The Island of the Colorblind

One also sees convergent evolution in the animal kingdom, with the separate evolution of eyes, for example, in many different phyla – in jellyfish, in worms, in Crustacea and insects, in scallops, and in cuttlefish and other cephalopods, as well as in vertebrates. All of these eyes are quite different in structure, as they are different in origin, and yet, they are all dependent on the operation of the same basic genes. The study of these PAX eye-coding genes, and other genes like the homeo-box genes, which determine the morphogenesis of bodies and organs, is revealing, more radically and deeply than anyone could have suspected, the fundamental unity of all life. Richard Dawkins has recently provided an excellent discussion of the development of eyes, in particular, in his book Climbing Mount Improbable.

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Sir Robert Schomburg described his great excitement on finding Victoria regia:

It was on the first of January 1837, while contending with the difficulties which, in various forms, Nature interposed to bar our progress up the Berbice River, that we reached a spot where the river expanded, and formed a currentless basin. Something on the other side of this basin attracted my attention; I could not form an idea of what it might be; but, urging the crew to increase the speed of their paddling, we presently neared the object which had roused my curiosity – and lo! a vegetable wonder! All disasters were forgotten; I was a botanist, and I felt myself rewarded. There were gigantic leaves, five to six feet across, flat, with a deep rim, light green above and vivid crimson below, floating upon the water; while in keeping with this astonishing foliage, I beheld luxuriant flowers, each composed of numerous petals, which passed in alternate tints from pure white to rose and pink.

And in the Victoria regia tank, under its giant leaves, I was later to learn, resided a strange animal, a small medusa – Craspedacusta by name. This was found in 1880 and considered to be the first-ever freshwater jellyfish (though it was subsequently realized to be the medusoid form of a hydrozoan, Limnocodium ). For many years, Craspedacusta was found only in artificial environments – tanks in botanical gardens – but is has now been found in several lakes, including Lake Fena in Guam.

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A favorite book of mine, one of a delightful series (‘Britain in Pictures’) published during the Second World War, was British Botanists by John Gilmour. Gilmour gives a particularly vivid and moving portrait of Joseph Hooker as a grand botanical explorer and investigator, as the son of his renowned botanist father, William Jackson Hooker (who after his years teaching in Glasgow became the first director of Kew Gardens) – and above all, in his relationship with Darwin: