Darren Naish has a typically wonderful post up about the evolution of giraffe necks, with the delightful snippet that until 1999 people thought they had fewer neck vertebrae than they do.
I can’t add to the biology, so allow me to make a few comments about the role of the giraffe in the history of biology.
In the middle ages, the giraffe was known to most Europeans only by travellers’ reports, and from classical times it was called the “cameleopard”, as it was thought to be a hybrid between a camel, which was a familiar enough animal, at least to the eastern Mediterranean Europeans, and the leopard, which was still in Europe at the beginning of the historical period.
In the nineteenth century, in 1826, a giraffe was offered to the French king, Charles X, by the Pasha of Egypt. It was the first live animal in Europe, and the naturalist Geoffroy Saint-Hilaire was sent to attend it on its path from Marseille to Paris, by the Museum histoire naturelle. Thousands of spectators lined the streets as it walked to Paris, and there began a fashion of all things giraffish, à la giraffe. Geoffroy, the last of the French evolutionists, himself became celebrated, and he and the giraffe died within months of each other, so closely were their respective fates entwined.
But Geoffroy’s predecessor, Lamarck, whose theory of evolution was the first that received any attention in the scientific literature, himself made the giraffe something of a celebrated cause. In his Philosophie zoologique in 1809, he had proposed the famous misunderstanding that the long neck was the result of generations of giraffes striving to reach the upper leaves as the lower ones were eaten away, and that this striving caused longer necks to be passed down to progeny, thus gradually accruing the extreme neck of today. This is why Lamarck’s view of heredity, which was widely shared at the time, has come to be known as “Lamarckism”.
In 1831, Charles Lyell devoted almost an entire volume of his Principles of Geology to Lamarck’s views, ironically making Lamarck known in the English speaking world even as he demolished him. The example Lyell chose to discuss at one point was Lamarck’s giraffe. And it passed on to subsequent lore that Lamarck’s view of evolution was all about organisms “willing” themselves to change. Lamarck himself used the French word besoin, meaning a “want” or “need” – changes were brought about by needs. Lyell used the equally ambiguous English word “want”, and hence the misconstrual. Lamarck most certainly did not have the idea that organisms could will their evolution.
A voyaging naturalist named Charles Darwin received that volume en route, and read it thoroughly (no TV on board!). Lyell’s discussion of Lamarck’s view of species as temporary slices through a temporal sequence of change influenced Darwin to think hard about species (which I will return to in the second post on Darwin and species), and as is well known, Darwin came up with the idea that chance variations would be selected for their ability to make organisms better adapted, thus changing the constitution of a species.
The irony is, as Darren points out, that the adaptive explanation of the giraffe’s neck has in recent years been overshadowed by a sexual rather than environment selection explanation – giraffe necks are, it was said, the result of male contests, and female necks followed along with selection for that trait. Now it appears that Darwin was right all along – long necks are feeding adaptations. Thus the circle is complete.