Picture credits 9: Benjamin S Fischinger/Shutterstock; 15: Raul654/Wikimedia; 21: IndustryAndTravel/Shutterstock; 23: Eric Gevaert/Shutterstock; 25: Elnur/Shutterstock; 27: Ollyy/Shutterstock; 29: Zagorodnaya/Shutterstock; 31: gopixa/Shutterstock; 33: Wellcome Images/Wikimedia; 37: MurzikNata/Shutterstock; 41: Panaiotidi/Shutterstock; 45: Arthimedes/Shutterstock; 47: Pleple2000/Wikimedia; 51: aodaodaodaod/Shutterstock; 57: Dreamy Girl/Shutterstock; 65: NOAA Photo Library; 67: Designua/Shutterstock; 69: Designua/Shutterstock; 71: BlueRingMedia/Shutterstock; 75: Peter Gardiner/Science Photo Library; 77: Designua/Shutterstock; 79: Science & Society Picture Library; 89: World History Archive/TopFoto; 91: Richard Wheeler, richardwheeler.net; 93: diepre/Shutterstock; 105: Capreola/Shutterstock; 115: lculig/Shutterstock; 119: TessarTheTegu/Shutterstock; 125: Designua/Shutterstock; 129: Designua/Shutterstock; 137: lotan/Shutterstock; 139: Ed Uthman, MD/Wikimedia; 145: AkeSak/Shutterstock; 147: eveleen/Shutterstock; 149: Birute Vijeikiene/Shutterstock; 151: Testudo/Wikimedia; 153: FamVeld/Shutterstock; 155: dr OX/Shutterstock; 157: s_bukley/Shutterstock; 161: MedievalRich/Wikimedia; 163: Spleines/Wikimedia; 165: Waraphan Rattanawong/Shutterstock; 167: krasky/Shutterstock; 169 t: metha1819/Shutterstock; c: Eric Isselee/Shutterstock; b: Susan Schmitz/Wikimedia; 171: Rudmer Zwerver/Shutterstock; 173: Istvan Csak/Shutterstock; 175: Dave Pusey/Shutterstock; 185: Maggy Meyer/Shutterstock; 187: Johan Swanepoel/Shutterstock; 189: GUDKOV ANDREY/Shutterstock; 191: Eric Isselee/Shutterstock; 193: JHVEPhoto/Shutterstock; 195: Olaf Leillinger/Wikimedia; 203: Federico Massa/Shutterstock; 207: Hein Nouwens/Shutterstock; 209: Mary Evans Picture Library; 213: Rama/Wikimedia; 215: aarrows/Shutterstock; 221: paula french/Shutterstock; 233: Volodymyr Goinyk/Shutterstock; 239 tl: dianewphoto/Shutterstock; tr: Galyna Andrushko/Shutterstock; bl: Tischenko Irina/Shutterstock; br: Nadezda Zavitaeva/Shutterstock; 247: seanbear/Shutterstock; 251: NOAA Photo Library; 253: Jim Peaco, National Park Service/Wikimedia; 255: irin-k/Shutterstock; 257: Jesse Nguyen/Shutterstock; 259: Rich Carey/Shutterstock; 266-7: Palenque/Shutterstock; 269: David Osborn/Shutterstock; 271: Sergei25/Shutterstock; 273: Nick Fox/Shutterstock; 275: LeonP/Shutterstock; 277: Victorian Traditions/Shutterstock; 281: Adrian Kaye/Shutterstock; 281: Katoosha/Shutterstock; 285: Chaikom/Shutterstock; 287: Brian Gratwicke/Wikimedia; 289: BMJ/Shutterstock; 291: Hindustan Times; 293: Andrey Bayda/Shutterstock; 297: Vadim Petrakov/Shutterstock; 299: Pressmaster/Shutterstock; 307: Didier Descouens/Wikimedia; 311: ESA/Rosetta/NAVCAM; 315: Richard Bizley/Science Photo Library; 319: Nicolas Primola/Shutterstock; 325: Lonely/Shutterstock; 327: InvictaHOG/Wikimedia; 329: Monkey Business Images/Shutterstock; 331: Markus Mainka/Shutterstock; 335: Denis Kuvaev/Shutterstock; 343: Designua/Shutterstock; 347: wong sze yuen/Shutterstock; 351: Alexey Losevich/Shutterstock; 353: wavebreakmedia/Shutterstock; 355: petarg/Shutterstock; 357: Hulton Archive; 359: Rido/Shutterstock; 361: Wichy/Shutterstock; 363: johnbraid/Shutterstock; 367: Anton Havelaar/Shutterstock; 369: Ross Stevenson/Shutterstock; 371: Ipatov/Shutterstock; 373: Bbski/Wikimedia; 377: oticki/Shutterstock; 379: designelements/Shutterstock; 381: Studio_G/Shutterstock; 383: Andrew M. Allport/Shutterstock; 387: Toni Barros/Wikimedia; 393: science photo/Shutterstock; 395: damerau/Shutterstock; 397: Pressmaster/Shutterstock; 399: GeK/Shutterstock; 403: Oksana Kuzmina/Shutterstock; 407: Laguna Design/Science Photo Library;
All other illustrations by Tim Brown