The Marais book
When Locke leaves his Saharan hotel room, he picks up a book on the floor and takes it with him. Later in a Spanish hotel room, after the girl picks up the gun, the same book with an ape skull on the cover is seen on a table. However, when Rachel opens the suitcase of David's belongings that she collected from the embassy, that book is inside, back cover visible, and she picks it up for a second. It's as if he really didn't take the book and it stayed with the rest of his things. I have no explanation of how one object so prominently featured in the movie can seem to be in two places at once. Goof or clue?
The book happens to be "The Soul of the Ape" by Eugene Marais, a non-fiction, part scientific, part philosophical work about the advanced, human-like thought processes of Baboons. It was finally published in 1969, fifty years after it was written and 33 years after Marais' suicide. What does Peploe's DVD commentary say about this book?