The article focuses on the possibility that humans could have evolved from viruses. The fact that that eight percent of the human genome is comprised of endogenous retroviruses highlights the evolutionary historical significance of the viruses in shaping the species. If the retroviruses infected the germ-line cells, they were carried along in the human species from generation to generation and theii perpetuation is existence of evolutionary advantage. The article is labelled Darwin’s surprise because Darwin wrote about the evolution of different species. He reasoned that organisms have an ancestral common ancestor and some species diverged in phylogenetic trees more recently which is why they are similar. Darwin, then, if he found out about the research pertaining to endogenous retroviruses in the human genome and their relatedness to human history, he would be surprised to accept that humans are “descended from viruses as well as from apes” according to Robin Weiss. I don’t really agree completely with that sentence though. Humans didn’t descend from apes; rather the two species had a recent common ancestor. Also, humans didn’t descend from viruses, but viruses were environmental factors that influenced the evolution of humans. The presence of endogenous retroviruses that give information “millions of years into the past” thereby providing convincing energy of evolution.
The most surprising piece of information that I learned from this lab is that eight percent of the human genome is made up of endogenous retroviruses. When we talk in class about noncoding DNA and introns, we never really talk about where this DNA came from. It was really surprising to me then that eight percent of the genome was made up of broken down fragments of retroviruses. The word “virus” has a negative connotation in today’s society, so it was really surprising that it was benign and sometimes even beneficial for humans to have retroviruses in their DNA. For example, the article talks about the placenta as being initially a “parasite”, but eventually through evolution it became one of the reasons for the rise of mammals since the increased nutrition transmission from mother to offspring led to mammals having increased brain size. I was so unused to hearing about viruses in anything in a negative light that this article’s view of them being essential parts of human history and even beneficial in the rise of mammals through leading to the placenta.
Retroviruses convert RNA to DNA in the host cell contrary to the “central dogma of life” through reverse transcriptase. The viral DNA then “becomes part of the cell forever.” Through any process of cell division, the viral DNA will be replicated along with the cell. If in a human, a retrovirus infects a gametic cell, the retrovithe rus would become a human gene passed from generation to generation. The “junk DNA” is indicative of battling between infective retroviruses and species over millions of years. Eventually, evolution triumphed as the viruses probably either mutated too many times or humans became resistant to the virus. The viral DNA then became inert, but it stayed in our human DNA. Therefore, the endogenous viruses show the millions of years of the evolution of human species. Because ten percent of the human genome is retroviruses, According to Paul Bieniasz, “they [viruses] played a major role in our evolution” becuase they comprise ten percent of our DNA and we developed defenses against the viruses. These defenses indicate that viruses like H.I.V. that particularly damage human populations have existed before and we have evolved resistances against them. The evolution of these resistances culminate in the human species as it is today and is evidenced through the endogenous DNA. To me, this is extremely calming. Many people have real fear of viruses being the downfall of the human species, but it is clear from evolutionary history that our species has battled and triumphed over viruses time and time again. Also, the fact that the retroviruses led to the development of the mammalian placenta completely changed by perception of viruses being negative.
The resurrection of “dead” viruses to me is really only acceptable depending on the purpose of the revival. The scientists at Stone University who revived the polio virus and used it to test the crippling effects on small animals is completely unethical to me because their purpose was solely to prove that the virus could be revised. I am more open to the idea of science reviving viruses is ethical when the revival is being used to try to understand a related, modern day virus and attempt to make a vaccine. I do not believe that it is ethical to use revival as a means of reconstructing a virus for the simple reason for saving money by making the virus be able to infect “small animals” that are more cost-effective to test on. Basically, I don’t believe that the concept itself is wrong if it is used for progressive purposes, but I do think that there has to be careful consideration before reviving a virus just because scientists could get on power trips with the idea of reviving dead things. There is always the risk of the virus getting out of the labaratoroy and spreading into the general populous.