New in paperback. Hardcover was published in 2006. Why do women stabilize our societies? Why can we enjoy and understand Shakespeare? Why are fruitflies uniform? Why do omnivorous eating habits aid our survival? ... This book shows that the statement "weak links stabilize complex systems" holds the answers to all these surprising questions, and many more. The author, a recipient of several distinguished science communication prizes, explains weak or low probability interactions, and uses them as connecting threads in a vast variety of networks from proteins to ecosystems.