Science of Discworld III

his grandfather’s views must have influenced him, but probably only by affirming the possibility of species change. 3 The big difference was that from the very beginning, Charles was looking for a mechanism. He didn’t want to point out that species could change – he wanted to know how they changed. And it is this that distinguishes him from nearly all of the competition.
    The most serious competitor we have mentioned already: Wallace. Darwin acknowledges their joint discovery in the second paragraph of the introduction to Origin . But Darwin wrote an influential and controversial book, whereas Wallace wrote one short paper in a technical journal. Darwin took the theory much further, assembled much more evidence, and paid more attention to possible objections.
    He prefaced Origin with ‘An Historical Sketch’ of views of the origin of species, and in particular their mutability. A footnote mentions a remarkable statement in Aristode, who asked why the various partsof the body fit together, so that, for example, the upper and lower teeth meet tidily, instead of grinding against each other. The ancient Greek philosopher anticipated natural selection:
    Wheresoever, therefore, all things together (that is all the parts of one whole) happened like as if they were made for the sake of something, these were preserved, having been appropriately constituted by an internal spontaneity; and whatsoever things were not thus constituted, perished, and still perish.
    In other words: if by chance, or some unspecified process the components carried out some useful function, they would appear in later generations, but if they didn’t, the creature that possessed them would not survive.
    Aristotle would have made short shrift of Paley.
    Next, Darwin tackles Lamarck, whose views date from 1801. Lamarck contended that species could descend from other species, mostly because close study shows endless tiny graduations and varieties within a species, so the boundaries between distinct species is much fuzzier than we usually think. But Darwin notes two flaws. One is the belief that acquired characteristics can be inherited – Darwin cites the giraffe’s long neck as an example. The other is that Lamarck believed in ‘progress’ – a one-way ascent to higher and higher forms of organisation.
    A long series of minor figures follows. Among them is one noteworthy but obscure fellow, Patrick Matthew. In 1831, he published a book about naval timber, in which the principle of natural selection was stated in an appendix. Naturalists failed to read the book, until Matthew drew attention to his anticipation of Darwin’s central idea in the Gardener’s Chronicle in 1860.
    Now Darwin introduces a better-known forerunner, the Vestiges of the Natural History of Creation . This book was published anonymously in 1844 by Robert Chambers; it is clear that he was also itsauthor. The medical schools of Edinburgh were awash with the realisation that entirely different animals have remarkably similar anatomies, suggesting a common origin and therefore the mutability of species. For example, the same basic arrangement of bones occurs in the human hand, the paw of a dog, the wing of a bird, and the fin of a whale. If each were a separate creation, God must have been running out of ideas.
    Chambers was a socialite – he played golf – and he decided to make the scientific vision of life on Earth available to the common man. A born journalist, Chambers outlined not just the history of life, but that of the entire cosmos. And he filled the book with sly digs at ‘those dogs of the clergy’. The book was an overnight sensation, and each successive edition slowly removed various blunders that had made the first edition easy to attack on scientific grounds. The vilified clergy thanked their God that the author had not begun with one of the later editions.
    Darwin, who respected the Church, had to refer to Vestiges , but he also had to distance himself from it. In any case, he found it woefully incomplete. In his ‘Historical Sketch’, Darwin quoted from the tenth ‘and much improved’ edition, objecting that the anonymous author of Vestiges cannot account for the way organisms are adapted to their environments or lifestyles. He takes up the same point in his introduction, suggesting that the anonymous author would presumably say that:
    After a certain number of unknown generations, some bird had given birth to a woodpecker, and some plant to the