Créditos de las imágenes

Los editores quieren agradecer a las siguientes personas y entidades su permiso para la reproducción de ilustraciones y fotografías:

Science Photo Library / The Bridgeman Art Library / Humboldt-Universität, Berlín / Alinari / Agnew’s, Londres, UK / Private Collection / Photo Scala Florencia / Heritage Images / The British Library, © 2010 / Alamy / The Print Collector / PhotosI2.com / ARJ / BPK, Berlin, © 2010 / Corbis / Bettmann / The Granger Collection, Nueva York / Charles Walker / Interfoto / The Granger Collection, Nueva York / Archives Charmet / Bibliothèque de la Faculté de Médecine, Paris; Mary Evans Picture Library / Lebrecht Music and Arts Photo Library / Getty Images / Hulton Archive / Wellcome Library, Londres / White Images, ©2010 / Royal College of Surgeons, Londres / HIP / Charles Walker / Science & Society Picture Library / Popper-foto / The Advertising Archive / Hulton-Deutsch Collection / 19.ª era 2 / HIP / Oxford Science Archive / National Library of Medicine, Bethesda, Maryland / Keystone / Ross Ressmeyer / North American AstroPhysical Observatory / TopFoto / Fortean / Blackmore / NASA / Continental Dynamics Workshop / NSF / Science Faction / Louie Psihoyos / Professor Alex Kacelnik / Behavioural Ecology Research Group / Oxford University / Fotopress / Ross Setford / Rex Features / Photo by Capital Press Agency / Barcroft Media / Barcroft India.