Is the virus alive? Viruses like the new coronavirus seem to have a terrifyingly efficient mechanism for self-replication, suggesting a will to survive. How could such a thing with a will to live not be alive? Why is a seemingly simple biological question sparking fierce debate among scientists?
On December 26, 2022, the American Salon website published an article titled “Do viruses have life?” Why Seemingly Simple Questions Spark Scientists’ Fierce Debate’ article. Its content is excerpted as follows:
Is the virus alive? Why is a seemingly simple biological question sparking fierce debate among scientists? By some criteria, viruses fit the basic definition of “life”; by others, they don’t.
In fact, some biologists—even most biologists—don’t think viruses should be considered alive.
Why is this so? After all, viruses like the new coronavirus seem to have a terrifyingly efficient mechanism for self-replication, suggesting a will to survive. How could such a thing with a will to live not be alive? The
Fundamental Question The question of whether viruses should be considered “living” turns out to be one of the most fundamental questions in modern biology.
Even today, scientists don’t have a concrete answer.
“There’s no single, consistent definition of life, and I suspect there isn’t a fully satisfactory definition at all,” said Dr. Eugene Cornyn, Distinguished Research Fellow, head of the Evolutionary Genomes Group at the National Institutes of Health.
”According to some accounts, viruses make up the vast majority of the biomass on Earth. So, I think they’re alive.” On these issues, scientists do agree: Viruses are biological entities with a protein Contains nucleic acid molecules (such as DNA or RNA) inside. To function and reproduce properly, viruses need to infect living cells and assimilate their genetic material. Viruses have played a huge role in the evolution of life and even human evolution. Sometimes, after infecting the human body, viruses leave fragments of genetic material in our DNA. An estimated 8% of the human genome consists of viral genetic material. Viruses we’ve been infected with at some point have remnants in our DNA, and those remnants are protective.
In considering whether these tiny protein clumps, as well as RNA or DNA, are technically alive, Corning defines it this way: “Life is a self-replicating system of chemical reactions endowed with a specialized, replicating memory storage facility , which directs the formation of the components of the system.”
Opinions vary The essential feature of this definition proposed by
Corning is that it encompasses all life forms, including memory storage (genomes, replicating genes) and metabolic networks (cells, regenerators) . If his definition is correct, then this would mean that the virus cannot be considered alive.
“A virus is a pure replica that is completely dependent on the host (cell) for metabolism. By this definition, a virus does not qualify as a life form,” Corning said. Dr. Jason Sheppard, an associate professor of neurobiology at the University of Utah School of Medicine,
disagrees Ning’s assessment of whether the virus is alive or not. “It’s a classic question in biology, and the classic definition is that something is alive if it replicates, grows, and responds to external stimuli,” Shepard said. “The reason why people don’t think viruses are alive is because They are parasitic organisms that require a host cell to replicate.”
At the center of each viral protein coat, however, is the genetic material that is either DNA or RNA, the molecule that creates humans.
Shepard also said: “Some (viruses) are very sophisticated machines that are very successful at reproducing themselves. In fact, according to some accounts, the vast majority of the biomass of the earth is composed of viruses. So, I think they are Alive.” Tracy
Goldstein, Ph.D., associate director of the Institute for Integrative Health at the University of California, Davis, and a professor in the Department of Pathology, Immunology and Microbiology, also believes the virus is alive. She described viruses as “endoparasites” that should be considered alive, but “they don’t have the ability to live independently”.
“Most viruses can survive for a short period of time outside the cell, like herpes, influenza, etc., can survive on surfaces,” Goldstein said. “In my opinion, if they can survive and replicate in the cell, they are alive. Because viruses are fundamentally parasitic, it is helpful to understand viruses through a similar framework used to understand other parasites.”
Unsolved “Parasites are viewed in many different ways,”
Goldstein said. Similarly with plants, we see species like orchids or mosses that depend on other plants for nutrients to survive, yet they are still considered alive. People have different ideas about how functional they are or how they relate to the world definition, but ultimately, these plants are still considered alive.”
In contrast, Dr. Stanley Perlman, a pediatrician and professor of microbiology and immunology at the University of Iowa, strongly disagrees with the idea that viruses are alive.
“Viruses can’t grow outside of infected cells, so I don’t think they’re alive, ” Perlman said. “The problem is that there are some pathogens that require mammalian cells to replicate and are considered alive.” As more is learned about viruses, the case for classifying them as live becomes stronger. For his part, Shepard expressed excitement about the discovery of so-called “giant viruses” larger than bacteria, arguing that “if your definition of life is that they should be able to replicate themselves,” then that problem doesn’t exist, because that is “verifiable”. At the same time, “no known virus has been shown to do this,” meaning the question is currently an open question at best.
Corning believes that it is impossible for us to make a clear definition of life and to give a completely objective and tenable answer to the question of “whether the virus is alive or not”. There cannot be any experiment or rigorous theory to address these questions. We can only look for the most useful and consistent solutions.
