Viruses Are Likely To Be Ubiquitous Throughout Cosmos – Forbes

artistic impression of a great discovery

As this wretched COVID-19 disease has so acutely demonstrated, we live in an ecological duopoly of predator versus prey.Nothing about this set-up is going to change.At least a part of this microbial world is going to continue to wreak havoc on humans anytime it can.

Thus, in our current quest to move off-world, first to the Moon and Mars, then even further afield what are the chances that any given exo-earth will also harbor microbes that will be lethal to other living organisms?In other words, will this predator versus prey dynamic play out on a grand cosmic scale?

Most if not all ecosystems on Earth depend on some life forms feeding on other life forms for energy or other nutrients.I don't see any reason that this would not be similar on exoplanets that harbor life, Ken Stedman, a virologist at Portland State University in Oregon, told me.

Would viruses be ubiquitous wherever life evolves?

Wherevercellular life evolves first, says Stedman.Thats because virusesneed to infect a living cell in order to reproduce, he says.

The inert virion, the viral form visible under the electron microscope, is analogous to a seed or a spore that can only replicate in an appropriate environment, Stedman and co-authors write in a 2018 paper appearing in Astrobiology Journal.It then reprograms the cellular machinery to produce more virions, and the release of virions from the host cell to infect other cells, the authors write.

People walk dogs in New York's Times Square, Wednesday night, April 29, 2020, during the coronavirus ... [+] pandemic. (AP Photo/Mark Lennihan)

As for SARS-CoV-2, the virus that causes COrona VIrusDisease-2019?

SARS-CoV-2 infects human cells (and possibly bat cells) and causes these cells to make more SARS-CoV-2, says Stedman.A lot of COVID-19 disease is due to our immune system's reaction to the viral infection, not the virus infection itself, he says.

But viruses arent all bad.

Over billions of years of evolution, multicellular organisms have been prodded and provoked to adapt and evolve to counter the deleterious infections of all manner of viruses.Even Earths ecosystem has been impacted by viruses.

Up until some 2 billion years ago, Earths atmosphere was pretty much devoid of molecular oxygen (O2), notes a 2013 report from the American Society of Microbiology (ASM).Thats when oxygen levels on Earth rose in what is now known as the Great Oxidation Event, which coincided with oxygenic photosynthesis.

Although cyanobacteria drove photosynthesis in the worlds oceans, the ASM report notes, a good portion of the cyanobacterias photosynthetic activity, may be attributed to viral cyanophages (viruses that infect bacterial cells). Thats because many cyanophages infect cyanobacteria and encode photosynthetic proteins within the bacteria. Its thought that the expression of these photosynthesis genes during infection not only promotes photosynthesis in the host, but also cyanophage replication, the ASM report concludes.

Without viruses on Earth, life [here] would probably be a layer of slime, said Stedman.

Corona Virus with Triangle Shapes Lines And Dots Forming A Plexus

As for ideas on how viruses actually originated, some researchers think they may either be genes that escaped from cells; or descendants of some of Earths earliest life forms.

Viruses are the only life-forms that use RNA as their primary genetic material, says Stedman.

Its now thought that the nucleic acid RNA evolved on Earth before DNA. Thus, as Stedman and colleagues wrote in their 2018 Astrobiology Journal paper, todays viruses may be descendants of viruses or similar replicative entities that existed in this hypothetical RNA world.

And if in the far future, humans colonized an exo-earth, or even Mars and found viruses there, would the viruses be able to infect our cells the same way they do on Earth?

Stedman says that would be highly unlikely unless there was life on an exo-earth that was extremely human-like.

What prevents viruses from infecting a host cell?

Thecell has to have the appropriate receptor on the cell surface (that the virus has evolved to interact with), says Stedman.And the cell has to have the machinery that the virus needs to make more virus, he says.

What about detecting viruses on an extrasolar earth?

Thus far, astronomers have no viable means of remotely detecting exo-viruses, says Stedman.

We are trying to develop methods to change that, but are not there yet, he says.

As for finding viruses on Mars?

I would love to put an electron microscope on a rover, but that has not yet been done, said Stedman.

Alien microbes in space above Mars, conceptual illustration. Mars once had a wet climate, which ... [+] prompts many astronomers to believe that life may have arisen there in the past, and perhaps exists there still. This illustration conceptualises the idea, showing microorganisms floating above Mars. In 1996, NASA announced that they had found evidence for fossilised microorganisms in a meteorite hailing from Mars. However, whether these structures are indeed fossilised life forms or merely Earth-based contaminants remains unsettled.

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Viruses Are Likely To Be Ubiquitous Throughout Cosmos - Forbes