Before Zombie Day comes to a close, I want to do a little braaaaaaaaaaain dump on where zombies actually fit into the scientific landscape (and to thank Joseph Hewitt for the amazing art he provided for all of us. As a huge Evil Dead fan, I especially appreciate my copy of the Necronomicon. Groovy.)
My colleague Lee Billings, with whom I have killed literally tens of thousands of zombies, and I started the day with a discussion of the connection between zombies and science, which took us to the roots of modern-day zombie-dom. It seems pretty clear that word and the basic concept comes from Vodun and then Haitian Voodoo. But these zombies are not scientific, they are expressly supernatural beings, corpses reanimated by sorcery.
The modern zombie, however, is a living creature that has been infected with a disease. This disease is often created by scientists, sometimes intentionally as a bioweapon. The modern conception of the zombie, then, has more in common with Mary Shelley's Frankenstein than it does with its voodoo forebears. Victor Frankenstein was the archetypal mad scientist. His creation has become a stand in for scientific hubris--sometimes literally, in the case of "frakenfoods."
Lee's objection to this was that all horror tropes have undergone similar transformations in recent years, if only to put a modern veneer on centuries-old stories. Vampires are just severely allergic to garlic now, and dragons breath fire through a biochemical reaction.
The difference between scientific zombies and vampires is that the zombies retain Frankenstein's pedigree as a cautionary tale. Even when vampirism is conceived of as a transmissible genetic mutation, it doesn't hold a candle to zombiism in terms of disease metaphors. In plenty of vampire stories, becoming a vampire isn't a fate worse than death. It's often desirable; you get better clothes, better sex, superpowers, and immortality. There are parallels with the demedicalization of homosexuality; vampirism as just another way of living (or unliving) rather than a diseased state.
Conversely, becoming a zombie is definitely bad. It is the definition of an epidemic (we should have had the book club team weigh in here), one that could quickly spell the end of humanity. This is why "zombie apocalypse" is now the predominant manifestation of the genre. Zombies end civilizations, whereas vampires are generally portrayed as being super-civilized, sometimes treating humans as we treat food animals.
Shelly's Modern Prometheus stole fire from the gods once again, and once again incurred their wrath. This apocalyptic reactionary theme is a recurring one. With scientific advances constantly ending the world as people knew it, the impression that those advances might end it period is not entirely unsurprising. So it is with genetically modified crops, nanotechnology, the LHC, or our own brand of synthetic life.