Darwin’s Surprise

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.

 

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8 Responses to Darwin’s Surprise

  1. jamesfan1 says:

    It is certainly surprising that these viruses that are long extinct relative to modernity are still affecting humans to this day. In response to the post’s notions of the evolutionary origins of the placenta caused by endogenous retroviruses in the germ cells as well as the protection from certain diseases that endogenous retroviruses provide, the fact that the general populace fear viruses as a whole is disappointing. Perhaps most see non-living particles that can take control of the basic unit of life akin to a zombie infection fantasy, and thus choose to avoid the topic of viruses entirely. Others may see viruses as an annoyance, to be combated with the wealth of vaccines that hospitals can employ. The main benefit of viruses that is constantly stressed in the article, an evolutionary force that provides pressure in selecting for fit organisms, is overlooked, mainly because, as the post points out, of the negative connotations of the word “virus.”

    However, even if viruses act as a driver of evolution, one cannot rest calmly and watch viruses continuously infect. One cannot forget that evolution can cause the downfall of a species if that species is not well-adapted enough for a specific threat. While retroviruses are beneficial in instances such as the placenta, they can still be harmful in cases such as HIV and thus must still be treated cautiously. Just as how retroviruses should not be considered inherently damaging, they also should not be instantly considered beneficial. Similar to the neutral nature of mutations, neither good nor bad, simply a change, a provirus injected by a retrovirus may prove to be helpful or harmful or neither.

  2. SanaM says:

    I disagree with your thought on the sentence ” Humans are descended from viruses as well as from apes” that is stated in the article. Although I feel that your points are valid, I feel that the intention of the author was not to say it literally. I think it may have conveyed that unintentionally. The way I understood the quote was that viruses and apes have aided in the evolution of the human species, which is, to an extent true. I do agree on your thoughts about the word “virus” carrying a negative connotation. I think that this article does an excellent job of clearing that connotation and opening the reader’s mind to exactly how beneficial viruses have been proved to be in evolution. For me, the fact that we have endogenous retroviruses is also calming but it does not necessarily calm my fears about other viruses that may pose a threat to the existence and current health of our species. I also agree that the placenta discussion was very fascinating and gave me more inclination to think of viruses as something more positive. I also agree on research on viruses that is progressive because I feel that by giving people the training and ability to conduct this type of important research, we are trusting them to do what is for the good of our species. I was a bit shocked when I first read about the re-creation of the polio viruses in animals and why it was reconstructed by the two scientists. I understand, from the researcher’s perspective, how fascinating and challenging it can be to prove something in science, but also believe in your “power trips” going overboard idea. I think the fact that small animals were infected with the re-created virus is concerning because it may mean that if this virus were to escape the lab, it could cause great harm to society.

  3. AreebA says:

    I agree with your comment about how Darwin would be surprised to know that humans may have evolved from viruses as well as from apes. To further your comment, I would like to say that Darwin would be thrilled to learn of the existence of viral DNA in the human genome. Darwin mostly studied the effects of the environment on the overall fitness of an organism in a species. Finding out that viruses can also affect the fitness of an organism would certainly “surprise” Darwin.
    Furthermore, the idea that the placenta may have evolved from a virus is certainly mind boggling. To think that the placenta, something that allows us to develop into a living organism, evolved from a virus, something that nowadays is considered deadly and life consuming, is truly remarkable.
    Also, I’d like to point out that the article talked about how when the scientists recreated the viruses, they made it so that the viruses would only be able to reproduce once. This shows that scientists can control the viruses to such an extent that it wouldn’t be deadly to the entire human population.

  4. kniedzwiadek says:

    I like that you focused on the positive side of viruses! I especially liked your statement, “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. ” I had a similar reaction after reading the article because we typically consider viruses to be bad. This reminds me of how the word “mutation” has a negative connotation, even though a mutation is nothing but a change, which can be either positive or negative. Granted, viruses deserve their negative connotation while mutations do not. Although viruses are certainly not pleasant to us, our ability to develop defenses against them has increased our fitness and allowed us to evolve into better adapted organisms.

