Yes, Viruses are Indeed Living

MVHS students may look back at freshman year biology with fond memories of pain, suffering, and lack of sleep. One of the most foundational units was dedicated to teaching students how to identify objects as living or non-living. A rock cannot grow, reproduce, respond to external stimuli, or use energy and thus, they are non-living. A tree, on the other hand, follows these properties, and is classified as living. The standards to decide if the rock or tree are living or nonliving are called the seven characteristics of life.

Viruses are the blind spots in biology’s vision. Do they follow these characteristics? Are they living or nonliving? This question has long been a cause of confusion for students and even scientists, but the long overdue answer has finally arrived. A new study published on Sep. 25 sheds light on viruses and confirms that they are, indeed, living organisms.

 

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Coming to a conclusion

Students were previously taught that viruses did not strictly fit the characteristics of life. They don’t technically metabolize, and they don’t reproduce the way other living organisms do.

According to Arshan Nasir, University of Illinois graduate who contributed to the new study, the reason why it took scientists so long to come to this conclusion was their definition of the word “life”. By broadening the definition to include using other bodies as a means of acquiring energy and reproducing, viruses can be classified as living.

“[Viruses] simply have an atypical mode of living that is slightly different from ours,” Nasir said. “They are not fully independent.”

By looking at the past, and how viruses evolved, scientists discovered that viruses share properties with cells. One of the most significant shared properties is protein folds.

Scientists found that cells and viruses shared 442 protein folds, and 66 protein folds were only found in viruses. Gustavo Caetano-Anolles, a professor at Carl R. Woese Institute for Genomic Biology, believes that this shows that viruses branched out from cells and evolved alongside them.

“The mere fact of the existence of a universal biology unifying viruses and cells now justifies the construction of a Tree of Life that embraces viruses side by side with cells,” Caetano-Anolles said.

 

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The reason why they appear so different lies in the nature of evolution. Viruses in the past did not have a need for many cellular qualities. They were able to survive without them by benefiting from just interacting with cells. The evolution of viruses was the starting point and ending point of their classification, and scientists are now looking for ways to use their new discovery.


Applying new knowledge

For students at MVHS, this discovery changes the foundation of material taught in biology classes. Sophomore Krithika Rao remembers the ambiguity with classifying viruses in her freshman biology class.

“I remember writing a claim, evidence and reasoning and discussing our conclusions,” Rao said. “I feel like now they’re [classified as] living, there’s no more room for debate.”

As a current student in biology, Freshman Jenny Chen believes this shifts emphasis away from the seven characteristics of life.

“[The discovery] changes that you don’t really need characteristics of life to be classified as living,” Chen said.

With the new discovery in mind, scientists now have a goal to apply this information to combatting viruses in the medical world. Currently, antiviral drugs exist to help fight the flu. These drugs bind to an enzyme in the virus to prevent it from releasing the parts that harm your body. However, antiviral drugs are not ideal, and tend to cause side-effects. Andrew Camilli, a professor of molecular biology and microbiology at Tufts University, concluded that viruses can inherit immune systems from a host cell they infect. This means that cells won’t be able to recognize viruses as intruders, which then allows the viruses to infect the cells.

Although the new classification of viruses was a breakthrough, the life cycle and evolution are still being researched. There are many questions that still remain unanswered. Can antibiotics, previously only used for bacteria, now be used for viruses? Can we now ask if viruses can be killed without being scientifically inaccurate?

And of course, most importantly, can freshman biology students write on a test that viruses are living and not lose points?

Students may move on from biology class, but for scientists, the job never ends. With a new goal of innovation in the medical field, scientists move forward with this discovery and continue to question, research, and create.