Interesting article by Elizabeth Kolbert in this week's New Yorker: "The Sixth Extinction?". In it, she examines the causes of the five previous "great extinction" events, and proposes we may be at the beginning of a sixth. Except in this case, the cause might be a little closer to home.
Humans now occupy every continent on the planet. We may be the most "successful" large organism in history. We are certainly adaptable and our intelligence has enabled us to dominate our environment like no other species.
Through such "innovations" as industrialized agriculture and high-speed transporation, pathogens can be distributed across the globe in days, rather than millenia. Are we our own worst enemy? Elizabeth doesn't mention it in her article, but I'm deeply concerned about the potential impact of monoculture in farming. Not only are we all consuming vast quantities of a single foodstuff (corn), but thanks to Monsanto, it's all one strain. A single virus could have a devastating impact on the food supply of the entire planet.