1996 - The Island of the Colorblind

by Oliver Sacks

  (A variety of insects can pollinate cycads, mostly beetles and weevils, though one species of Cycas is pollinated by a bee – giving the possibility, one likes to think, of a delicious cycad honey.)

  90 One cannot think of these beautiful adaptations without feeling how excellent cycads are, in their own way, and how meaningless it is to see them as ‘primitive’ or ‘lower’ plants, inferior in the scale of life to ‘higher’ flowering plants. We have this almost irresistible sense of a steady evolutionary advance or progress (culminating, of course, in nature’s ‘highest’ product – ourselves), but there is no evidence of any such tendency, any global progress or purpose, in nature itself. There is only, as Darwin himself insisted, adaptation to local conditions.

  No one has written of our illusions about progress in nature with more wit and learning than Stephen Jay Gould, especially in his recent book, Full House: The Spread of Excellence from Plato to Darwin. They lead us, he writes, to a false iconography of the world, so that we see the Age of Ferns succeeded by the Age of Gymnosperms, succeeded by the present Age of Flowering Plants, as if the earlier forms of life had ceased to exist. But while many early species have been replaced, others continue to survive as highly successful, adaptable life forms, as with ferns and gymnosperms, which occupy every niche from rain forest to desert. If anything, we are really, Gould insists, in the Age of Bacteria – and have been for the last three billion years.

  One cannot look at a single lineage, whether of horses or hominids, and come to any conclusions about evolution or progress, as Gould shows. We must look at the total picture of life on earth, of every species, and then we will see that it is not progress which characterizes nature but rather infinite novelty and diversity, an infinity of different adaptations and forms, none to be seen as ‘higher’ or ‘lower.’

  91 Darwin was the first to argue that dispersal of seeds by sea water might be an important means of their distribution, and made experiments to explore their ability to float and survive salt water. Many seeds, he found, had first to dry but then might float for remarkably long periods: dried hazelnuts, for example, floated for ninety days and afterwards germinated when planted. Comparing these time periods with the rates of ocean currents, Darwin thought that thousand-mile ocean journeys might be common for many seeds, even if they had no special flotation layer (like cycad seeds). ‘Plants with large seeds or fruit,’ he concluded, ‘generally have restricted ranges, fand] could hardly be transported by any other means.’

  Driftwood, he noted, might sometimes serve as a transport across the seas, and perhaps icebergs too. He speculated that the Azores had been ‘partly stocked by ice-borne seeds’ during the glacial epoch. But there is one form of oceanic transport, Lynn Raulerson suggests, which Darwin did not consider (though he would have been fascinated had it come to his attention), and this is transport by rafts of pumice, blown into the ocean by volcanic eruptions. These may float for years, providing transport not only for large seeds but for plants and animals as well. A vast pumice raft, stretching across the horizon, with coconut palms and other vegetation, was reportedly seen off Kosrae three years after Krakatau blew.

  It is not enough, of course, for seeds to arrive; they must find conditions hospitable for colonization. ‘How small would be the chance of a seed falling on favourable soil and coming to maturity!’ Darwin exclaimed. The Northern Marianas – Pagan, Agrihan, Alamagan, Anata-han, Asuncion, Maug and Uracas – are doubtless visited by cycad seeds, but are too unstable, too actively volcanic, to allow them to survive and establish a viable colony.

