[London, September 9. Image via Getty]

LONDON, ENGLAND - SEPTEMBER 09: A Bonhams gallery assistant holds an engraved whales' tooth depicting Charles Darwin's 1834 voyage on HMS Beagle which is expected to fetch up to 50,000 GBP at auction on September 9, 2009 in London, England. The lot features in Bonhams' 'Travel and Exploration Sale' of items from 300 years of global expeditions. (Photo by Oli Scarff/Getty Images)