University of Arizona astrobiologist Paul Davies, author of many books, including the recent What’s Eating the Universe? (2021), told The Guardian, recently that if cellular life exists on other planets, something like viruses probably also exist — to transfer genetic information from one life form to another.

Viruses, said Davies, can be thought of as mobile, genetic elements. Indeed, a number of studies have suggested genetic material from viruses has been incorporated into the genomes of humans and other animals by a process known as horizontal gene transfer.

Nicola Davis, “Viruses may exist ‘elsewhere in the universe’, warns scientist” at The Guardian (September 6, 2021)

Horizontal gene transfer, by which life forms “swap” genes, are common in bacteria and have been found in many other types of life. It’s called horizontal because the donor is not in a parent/offspring (vertical) relationship with the recipient. The recipient simply incorporates the donor’s gene(s) and later passes them on in the usual fashion.

According to Davies, while the importance of microbes to life is well known, the role of viruses is less widely appreciated. But he said if there is cellular life on other worlds, viruses or something similar, would probably exist to transfer genetic information between them.

Nicola Davis, “Viruses may exist ‘elsewhere in the universe’, warns scientist” at The Guardian (September 6, 2021)

One research team wrote, for example, “ Our findings imply that horizontal transfer of double-stranded RNA viral genes is widespread among eukaryotes and may give rise to functionally important new genes, thus entailing that RNA viruses may play significant roles in the evolution of eukaryotes.” – PubMed (2010)

Horizontal gene transfer is a key way that bacteria rapidly develop antibiotic resistance.

Davies hastened to point out that extraterrestrial viruses are unlikely to be harmful if we were to come into contact with them. It is the viruses close to us that we must worry about.

Essentially, if life evolves on other planets, we might expect to find that viruses are one of the ways that important genetic information gets transferred between them.

You may also wish to read: COVID-19: When 900 bytes shut down the world. A great physicist warned us, information precedes matter and energy: Bit before it. The coronavirus contains about as much information as a sticker at WhatsApp. But what a difference it has made.