Viruses have a pretty bad rap. In literature, a virus is a “corrupting influence,” while in the technological world, antivirus software is a must-have for any device. The Latin word “virus,” borrowed directly by English, originally means “poison.”
In all fairness, the infamy viruses have received isn’t undeserved. They are the original parasites, hijacking healthy cells to reproduce more qualmless hijackers. As the article states, “nothing—not even the Plague—has posed a more persistent threat to humanity than viral diseases.” Indeed, many spelled death for those infected up until the age of vaccination and have been nothing but menaces to our kind.
Or so we thought.
With the knowledge we’ve acquired in the last couple decades, not only do we have nuanced understanding of their vital role in all organisms’ evolution, but we can also stop calling the war against viruses an “us against them” conflict: viruses are a part of us. Disabled retroviruses lie within us like battle scars of “molecular battles that raged for generations.” I was shocked to learn this, for it meant that the inefficient noncoding DNA sequences are actually markers of evolution. This article suggests that we truly would not be who we are, in many ways, without viruses.
And that, the fact that retrovirus agents of the environment directly interacted with us to spur our evolution, is Darwin’s surprise; but I can’t say I’m too surprised.
It only makes sense. Everything I’ve learned about human biology and some of our species’ oddities has come to a head.
My sex ed teacher in 7th grade told our class that the most parasitic creatures in the world are babies, followed by adolescents. The second was (probably) sarcastic, but he presented sound logic for his first point: babies drain their mothers (the host) of nutrients, oxygen, and energy for nine months on average, only to be born and demand more time, energy, and attention as infants. My humanities teacher independently arrived at this conclusion and informed our class that babies are manipulative creatures that are adept and willing to do anything they can to get whatever they want.
Exaggerations, of course, by both, but I was absolutely shocked that this article corroborated their point: placentas are believed to be the result of endogenous retroviruses infecting an egg cell, an infection that proved to be advantageous to us. From cell division to protein production, emerging research on viruses proposes that these kinds of chance improvements (or changes to) our functions have defined and refined our evolutionary processes. This has completely revolutionized my understanding of viruses: a healthy dose of “poison” never hurt anybody.
In reality, viruses are hotbeds of mutation and variation, so it works out well that we have had run-ins with them so often because it meant that there was another source of the raw material required for evolution. For this reason, it is absolutely necessary for us to revive dead viruses, for these are the viruses that have infected our germ-line cells and probably had effects on our bodily processes that we have yet to discover. This must be done as it was done in the article, where scientists limit viruses to reproducing once. However, it is clear that in the enigma that is our genome, virology and paleovirology hold the answers to many dire questions unanswerable by our natural genome and epigenetics alone.