Climbers on Everest are leaving microbes that might give us clues to finding life on other planets, scientists believe.
Researchers looked at frozen microbes nearly five miles up the mountain and were surprised that many, usually found in warm wet places like our throats, were surviving in the harsh environment.
At such high elevation, microbes are often killed by ultraviolet light, cold temperatures and low water availability.
But the team from the University of Colorado at Boulder found microbial DNA for some organisms heavily associated with humans.
These included Staphylococcus, one of the most common skin and nose bacteria, and Streptococcus, found in the mouth and which can cause sore throats.
They say that the find has implications for the potential for life far beyond Earth, if one day humans step foot on Mars or beyond.
Dr. Steve Schmidt, senior author on the paper and professor of ecology and evolutionary biology said: “There is a human signature frozen in the microbiome of Everest, even at that elevation.
“If somebody even blew their nose or coughed, that’s the kind of thing that might show up.
“It could lead to a better understanding of environmental limits to life on Earth, as well as where life may exist on other planets.
“We might find life on other planets and cold moons. We’ll have to be careful to make sure we’re not contaminating them with our own.” said Schmidt.
The researchers got soil samples from the South Col 26,240 feet up (7,900m) where every year hundreds camp before setting off for the final push to the summit.
Dr. Baker Perry, co-author, professor of geography at Appalachian State University and a National Geographic Explorer, hiked as far away from the South Col camp as possible to scoop up some soil samples to send back.
Until now, scientists have been unable to conclusively identify human-associated microbes in samples collected above 26,000 feet.
So the team used next-generation gene sequencing technology for the first time to analyze the soil enabling researchers to gain new insight into its contents.
“They were able to identify the DNA and carry out extensive Bioinformatics analyzes of the DNA sequences to determine the diversity of organisms rather than their abundance,” said the research.
They believe the microbes can lie dormant in the soil for decades or even centuries.
Although they weren’t surprised to find human microbes, what surprised them was that they were resilient enough to survive in a dormant state in such harsh conditions.
The most abundant were from a hardy type of fungus known to survive high up that might even have grown if they had the odd bit of sunlight and water.
Dr. Schmidt added: ‘Our data suggest that the South Col and other extremely high-elevation environments may be deep-freeze collection points for deposited organisms, including human-borne contaminants that may never leave once they arrive.”
Produced in association with SWNS Talker
Edited by Judy J. Rotich and Newsdesk Manager