I've got to say- I got pretty excited about the lecture on immunology. It reminded me that I've been meaning to post what is, quite possibly, one of my favorite quotes of all time. Written by Claude Combes, a parasite ecologist, I think it really nicely wraps up the main idea behind the Red Queen hypothesis as it pertains to coevolution with pathogens:
"One might add that being genetically unvarying when one has a determined parasite for an adversary is like taking the same route home every day when threatened by terrorists."
I like it so much that I even have it on my facebook profile.