Jon_Herron's blog

Despite 25 years of intensive research, there is much the experts still don't know about HIV. Among the persistent mysteries is why, exactly, HIV infection causes AIDS. HIV infects and destroys helper T cells, which are needed to mobilize the immune system to fight pathogens. But HIV doesn't seem to kill enough helper T cells—at least not directly—to explain the immune system's eventual collapse. In recent years evidence has been accumulating in favor of a disease model in which the host's own immune response plays a key role in the cause of AIDS. Among this evidence is an analysis of the rate of viral evolution within individual hosts.

In my last post, I wrote about virologists using directed evolution to produce viruses that fight cancer. Another nice example of evolution being harnessed for medical use was published earlier this year. Katherine Excoffon and colleagues are working to develop effective gene therapy for cystic fibrosis.

If we can control evolution well enough to turn wolves into poodles, why can't we use the same method to turn viruses into magic bullets for cancer? Virologists are trying to do just that.

As Eli Meir has discussed, one of the take-home messages of our research on teaching natural selection is that students can benefit from repeated instruction on a fundamental concept.

Erin Naegle recently turned me on to Stephen R. Burton and Christopher Dobson's Spork & Beans exercise, which appeared in the February 2009 issue of American Biology Teacher.