Endogenous Retroviruses and Human Evolution

April 1, 2012

   Endogenous Retroviruses and Human Evolution

Contributed by: Chris Harrison (University of Texas)

In The Descent of Man and Selection in Relation to Sex, Charles Darwin first suggested that humans shared a common ancestor with the great apes. Now, over a century later, the fruits of molecular biology and comparative genomics have corroborated Darwin’s hypothesis to a stunning degree.

Endogenous Retroviruses:

Due to long statistical odds, retroviruses usually infect the DNA of somatic cells and are dubbed exogenous. In the event that a virus integrates itself into a portion of germline DNA, it becomes endogenous and is subject to normal Mendelian inheritance. The co-evolution of the virus and its host entails that the host’s progeny will inherit the virus.

Because of their vertical inheritance, finding the same ERV in two different species offers irrefutable evidence of common ancestry. Genome wide sweeps of the human and chimpanzee genome reveal that we share 7 ERVs with Pan troglodytes, the common chimp (Bonner et al. 1982; Sverdlov 2000; Dangel et al.1995; Svensson et al. 1995; Kjellman et al. 1999; Lebedev et al. 2000; Sverdlov 2000).

This image (courtesy Lavie et al. 2004) confirms the presence of HERV-K(HML-5) homologous sequences in various primate species:


Species abbreviations are as follows:

For Hominoidea, Hsa is Homo

, Ptr is Pan troglodytes, Ppy is Pongo pygmaeus, and Hla is Hylobates lar

For Old World primates, Cgu is Colobus guereza, Msp is Mandrillus sphinx, and Mmu is Macaca mulatta

For New World primates, Ssc is Saimiri sciureus, Cja is Callithrix jacchus, and Ase is Alouatta seniculus

For prosimians, Nyc is Nycticebus coucang.

Here, we see that HERV-K is present in numerous primate species, indicating that HERV-K was fixed in an ancestral genome whose descendents include all the above species, including Homo sapiens.

The shared ERVs between humans and chimpanzees (as well as other primates) represent one of the most convincing and intriguing arguments for the descent of man. Fossils and comparative anatomy can take us far, but retroviral evidence chronicles the evolutionary history of our species in unprecedented detail.


Bonner, T. I., C. O'Connell, et al. (1982) "Cloned endogenous retroviral sequences from human DNA." PNAS 79: 4709.

Dangel, A. W., B. J. Baker, et al. (1995) "Complement component C4 gene intron 9 as a phylogenetic marker for primates: long terminal repeats of the endogenous retrovirus ERV-K(C4) are a molecular clock of evolution." Immunogenetics 42:41-52.

Kjellman, C., H. O. Sjogren, et al. (1999) "HERV-F, a new group of human endogenous retrovirus sequences." Journal of General Virology 80: 2383.

Lavie L, Medstrand P, Schempp W, Meese E, Mayer J. Human endogenous retrovirus family HERV-K(HML-5): status, evolution, and reconstruction of an ancient betaretrovirus in the human genome. J Virol. 2004;78:8788–8798. doi:10.1128/JVI.78.16.8788-8798.2004.

Lebedev, Y. B., Belonovitch, O. S., Zybrova, N. V, Khil, P. P., Kurdyukov, S.G., Vinogradova, T.V., Hunsmann, G., and Sverdlov, E. D. (2000) "Differencesin HERV-K LTR insertions in orthologous loci of humans and great apes." Gene 247: 265-277.

Svensson, A. C., N. Setterblad, et al. (1995) "Primate DRB genes from the DR3 and DR8 haplotypes contain ERV9 LTR elements at identical positions." Immunogenetics 41: 74.

Sverdlov, E. D. (2000) "Retroviruses and primate evolution." BioEssays 22:161-171.


Evolution and the Rutgers Community

February 22, 2007

Submitted by Dr. David Howe

Why has there been little interest in contributing to this blog so far? This is interesting in itself. Perhaps the Rutgers audience is more accepting of evolution than the rest of the US (33rd of 34, just above Turkey; see Miller et al., 2006, Science 313). People not accepting of evolution (fundamentalist Christians; people with less genetic and scientific literacy) may be hesitant to speak their beliefs in NJ. Maybe people don’t believe that lack of acceptance of evolution is an issue, or that science in general is that important (strange for citizens of the most scientifically and technologically productive nation).

