Parasites in the brain. Flu viruses in the human genome. Manmade species of e coli. Carl Zimmer, a science writer and lecturer who has lent his name to a species of tapeworm, isn't afraid to venture into the creepier, crawlier domains of science, as his Big Think interview proved.

The author of "Parasite Rex" also addressed a variety of non-microscopic topics, including the changing speed of human evolution and the varying speed of human thought. Known for featuring pictures of readers' science tattoos on his blog, The Loom, Zimmer even revealed whether he is hiding any geeky body art of his own.