Tracie Seimon of WCS’s Zoological Health Program collecting eDNA sample. Credit: Anton Seimon/National Geographic
Key Points:
- Environmental DNA (eDNA) has revealed the extensive biodiversity located on the highest mountain on Earth.
- The DNA of the species revealed many insights, including the influence of humans, a changing environment and the effect of wind.
- The research team hopes to expand the open-dataset in the future to better track the evolving ecosystem.
A team of scientists led by the Wildlife Conservation Society (WCS) and Appalachian State University used environmental DNA (eDNA) to document the extensive breadth of biodiversity present on Mt. Everest, the Earth’s highest mountain.
For the study, published in iScience, the team collected eDNA from water samples in 10 ponds and streams between 4,500 and 5,500 meters over a 4-week period. The sites included areas of the alpine zone that exist above the tree line, as well as the aeolian zone, which reaches beyond the range of flowering plants and shrubs at the uppermost reaches of the biosphere.
From just 20 liters of water, the research team identified organisms belonging to 187 taxonomic orders, which corresponds to 16.3 percent of the total known orders across the tree of life—a family tree of Earth’s biodiversity.
Finding the DNA of these organisms in such a harsh environment revealed interesting insights to the team. For example, the scientists were surprised to find domestic dog and chicken, indicating the influence of human activities even at 29,032 feet high. They also identified pine trees, which only are found far downhill from where samples were taken, demonstrating how wind-blown pollen can make its way high up into these watersheds. Another organism they identified from several sites were mayflies, which are known indicator species for environmental change.
The team was less surprised to identify both rotifers and tardigrades, two tiny animals best known for their ability to survive in the most extreme environments, making them among the most resilient animals known on Earth.
“We went in search for life on the roof of the world. This is what we found,” said study author Marisa Lim of the Wildlife Conservation Society. “However, the story does not end here. There is more to be discovered and we hope our findings help to inform future exploration.”
The eDNA inventory, part of the 2019 National Geographic and Rolex Perpetual Planet Everest Expedition, will aid future high-Himalayan biomonitoring and retrospective molecular studies to assess changes over time as climate-driven warming, glacial melt, and human-caused influences reshape the ecosystem.
The scientists have shared their findings as an open-source dataset in the hope others will contribute toward its expansion.
Information provided by Wildlife Conservation Society.