    You also stated that, “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.” Although I agree that viruses have played a significant role in shaping our species in an evolutionary time frame, I also believe that a fear of viruses is justified when we have millions of people suffering from viruses such as HIV. Because of the negative impacts viruses have had on us historically, it is difficult to imagine how they could possibly serve any good purpose. However, millions of years from now, all humans could hypothetically be immune to HIV and there would be a new virus to worry about. So while I completely agree that viruses have served an important role in our evolution, it is important to note that viruses are still very dangerous. There is so much that we have yet to learn about them, and I think we need to be cautious before we decide that reviving extinct viruses should become a common method for studying current viruses.

  5. sasvoboda says:

    Although human’s have developed defenses against viruses in the past, I believe the real fear is that one or multiple viruses will be ferocious enough to wipe out the entire species. A virus that mutates and evolves at a rate that allows them to evade modern medical treatments but also keeps them functional could infect and kill most or all humans if it is spread quickly and widely. Relying on the hope that we will evolve quickly enough to protect ourselves against these viruses may be our downfall. Scientists like Harmit Malik may be the answer to our eminent demise.
    I completely agree that the resurrection of “extinct” or “dead” viruses is acceptable depending on the reasons for resurrection. Whether or not a reason is good enough is not something I can decide– it would require debate, philosophical evidence, and a lot of time to come to any real conclusion regarding this. However, because time is of the essence, I will say that I believe the resurrection of viruses for the purpose of bettering society and prolonging the survival of the human race without harming large amounts of living beings is acceptable. For the most part, scientists today that participate in the revival of these viruses follow strict protocol and are extremely cautious when working with their experiments so the likelihood of an outbreak that would harm humans and other sentient beings is slim. Testing these viruses with small animal models, on the other hand, is a very controversial issue. It would take a long time and a lot of discussion to determine whether or not the death of sheep is more or less important than the death of a human, so I can not take a side here.
    In my opinion, reading about Emerman and Malik’s reconstruction of the PtERV virus not only justifies the resurrection of viruses for the purpose of eliminating other more harmful viruses, but it gives me hope for the future. Other virologists and evolutionary geneticists will be able to study their experiments and hopefully gain insight as to how HIV can be neutralized with the help of proteins in the future and the general functioning of HIV as a retrovirus threatening humans with a potential to become an endogenous retrovirus.

  6. TonD says:

    I think the ultimate goal of the paleovirologists was not for the revival of the viruses, although it was an amazing feat, but rather to better understand viruses and better protect ourselves against current and future epidemics. Testing on small animals is harsh, but I think it is inevitable if we really want to protect ourselves. Think of the cost-benefit analysis. If scientists do not test their experiments on small animals first, how will they know what to do in a potentially grave situation pertaining to humans? There have been great feats in science and technology with the help of animal testing. I agree that it there can be cases where animals are mistreated, but I like to believe that professional and leading scientists of our world test them in a humane way and limit the amount of suffering if they have to die.

  7. FelissaH says:

    I definitely agree in terms of the role virus plays in the evolution of humans and perhaps other species. The article does lean a little bit to say that we have “descended” from virus. Due to this misleading wording of this statement, it could be inferred that we were once virus in our earliest forms of life. Though it could be true, it would seem unlikely due to the nature of the retrovirus, being one to infect and change the genomic structure of creatures. It is definitely more plausible to say that we were “altered” rather than “derived from.”

    I also agree about the terms of ethics that was displayed in the role of virus revival. I did not believe that the displayed of the resurfaced revival success was justified in the killing of animals, rodent or not. The talk of bioterrorism is something that people are afraid of due to the lack of care of killing other mammals. The advance technology used today to understand these diseases are the same the could possibly harm us if used incorrectly.

  8. RichardK says:

    I believe that there were big picture aspects that were being taken into account when the polio virus was revived. The polio virus was resurrected just to prove that it can be done, but it was merely a stepping stone to reviving viruses that may give us the knowledge to vaccinate against or cure modern viruses. Unfortunately, I believe testing on small animals is an inevitable step in this process of learning. Everything is merely hypothetical before testing and it is more difficult to test on humans than testing on other subjects similar to ourselves such as mice, chimpanzees, etc. There are gray lines where testing on animals could stray into animal cruelty, but I believe it is a necessary step in furthering mankind.

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