One of the notebooks contains Darwin's famous quote "I think" and the first-ever Tree-of-Life diagram drawn by Darwin in 1837, two decades ahead of the publication of the theory of evolution in ...

Two notebooks, one containing Darwin's original 1837 diagram of the Tree-of-Life, are believed to have been stolen in late 2000 or early 2001 from Cambridge University library.

Charles Darwin's "Tree of Life" sketch is seen on a page of "Notebook B," one of the trove of Darwin documents that had been stored in the Cambridge University library until it went missing in 2001.

The tree is situated over a small creek that drains from the cliff onto the beach. Spruce is a species that can grow to over 300-feet-tall but the Tree of Life is thick and squat.

In the beginning of the Bible, the tree of life represents what sets humans apart from divinity – but other texts use the symbol to depict mankind’s relationship with God.