Viruses From Distant Lands Fall from the Sky

Every day, billions of viruses are carried by high winds from continent to continent.

There’s no escape. Our planet is swarming with viruses. UBC Science describes new measurements from mountaintops in Spain, saying, “An astonishing number of viruses are circulating around the Earth’s atmosphere – and falling from it – according to new research from scientists in Canada, Spain and the U.S.” The number of viruses they found is 9 to 461 times as high as for bacteria carried aloft.

“Every day, more than 800 million viruses are deposited per square metre above the planetary boundary layer—that’s 25 viruses for each person in Canada,” said University of British Columbia virologist Curtis Suttle, one of the senior authors of a paper in the International Society for Microbial Ecology Journal that outlines the findings.

The viruses are swept up by sea spray and by winds over the land. Carried upward above the clouds, they can be transported across continents before rains and Sahara dust intrusions deposit them back onto the land. This helps explain why genetically identical viruses have been found in different environments around the globe.

Evolution News reported that tens of thousands of bacteria live in dust grains carried by clouds. The article asked whether the global transport of biological systems might be necessary for a  planet’s habitability. Another article on Evolution News considered the rich biological communities that live in soil biocrusts. These ecosystems could possibly neutralize some of the static electricity that plagues the planet Mars, the moon, and Saturn’s large moon Titan.

For all we know, the dust carrying genetic information around the earth could be for our good. Nature reported that “Dirt yields potent antibiotics.” Some microbes found in soil produce antibiotics able to conquer some of today’s most feared antibiotic-resistant bacteria:

One gram of soil contains at least 1,000 bacterial species. To explore the medical potential of that diversity, Sean Brady at the Rockefeller University in New York City and his colleagues analysed roughly 2,000 soil samples collected across the United States. The researchers extracted DNA from the samples and screened it for genetic sequences involved in the production of antibiotics by various bacteria.

The search turned up a new family of antibiotics that the team named ‘malacidins’. The compounds kill many formidable pathogens, including a microbe resistant to vancomycin, which is considered to be the antibiotic of last resort. When applied to the skin of rats, the new antibiotics sterilized wounds infected with methicillin-resistant Staphylococcus aureus (MRSA), a bacterium that can ravage large expanses of tissue.

There could be acres of diamonds all around us, microbes with cures for disease, inoculating us against the worst infections if we only knew all that these tiny travelers on dust particles are there for.

Microbes and viruses live everywhere, from the ocean floor to the high atmosphere. These invisible realities may do far more for the earth than we realize: they may contribute to its habitability. The ubiquity of organisms also indicates that the earth is the Information Planet. Even the clouds “are perfused with huge amounts of complex specified information: the genetic codes of tens of thousands of organisms.”