Most people think of viruses as disease-causing germs propelled through the air by a sneeze or lying dormant on a doorknob waiting for the touch of an unsuspecting victim. But viruses are far more important — and beneficial — than you may realize.
Viruses help keep ecosystems in balance by keeping bacteria in check. They may have played a crucial role in the evolution of mammals, and even in the development of human consciousness. According to one group of researchers, viruses "modulate the function and evolution of all living things".
And every day, trillions and trillions of viruses fall out of the sky:
Scientists have surmised there is a stream of viruses circling the planet, above the planet’s weather systems but below the level of airline travel. Very little is known about this realm, and that’s why the number of deposited viruses stunned the team in Spain. Each day, they calculated, some 800 million viruses cascade onto every square meter of the planet.
What's even more amazing is that we're not sure exactly where they all come from. Do they originate on the surface of the Earth and get stirred up into the air? Do they originate in the atmosphere and fall downward? Or is it possible, as some researchers have theorized, that viruses came from outer space?
I don't know if we'll ever have all the answers, but I find it fascinating. And a little scary.
📷: Bacteriophages attached to a bacterial cell wall. By Dr. Graham Beards, CC BY-SA 3.0