Viruses: “Genetic Parasites” or “Unseen Creator”?

Charles Darwin’s 19th Century technology allowed him to study the beaks of various finches in the Galapagos Islands, and in the process he derived natural selection as a mechanism for evolution. With the invention of the microscope many years later, scientists have made shocking new discoveries related to evolutionary history. The article, Darwin’s Surprise, focuses on research that demonstrates viruses have a role in modifying genomes. Darwin would never have suspected that viruses, packages of genetic material encapsulated in a protein coat, could evolve by natural selection. After all, being unable to replicate without a host cell renders these viruses non-living in the eyes of science, and the environment was supposed to act on living organisms. The fact that some of these endogenous viruses “could take its place in the blueprint of our species, passed from mother to child, and from one generation to the next, much like a gene for eye color or asthma” (3) would probably be equally astonishing to Darwin. Nevertheless, endogenous viruses are still subject to the same pressures that drive changes and can be used as evidence in mapping out phylogenic trees. The difference is but a slight modification to Darwin’s understanding of evolving organisms by shifting his perspective from a macroscopic to microscopic level.

Even to a person of the modern world, where the internet hosts answers to questions rarely asked, the complexities behind endogenous viruses and evolution are understood by few. Perhaps a biology class lecture would draw out the connection between introns, the non-coding regions of DNA deemed junk, are actually remnants of the incorporated viral DNA now in our genome. At first many are startled to learn that information from the viruses, commonly known to be responsible for sick days and tedious pains, make up  our genome where “eight per cent, however, is composed of broken and disabled retroviruses, which millions of years ago, managed to embed themselves in the DNA of our ancestors” (4). These viruses are not just invaders seeking resources for replication, but also clues to unveiling the mysteries of our genetic code. By understanding how these pieces interact with the rest of our genome, scientists may be many steps closer to realizing the importance of introns and devising a way to visualize how deadly viruses have become a simple part of our cells.

Interestingly enough, these viruses are also most likely how mammals evolved to have adaptations like the placenta as “Heidmann and others have suggested that without endogenous retroviruses mammals might never have developed a placenta, which protects the fetus and gives it time to mature”(11). The benefits of having the nutritious environment free of generated waste would aid in the development of a more complex brain structure, in turn allowing mammals and humans a wider range of abilities. Viruses are helping to fill in blanks in evolutionary history to explain how some of our functions made it to present day. Researchers have also shown that extinct viruses of the past impact our vulnerability to viruses still living. According to the article, as “humans developed an effective defense against one virus, pterv, at about the time we split off from the chimps… we were left vulnerable to a new one, HIV”, suggesting that studying the changes will one day allow us to manipulate which diseases can affect us. This could have many new directions for the field of virology and disease control in human populations.

While science is a wonderful tool responsible for saving lives, making processes more efficient, and accumulating information, it is possibly humanity’s strongest weapon. Reviving dead viruses may unfold our evolutionary history and catalyze the creation of successful vaccines, but just as easily could launch a new branch of bio terrorism that we currently have no means to defend against. As such, researchers should proceed with much caution in their experiments, ensuring that negative consequences are kept at a minimum and data  is secured from those with ill intentions. Laboratories should also take protective measures against any experimental accidents that could endanger the human population. What are the effects of bringing back these viruses? Just how strong is the human immune system against those viral particles it hasn’t faced in generations? Hopefully we won’t have to find out after a serious epidemic has decimated the world. Life has always managed to find a way to come back, and such studies could eventually prove beneficial in modeling viral adaptation, improving methods of  biomedical engineering, and satisfying the curiosity of eager young minds.

 

 

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