A rare first edition of "Origin of Species" sold Tuesday at auction for 103,250 pounds ($172,000). London's Christie's auction house said it had languished for years on a toilet bookshelf.
The book had been expected to sell for 60,000 pounds ($99,000).
On the same day, British authorities said they're searching for a leather-bound notebook Charles Darwin used in developing his theory of natural selection.
English Heritage made the appeal on Tuesday — the 150th anniversary of the publication of Darwin's "On the Origin of Species." English Heritage says thieves stole the notes in the 1970s or 1980s.
Darwin used the journal on a 1835 visit to the Galapagos Islands. It contains handwritten notes later developed into Darwin's book, the basis for the modern understanding of evolution.
This year marked the 200th anniversary of Darwin's birth.