It's a blog! Mainly of book reviews.
The author suggests that Darwin was more concerned with geology than biology during the Beagle journey. From my recollections of The Voyage of the Beagle, both featured strongly in the published Journal, but in terms of theorising, geology hugely outweighs zoology or botany. Evolution is not mentioned in the contemporary writings about the voyage and only appears briefly in the Journal as a later interpolation.