To me, lack of acceptance is symptomatic of more serious conditions: politicization of science (witness the debates on global warming, environmental protection, sex education, stem cells, evidence for WMD, creationism vs. evolution in schools); people’s poor understanding of science (many Americans recognize concepts, but their understanding of them may be weak). These factors can lead to poor decision making, given the complexity of problems we face (potential pandemics, pharmaceuticals in our water, global warming, nuclear proliferation, and so on). Collectively, individual decisions can have society-wide effects. Many problems may not be immediately or acutely felt and thus may not be taken seriously. To this, add fear, inefficacy, and unwillingness to change and we have created a society poorly equipped to move ahead. We can overcome this inertia, and I take this blog as evidence.


Opening up

February 20, 2007

After some contemplation and encouragement, I’ve decided to open Darwin’s Beagles up to the larger Rutgers community, including graduate students, post docs, and faculty members. Contributors from other schools are still encouraged to submit, hopefully spurring chapters of Darwin’s Beagles in different locations across the country, but I’ll deal with that when and if it arises. In any event, please, link to us or help spread the word. I happened across Cornell’s intelligent design club, IDEA, today, wondering how so many of the “top” schools in the nation could have active intelligent design groups but no groups based in empirical science to answer their claims. Perhaps there are, but it is becoming increasingly important for scientists to speak up about evolution and it’s importance to biology, and I’m hoping to start that change right here and now at Rutgers. I’m still awaiting submissions, so as always please contact me at b_switek@yahoo.com to contribute.


Darwin’s Beagles now on Facebook!

February 10, 2007

So far the response to Darwin’s Beagles has been, well, underwhelming, so I’ve launched a new Facebook group to hopefully get some members/contributors. If you want to add it on your profile, you can find it here.


Announcing Darwin’s Beagles!

February 5, 2007

Hello everyone, and welcome to a brand new blog meant to jump-start the discussion of evolution among Rutgers University undergraduates. About a year ago I was taking a course that required me to teach 5th grade public elementary school students, but upon electing to teach a lesson on whale evolution I was told that the topic was far too controversial to be incorporated in the classroom. Growing up accepting evolution as scientific fact, I was put-off with the censorship of my lesson plan and so I started reading every book on the topic of evolution, intelligent design, and creationism I could get my hands on. Indeed, the first book I picked up was Jonathan Wells’ polemic Icons of Evolution, and instead of turning me against evolution it made me dive further into the evidence and debate surrounding the constant changes of life since it first arose on the planet.

Now 9 months after I first started reading Icons the debate seems just as hot as ever, creationists still fuming over the Kitzmiller vs. Dover and evolutionists attempting to take the offensive in order to educate the public about what evolution is. This blog (hopefully) will be part of the “evolution intitative,” providing concerned undergraduates submit their thoughts, contemplations, and understandings of evolution and the evolving controversy that surrounds it. Huxley may have been “Darwin’s Bulldog” and Dawkins “Darwin’s Rottweiler,” but we are still just pups by comparison, hence the name “Darwin’s Beagles.” Although this space will be open to any undergraduate or up contributions (at the discernment of the editors, of course) this hopefully will be a website for and by the concerned Rutgers undergraduate community. New Jersey has always been considered a “Blue State” where conflicts over evolution have typically been out of the public eye, but with the recent events that have unfolded in Kearny, as well as school systems quietly banning evolution from classrooms New Jersey is most certainly not as secure in science as was once supposed. I have grown tired with the apathy that surrounds me involving this subject, many people choosing simply not to think about it and engage in relativism rather than face the issues at hand. Everyone is entitled to their beliefs, but not all beliefs or criticisms are correct, and it is the aim of this blog to attempt to reach out to my fellow undergraduates who are concerned with the slackening state of science in the United States and elsewhere. Hopefully this blog should fully launch with articles from various students in the coming weeks, but until such time please view my own writings at http://laelaps.wordpress.com. Best regards,

Brian Switek
5th year Ecology & Evolution undergrad
Rutgers University, Cook College, NJ