In this episode, Stanford's David Relman talks about the microbial life that lives on and in humans. Princeton's Andrew Dobson discusses the importance of parasites to an ecosystem. And former National Science Foundation director Rita Colwell mentions a low-tech practice with big public health implications. All from a conference on microbes and the environment at the American Museum of Natural History. Plus we'll test your knowledge of some recent science in the news. Websites mentioned on this episode include