By Jonny Lupsha, Wondrium Staff Writer
Two of Charles Darwin’s handwritten notebooks vanished in 2001. They were returned to Cambridge University anonymously in a pink bag after a 20-year search. His first notes on natural selection were inside.

Librarians at Cambridge University breathed a huge sigh of relief on March 9 when they discovered the contents of a pink bag left in the public area of their library. It contained historical artifacts dating back to the 1830s: two of Charles Darwin’s original handwritten notebooks, which were also the first to detail his thoughts on evolution by natural selection. They were first found to be missing in 2001, but 20 years of searching bore no fruit, until an unknown person returned them to the Cambridge University library.
During the 1830s, Darwin’s life was steeped in new ideas and discoveries. In his video series What Darwin Didn’t Know: The Modern Science of Evolution, Dr. Scott Solomon, Associate Teaching Professor at Rice University, defines this pivotal point for Darwin and what it entailed.
Questioning Special Creation
In Charles Darwin’s time, it was believed that species were fixed entities that came into existence through “special creation.” However, a trip to the Galapagos Islands changed that belief for Darwin. He studied several species and got samples of them, including the now-famous finches that became a staple of his argument for evolution.
“He kept his thoughts private, writing in his personal notebook that ‘Such facts would undermine the stability of species,'” Dr. Solomon said. “All of these observations were leading to a big idea, but it wasn’t yet fully formulated. [Then] a key moment came back in England in September 1838, when he read An Essay on the Principle of Population, by economist Thomas Malthus.”
In Malthus’s essay, he noted that the rate of human population growth vastly outpaced the rate at which our food supply was growing. Malthus believed this would cause a crisis of a food supply shortage. Darwin saw the bigger picture.
“Darwin realized that limited resources and the struggle of individuals to survive could apply to any species,” Dr. Solomon said. “If so, that meant that the individuals with traits that make them better at competing for the limited resources would have a better chance of surviving and reproducing. This insight was critical because it provided a mechanism for how evolution could happen.”
The Best Things Come to Those Who Wait
After making this discovery, Darwin only shared his idea with his close friends. It took more than 20 years before he made his discoveries public. Why?
“The reasons for Darwin’s delay in publishing his theory of evolution have long been debated,” Dr. Solomon said. “Part of it may have been his theological training. Darwin had been very impressed by William Paley’s book, Natural Theology, which he read as a student at Cambridge.”
Paley’s famous analogy was that if a reasonable person found a watch lying on the ground and had never seen one before, they would conclude from its complexity that it must have been designed by some kind of watchmaker. Likewise, plants and animals are so complex and so naturally suited for their environments, Paley said the natural world must have been designed by a creator.
“Now, Darwin was moving beyond Paley’s argument, which he discussed with his pious future wife, Emma, who was concerned but also supported him,” Dr. Solomon said. “Darwin’s own emerging view was that life changes over generations, unlike a watch. Instead of a single, unchanging act of creation, all of nature seemed to change over time in ways that suggested, as he put it, that ‘everything in nature is the result of fixed laws.'”
And it all started in a handful of notebooks, two of which have finally returned home.