Darwin might find it surprising that the organism most at arms with humans, the most advanced species on the planet, are the lifeless viruses, the simplest carriers of genetic information. Darwin’s surprise is that endogenic retroviruses such as H.I.V. could very well be the strongest driving force behind evolution. For example, Heidmann and others suggest endogenic retroviruses play a role in characterizing mammals against other animals by fueling the development of the placenta (Specter). It is because of these advances that viruses can be thought of as “a major creative force” in our evolution (Villarreal). Viruses evolve along with us, as we are able to synthesize modified proteins that are not complimentary to the virus’s receptors, the virus finds ways to modify their receptors. Descent with modification absolutely applies to the infectors and the ones infected.
I found the mere fact that endogenic retroviruses consist of about 10% of our genome very surprising. It makes sense that viruses will have embedded their own DNA into ours if they are passed along the gametic germ cells. The concept that viruses can prove advantageous also makes sense as imbedded viruses would help us recognize and fight against new strains of similar viruses. It astounds me that the best possible way to find cures to the current most deadly viruses such as H.I.V. is to resurrect past endogenic retroviruses. Also, I find it interesting that the presence of an endogenic retrovirus can be something that divides two species, such as the human and the chimpanzee, apart.
The presence of viruses such as PtERV in the genomes of chimpanzees and gorillas help to explain why H.I.V. does not cause them harm. Being similar to H.I.V., PtERV allows these apes to recognize H.I.V., and prevent it from being lethal. Examining this evolutionary history gives us insight to our own genomes, and explains why H.I.V. is one of the biggest threats to us, but not to our closest relatives. When we diverged from our common ancestor with the chimpanzee, we could have either never been infected with PtERV, or those who were all died. We can look to endogenic retroviruses much like the fossil record, finding many commonalities among related organisms and the viruses in their genomes. In another example, the recently introduced koalas are susceptible to a virus that the southern island koalas are not. This gives scientists a great opportunity to witness evolution in action. This article has definitely turned my understanding of viruses upside down. I never could have imagined that viruses could increase fitness, and that they are such important parts of making a species distinct.
Such as with the benefits derived from stem cell research, I would absolutely be supportive of paleovirology and the practice of looking at the mechanisms of past viruses to help us understand and find cures for current ones. Scientists such as Heidmann and Malik are doing work to advance our species’ fitness. As Heidmann stated, “the phoenix virus sheds light on how H.I.V. operates, but, more than that, on how we operate, and how we evolved.” Doing this sort of research would kill two birds in one stone. We would not only be able to find cures to viral diseases faster, but also we would be able to better understand our history.