Darwin’s Surprise

In this article, Professor Weiss wrote that “If Charles Darwin reappeared today, he might be surprised to learn that humans are descended from viruses as well as from apes.” In addition to being surprised by the extent of his own theory, Darwin might also be surprised by the studies being conducted with retroviruses. Research such as that at the Oxford University and Fred Hutchinson Cancer Research Center, which gave support to Phoenix discoverer Thierry Heidmann’s claim that the retrovirus could tell us more about the evolution of our species, might be particularly vexing, as Darwinian principles claim that evolution takes time. The rapid mutation of Phoenix, H.I.V., and other retroviruses might seem particularly contrary to Darwin. Similarly, such concepts are probably surprising to the average reader, as Darwinian principles of evolution have, for the most part, remained an integral part of scientific education and foundation. This new evidence of rapidly evolving viruses, an “organism” which the scientific community cannot even determine is living or not, is therefore shocking, frightening, and, yes, surprising.

I was very surprised to discover that, while only 2% of our DNA codes for proteins, 8-10% codes for these (now “defeated by evolution”) retroviruses. What happens to the cells infected with retroviruses? I know HIV just tears apart the immune system cells, and I guess uses “vif” to make copies of itself, so what do other retroviruses do to the body? Why don’t they cause frame shift mutations that could alert the immune system to a problem with the cell? It’s just unfathomable that there’s all this “junk” built into the most important informational construct of all organisms. I was also surprised that scientists like John Coffin, and other scientific group, were (at least originally) against work such as Dr. Heidmann’s, and the work of the State University of New York at Stony Brook. “Paleovirology” that reconstructs old retroviruses, or, in the case of the State University, “builds” current ones, are incredible feats of scientific achievement and could provide multitudes of information in many different fields including immunology, evolutionary science, pharmacology, even bioterrorism prevention. With the proper precautions, I don’t see why there was such a concern over fear and suspicion.

The article explains that, based on current research, these viruses and retroviruses have played a significant role in human evolutionary development and history. It is proposed that “without endogenous retroviruses mammals might have never developed a placenta” which protects a growing offspring from retroviruses while also enabling it to access nutrients from the mother.  This also may have led to live births, “one of the hallmarks of our evolutionary success.” Also, the discovery of reverse transcriptase may explain certain cancer’s rapid replication in our bodies and explains the transmission of infections like H.I.V. This suggests that viruses have not only caused harmful developments in mammals, but initiated selection for some of the most defining mammalian characteristics there are, namely the placenta and live births. Syncytin, the protein layer of the placenta which shares characteristic mechanisms to a retrovirus, provides the biggest evidence of beneficial selection and evolutionary significance caused by retroviruses , but I have to think that there are more than just that. These are a type of virus that make up 8-10% of our DNA: surely we have just begun to uncover the evolutionary significance they may have played in our development.

Revival of retroviruses allows scientists to study them thoroughly, dissecting their molecular components or finding patterns in genetic development. This level of in-depth knowledge of these retroviruses could provide us with a more complete genetic history, such as with research like this: “Anthropologists and biologists have used [Retroviruses] to investigate not only the lineage of primates but the relationships among animals—dogs, jackals, wolves, and foxes, for example—and also to test whether similar organisms may in fact be unrelated.” Furthermore, research could be done in creating vaccines for current retroviruses, such as those which are suspected to assist in cancerous cell reproduction and HIV infection perpetuation. For example, now that we know the AIDS gene vif “does nothing but block a protein whose sole job is to stop the virus from making copies of itself”, perhaps immunologists may someday be able to create a medicine or vaccine which counteracts this gene. Research conducted through “reviving” a virus has already seen incredible discovery. Harmit Malik and Michael Emerman’s discovery of the “pterv” retrovirus and its implications concerning human evolution – namely that it might be the reason HIV is so deadly to us and not to genetically similar primates- is an astounding discovery that could not have occurred without the revival of the retrovirus. Overall, the investigation into these retroviruses appears to be leading to an increase in scientific communication and discovery as a whole, as evinced by The Hutchinson Center, which “encourages its research scientists to collaborate with colleagues in seemingly unrelated fields.” Furthermore, the perpetuation of these great leaps and bounds in science can be seen in such shattering discoveries as Aris Katzourakis’s “relik”, the lentivirus discovered in the European Rabbit, which could provide the link which shows how HIV became endogenous.The scientific fervor and excitement generated by the topic is akin to a pervasive energy that has been seen throughout history as giving rise to some of the greatest scientific achievements ever. This is the same feeling which surrounded the completion of the human genome project or the protein v. DNA debate, and this too can only result in further understanding of the world.

 

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One Response to Darwin’s Surprise

  1. alindsey9 says:

    It’s interesting that “LilyB” actually analyzed the title, which I had not thought about in any depth. The title “Darwin’s Surprise” is actually pretty ironic: yes, Darwin would be surprised that retroviruses are featured so heavily in human DNA, but to even understand this new discovery, he would first have to be given many more surprises about the general structure and even existence of DNA and viruses. He knew that some genetic material was passed down, but because of his time period, he never ventured into the realm of microevolution. So really, referencing Darwin in this article is a bit of a strange comparison- it’s just that he is always the go-to guy on anything evolutionary.

    More on surprises, “LilyB” remarked on her astonishment that there was so much junk DNA in the human genome, and then went on to talk about the purpose of viral DNA encompassed in human DNA. It occurs to me that since biologists assume all attributes of organisms have evolved from a common ancestor because they are advantageous, we really shouldn’t be so surprised that junk DNA can have advantages and has evolved for a reason. We also shouldn’t be so surprised that viral DNA has proved important to humans. Since viruses aren’t truly alive, they have no real reason to pass on their genes if the genes don’t affect something living.

    Additionally, LilyB’s last point was very thought-provoking. The “scientific fervor” observed when the structure of DNA was discovered, or for any of the elegant experiments, was probably not fully realized while they were being conducted. The people of the times that revolutionary scientific discoveries were being made didn’t necessarily realize that history was in the making, even though it certainly was. As far as we know, this research and the experiments that will follow it up could lead to some of the most important discoveries ever made.

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