Darwin’s Surprise

This article is appropriately named “Darwin’s Surprise” because of the likely reaction he would have had to the findings of Heidmann, Temin, and the like; “humans are descended from viruses as well as from apes”. Endogenous viruses are an integral part of our genome, with 8% of our genomes being composed of fossilized or otherwise disabled retroviruses. While these genomes are still considered “junk” DNA, they are very important in unraveling and understanding the evolution of humans. Darwin probably never would have imagined that tiny, lifeless molecules that wreaked havoc on prehistoric humanoids were actually a big factor in our evolution, with some scientists today speculating that, without the viruses, we would not have evolved the same way.

I had no idea we were comprised of bits and pieces of past retroviruses that had plagued our ancestors. I knew some viruses embedded themselves in host DNA, but I didn’t know ancient ones were present across the human race. Also, the fact that these bits of retroviruses could potentially have positive effects on humans seems like an oxymoron, but the article was fascinating in that it explained possible theories for this as well. I knew that scientists could reconstruct past viruses from outbreaks (like the article mentioned), but I wasn’t quite sure of the exact method.

The article says that, as   retroviruses became a part of the genome in the germline cells of our ancestors, they were passed along to the rest of the human race and were eventually disabled, either through immune response or too many mutations that render it incapable of carrying out its function. Some of these bits and pieces still carry out minimal function, just with no effects to the host whatsoever. However, these endogenous retrovirus bits can have effects on other viruses we’re exposed to, protecting us from them. Some of the scientists mentioned, including Heidmann, believed that humans would not have evolved the same way without the help of these viruses; i.e., the development of the placenta seemed to be a direct result of these endogenous viruses. After reading this article, I have a whole new perspective. Say ‘virus’, and the first thing many people think of is illness and death, not human genes and AIDS vaccine research. The amount of complexity one little molecule has and its effect on the human race is amazing, and the fact that endogenous retroviruses may one day lead to finding a cure for AIDS is phenomenal.

I think the idea of reviving dead viruses is more helpful than scary. I have seen my fair share of sci-fi movies/shows where a synthesized virus used in biochemical warfare kills off half the planet (or makes them into zombies). While this is a far stretch, there is a bit of reality, as seen with the State University of New York at Stony Brook students who made a polio virus “to prove it could be done”. However, the grand majority of revivals are being done in labs with strict ethics and one-generation termination sequences to prevent anything from going awry. These controlled experiments are what brought about the discoveries about how some endogenous viruses act as beacons to HIV infected cells, allowing them to be terminated. The amount of research and prevention of further retrovirus outbreaks that these ‘revivals’ are responsible for far outweigh any other concerns.

 

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3 Responses to Darwin’s Surprise

  1. GloriaE says:

    This all brings me back to in class, when Ms.Ortiz was emphasizing that just because certain portions of DNA seem in excess does not mean they aren’t important. With the acknowledgment that 8% of our DNA is made up of disabled retroviruses, I have pieced together why.
    The quote used at the beginning of this post drew my attention, as it says “humans are descended from viruses as well as from apes.” This puts an emphasis on viruses as a main contributor to the evolutionary history of humans, and equating the two is almost drawing the attention to this new idea in a different way. Most people think of apes as the reason of why we are today, but this article definitely added a word to my vocabulary when speaking of human evolution. The placental example truly draws this connection to viruses closer, making it easier to believe and more imperative to study.
    In retrospect, it makes sense that viruses can contribute to evolution, but this article spins it in a new way. At first, it was just survival of the fittest, an example that emphasizes the mainly phenotypic advantageous traits of an organism. Now, with the incorporation of viral DNA into the mix, it brings it down to a more genotypic level. I agree with your stance on the complexity of viruses, and since finishing the article, I have started to understand the true two-sided nature of it all.

  2. sjrule says:

    In the back of my head I can’t help but wonder if some of those pieces of viruses just have a longer latency period then our lifetimes will allow. I also totally agree with your last paragraph, it is a bit scare to think of the power we hold when we can recreate potential deadly viruses. Not to mention one little mutation and all the sudden there is some sort of plague on our hands. In a way our lives are in those lab techs hands. In a away we acted just like the bacteria we mentioned in class. We were exposed to the viruses in the past, those who had mutation that let the viruses not effect them passed it on. Then centenaries later many of us are no longer effected as well because the traits (in this case the fragments) were passed on to us.

  3. AliM says:

    I was happy to see I was not the only one whose mind jumped to science fiction when reading this article! “Darwin’s Surprise” itself admits that the experiments it discusses call to mind “Frankenstein’s monster and Jurassic Park,” but in our current cultural milieu, the idea of the virus conjures up much, much more than that. With a new swine flu craze flaring up year after year and movies like Resident Evil and 28 Days Later consistently earning millions at the box office, it is clear our culture is utterly terrified of viruses. In many cases, we are not wrong to be, as sicknesses caused by viruses kill many, many people every year. However, I agree with you that lab environments are not the places where people need to be afraid of them! The precautions taken by most scientists of good repute should be enough to convince people that there is nothing to worry about, and as you discussed, the benefits revival experiments could give to our society are enormous. I worry that people are afraid of things they cannot control, like the seemingly unstoppable power of viruses, and that the movies and TV shows of today take advantage of these fears while escalating them. The fact that simple ignorance could cause unease about experiments that could help us control the very things we fear is scarier than any virus. I think it’s very important to keep affirming the upsides to these experiments so unwarranted fear does not prevent funding and other support from getting to them–which is why I appreciated a comment like yours that could see past those creepy zombie movies and in to a brighter future!

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