Friday, September 04, 2009

Resources for a Lesson on the Evolution of HIV

In writing the Missing Link, I put together an outline for a lesson on using HIV resistance to help students better understand evolution. I'm starting now to flesh out that outline and find resources that teachers can tap in using an inquiry-based approach to teaching evolution.

In developing an inquiry, I always have to keep in mind my purpose. Maybe it's just me, but I always have to fight the tendency to drift to related science or to get lost in the evidence, forgetting my overall goal. So, I kept the following in mind as I worked:
  • Lesson Purpose: Students examine evidence of the evolution of HIV in response to antiviral drugs as an example of evolution occurring in their lives right now
  • Focus Question: What does the theory of evolution say?

In understanding the evidence, you and your students will probably need a big-picture understanding of HIV's genetic sequence. This one that I found is from the HIV database mentioned below, and it was a rosetta stone for me in understanding the rest of the evidence.

The source of evidence I worked with while writing the Missing Link was the research article "Mutations in Retroviral Genes Associated with Drug Resistance." The article summarizes the actual research detailing the evidence of HIV evolution at the codon level, but it is pretty technical, especially for use by secondary students. The site on which the article is posted gives other potentially good sources of evidence and resources that can be tapped for helping students understand the summary of mutations in the article.

I'm interested in the HIV Drug Resistance Database housed at Stanford University, and I'm focusing now on the portion of the site giving summaries of drug resistance. There, you and your students will find a section giving "Antiretriviral drug summaries." This seems to be a productive source for giving your students access to a high-level understanding of the clear evidence for HIV's constant and rapid mutation when it encounters drug therapy. Each of the links under that section takes you to a table giving the key mutations associated with a specific class of drug, and students can clearly see below the table the list of scientific publications from which the tables are constructed.

In the process, I stumbled on some other possibilities:
  • The Geography Search Interface from HIV Databases Site gives a pretty amazing tool by which students can examine the evidence for geographical distribution of different strains of HIV worldwide. Great for visual and kinetic learners!
  • If you or your students need to brush up on understanding HIV's basic structure or life cycle, a simple Google Images search gives a lot of quality images. I searched "HIV structure" and then looked at the web addresses for a sense of which ones were coming from reputable science sources. (Ok, I'll admit. Sometimes I also went for the easy stuff.)
  • I just started playing with the TRIP database. I've been working at UAB's medical school for a couple of years now, and they are focusing students on evidence-based medicine (the science behind good practice). TRIP is a database of evidence-based medicine, and I got several good hits when I initially searched on HIV there. An interesting feature is that it give patient information leaflets, which might help students who are asking, "Why do we need to know this?"
My next step is to address how I would scaffold these resources differently for middle schoolers in a life science course and high schoolers in general biology. That may have to wait a couple of weeks, however. Next week looks pretty busy.

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