We are living in a tough time.
The spread of COVID-19 is a generational event. We will remember 2020 for years and years to come.
We can’t begin to imagine the changes this pandemic will prompt. The changes to our current day-to-day lives—in countries across the world—are enormously disruptive. It’s very hard to understand what life will look like when the threat from this pandemic subsides. (And it will.)
As doctors and health care workers treat the large numbers of those who are suffering, it might be difficult to shift to a big-picture view of what’s going on. By moving to a wider lens, we don’t mean to minimize the current strife.
But it’s also worth noting that any epidemic—any pandemic—is an evolutionary event.
A 2016 study conducted by scientists at Stanford University—and presented the same year at the Allied Genetics Conference—demonstrated the full extent of the impact of viruses on the evolution of humans and other mammals.
In fact, the study suggested that viruses deserve (if that’s the right word) about 30 percent of all protein adaptations since the divergence of humans from chimpanzees.
As an article about the study on Psy.Org explains, proteins perform a vast array of functions that keep human cells ticking. Most prior research had focused on those individual proteins that were directly involved in the immune response—the proteins under attack by the pathogen. This study took a global look at the impact on all proteins.
“The big advancement here is that it's not only very specialized immune proteins that adapt against viruses,” said David Enard, Ph.D., a postdoctoral fellow at Stanford University and the study's first author. “Pretty much any type of protein that comes into contact with viruses can participate in the adaptation against viruses. It turns out that there is at least as much adaptation outside of the immune response as within it.”
Enard and his team identified 1,300 proteins “of interest” that interact with viruses. Next, he built an algorithm to scour genomic databases so he could compare the evolution of virus-interacting proteins to all the others. The results found that virus-interacting proteins absorb the biggest burden, but all other proteins are impacted, too.
Another article about this same study (published by Genetic Engineering & Biotechnology News) put it this way: “Since viruses hijack nearly every function of a host organism’s cells to replicate and spread, it makes sense that they would drive the evolution of the cellular machinery to a greater extent than other evolutionary pressures such as predation or environmental conditions. This study sheds light on some longstanding biological conundrums, such as why closely related species have evolved different machinery to perform identical cellular functions, like DNA replication or the production of membranes.”
Viruses are part of life. Not all are bad. Many catch a ride on living organisms and do no harm.
Viral ecologist Marilyn J. Roossinck thinks viruses are under-appreciated. She wrote the book, Virus: An Illustrated Guide to 101 Incredible Microbes (Princeton University Press, 2016). She also coauthored the article “Symbiosis: Viruses as Intimate Partners,” in the 2017 Annual Review of Virology.
We highly recommend this fascinating interview with Roossnick in Knowable Magazine.
Roossnick said she “fell in love” with viruses as an undergraduate student during a microbiology course. “I was amazed at the intricacy of their relationships with their hosts and I made a decision, at that moment, that I was going to be a virologist,” she said.
Viruses, she pointed out, are the most abundant and diverse beings on the planet—and they’re found everywhere.
“We probably still know only a small fraction of the viruses that exist, but we’re learning more every day,” she said.
Roossnick predicts that viruses will be seen as beneficial. For instance, there is work underway to see if viruses can get rid of bacteria that infect crops.
Viruses are part of life, she points out. They might be “remnants o