tap for pronunciation

The open ocean

Population dynamics for the whale shark Select your native language from the sidebar for translations, tap for pronunciation an enigmatic giant that doesn’t need to surface for air Select your native language from the sidebar for translations, tap for pronunciation remain something of a mystery to scientists Select your native language from the sidebar for translations, tap for pronunciation To learn about them scientists typically use spears to take biopsies from their bodies Select your native language from the sidebar for translations, tap for pronunciation But by collecting eDNA samples a few meters behind whale sharks Select your native language from the sidebar for translations, tap for pronunciation Dugal and her team obtained clear enough reads Select your native language from the sidebar for translations, tap for pronunciation to determine individual sharks’ genetic markers that provide information Select your native language from the sidebar for translations, tap for pronunciation on where its ancestors lived and its relatedness to other populations Select your native language from the sidebar for translations, tap for pronunciation They were a perfect match for traditional biopsies taken from the same individuals Select your native language from the sidebar for translations, tap for pronunciation

Invertebrate informants

A flourishing subfield of eDNA is iDNA, or invertebrate-acquired DNA Select your native language from the sidebar for translations, tap for pronunciation Early studies on sea sponges have found Select your native language from the sidebar for translations, tap for pronunciation they create accidental eDNA repositories as they filter-feed Select your native language from the sidebar for translations, tap for pronunciation while leeches contain a genetic record of their past blood meals Select your native language from the sidebar for translations, tap for pronunciation that can last as long as four months Select your native language from the sidebar for translations, tap for pronunciation Researchers have also recovered species-level DNA from Select your native language from the sidebar for translations, tap for pronunciation the guts of dung beetles that dined on other animals’ faeces Select your native language from the sidebar for translations, tap for pronunciation

Tea leaves that tell the past

A German team reported finding eDNA from 1,279 distinct species Select your native language from the sidebar for translations, tap for pronunciation of insects, spiders, and other arthropods in teas and spices purchased in grocery stores Select your native language from the sidebar for translations, tap for pronunciation This finding unlocks a potential treasure trove of new data Select your native language from the sidebar for translations, tap for pronunciation as the historical botanical specimens collected around the world for centuries Select your native language from the sidebar for translations, tap for pronunciation could contain information on the species that surrounded them in life Select your native language from the sidebar for translations, tap for pronunciation

No ‘silver bullet’

But even eDNA’s biggest proponents say it’s just a supplement Select your native language from the sidebar for translations, tap for pronunciation and not a replacement, for traditional field sampling techniques Select your native language from the sidebar for translations, tap for pronunciation So far, eDNA can’t reveal an organism’s age, sex, or body condition Select your native language from the sidebar for translations, tap for pronunciation Still, it’s hard to overstate the sense of wonder scientists feel Select your native language from the sidebar for translations, tap for pronunciation at the power of the technique Select your native language from the sidebar for translations, tap for pronunciation