One of the first steps in research is to dig into existing work on the subject, which is known as a “literature review.” So if you’ve been itching to develop your own theory of evolution, we have some good news: All the books that Charles Darwin had with him on his famous trip to the Galapagos Islands are now online for your reading pleasure.

During the course of two years, researchers at the National University of Singapore compiled a list of the books Darwin had on the Beagle—books that informed his now famous research—then transcribed and digitized them (including the illustrations) to make them freely available. The collection amounts to 180 books, comprising 404 volumes, 195,000 pages, and 5,000 illustrations. Two-thirds of the material was in English; the rest was written in French, Spanish, German, Latin, and Greek. It included books on travel and voyages, natural history, geology, history, and literature, as well as atlases and nautical maps. He even took some “light” reading, such as John Milton’s Paradise Lost, and Historia del Proceso de la Reina de Inglaterra, the 19th-century Spanish equivalent of 50 Shades of Grey.

Hey, it was a five-year voyage and the ship’s crew was all male.

One interesting aside is that most of the books weren’t actually Darwin’s. They belonged to the captain of the ship, Captain FitzRoy, and the crew. Turns out Darwin only packed a few books of his own. (The illustration with this story shows his cabin, with bookcases on all the walls.)

Figuring out the contents of the library wasn’t easy. A catalog of the books existed but was lost and the books themselves were dispersed at the end of the five-year voyage. Some 1980s research provided researchers with a starting point of 132 volumes. They also had notes from some crew members, Darwin’s diaries of his Beagle voyage and a number of his books, which sometimes included annotations. Some entries in his diary were pretty cryptic, (like “Ellis horse story”) but researchers assumed if he made the reference, it must have come from one of the books. It’s not as if he could have Googled it, after all.

Why go to all this trouble? What’s the value of reading Darwin’s source material, some of which is now 400 years old and contains dubious theories such as the belief that earthquakes were caused by expanding gas from vast underground fires?

First, it’s interesting to see who inspired Darwin. Few ideas charge out of a scientific mind on their own like Athena bursting from the head of Zeus. As fellow scientist Isaac Newton is quoted as saying, “If I have seen further it is by standing on ye sholders of Giants.[sic]”

Second, the library offers invaluable insight into Darwin himself and his work. Dr. John van Wyhe, the researcher who led the work in digitizing the Beagle library, noted that it would have been helpful to him when he was transcribing Darwin’s Beagle notebooks, because Darwin didn’t make thorough references and his handwriting was terrible. Also, Darwin made references to books in his library all the time. For instance, he used Werner’s Colours—the 19th century equivalent to the Pantone Matching System Color Chart—as a standard way to describe the color of things like fish scales and bird eyes. Without that book, he might as well have said, “Green like that dress Mom used to wear on Sundays.”

This being academia, there’s already controversy around the digitization of the Beagle library. The Darwin Manuscripts Project, which had already been working on digitizing Darwin’s personal library, noted that it had its own theories about the Beagle library as well and had already published what it believed was the definitive list of Darwin’s Beagle library. And, surprise, the two lists didn’t agree! (There are also other sources of Darwin’s research and libraries, such as the Biodiversity Heritage Library. Turns out transcribing Darwin online is a Thing. Who knew?)

The news has also given the opportunity for some people—the kind who point out that evolution is “only a theory”—to criticize Darwin’s later work, noting, for example, that some books published after Darwin’s voyage don’t support Darwin’s research and therefore his theory can’t be true.

We’re not going to get into that argument, if only to demonstrate our own instinct for self-preservation.