  92 The history and naming of the oceanic cycads is a story at once picturesque and confused. Surely Pigafetta, sailing with Magellan, must have observed the cycads of Guam and Rota, but if he did, his descriptions are too vague for us to be certain. It needed a botanical or taxonomic eye to demarcate cycads in the first place, from the circumambient palms around them. It was not until the next century that such botanical skills appeared, and then they appeared, with a sort of synchronicity, in two men, Rheede and Rumphius, whose lives and interests ran parallel in many ways. Both were officers of the Dutch East Indies Company. It was Rumphius who first described a cycad, on the Malabar coast in 1658. It was Rheede, his younger contemporary, who was to become governor of Malabar and publish a Hortus Indicus Mal-abaricus in the 1680s (after Rumphius’ own manuscript for a Hortus Malabaricus was destroyed in a fire). Rumphius’ and Rheede’s cycads were taken to be the same, and both were called Cycas circinalis by Linnaeus. When the French botanist Louis du Petit-Thouars identified a cycad on the east coast of Africa in 1804, it was natural that he should call this C. circinalis too, though it would be recognized as a distinct species and renamed C. thouarsii a quarter of a century later.

  In the past few years there has been an effort to reexamine the taxonomy of the Pacific cycads, a task made peculiarly complicated, as Ken Hill notes, by ‘the successive recolonization of areas by genetically distinct forms…facilitated by aquatic dispersal of the buoyant seeds.’

  Most botanists now are disposed to confine the name C. circinalis to the tall Indian cycad (that originally figured in Rheede’s Hortus ), which grows inland and lacks buoyant seeds. This at least is Hill’s formulation; he sees the Western Pacific cycads as belonging to the C. rumphii complex, and the Marianas cycad, which he has named C. micronesica, as a unique species within this complex. David de Laubenfels, a cycad taxonomist at Syracuse, agrees that C. circinalis occurs only in India and Sri Lanka, but feels that Guam cycad belongs to an earlier-named species, C. celebica. Since, however, the Guam cycad has been called C. circinalis for two centuries, the likelihood is that it will continue to be called this, and that only botanists will insist on using its ‘correct’ name.

  93 Aboriginal forests, cycad forests, seem to excite feelings of awe and reverence, religious or mystical feelings, in every culture. Bruce Chatwin writes of Cycad Valley, in Australia, as ‘a place of immense importance’ on some aboriginal songlines and a sacred place to which some aboriginals make their final pilgrimage before death. Such a scene, of final meetings and dyings beneath the cycads (‘like magnified treeferns’), forms the ending of The Songlines.

  94 The term ‘deep time’ was originated by John McPhee, and in Basin and Range he writes of how those most constantly concerned with deep time – geologists – may assimilate a sense of this into their inmost intellectual and emotional being. He quotes one geologist as saying, ‘You begin tuning your mind to a time scale that is the planet’s time scale. For me, it is almost unconscious now and is a kind of companionship with the earth.’

  But even for those of us who are not professional geologists or paleontologists, seeing ferns, ginkgos, cycads, forms of life whose basic patterns have been conserved for eons, must also alter one’s inmost feelings, one’s unconscious, and produce a transformed and transcendent perspective.

  Journals

  Ahlskog, J.E.; S.C. Waring; L.T. Kurland; R.C. Petersen; T.P. Moyer; W. S. Harmsen; D.M. Maraganore; P.C. O’Brien; C. Esteban-Santillan; and V. Bush. ‘Guamanian neurodegenerative disease: Investigation of the calcium metabolism⁄heavy metal hypothesis.’ Neurology 45: 1340-44 (July 1995).

  Anderson, F.H.; E.P. Richardson, Jr.; H. Okazaki; and J.A. Brody. ‘Neurofibrillary degeneration on Guam: Frequency in Chamorros and non Chamorros with no known neurological disease.’ Brain 102: 65-77(1979).

  Bailey-Wilson, Joan E.; Chris C. Plato; Robert C. Elston; and Ralph M. Garruto. ‘Potential role of an additive genetic component in the cause of amyotrophic lateral sclerosis and parkinsonism-dementia in the Western Pacific.’ American Journal of Medical Genetics 45: 68-76 (1993).

  Bell, E.A.; A. Vega; and P.B. Nunn. ‘A neurotoxic amino acid in seeds of Cycas circinalis.’ In M.G. Whiting, ed., Toxicity of Cycads: Implications for Neurodegenerative Diseases and Cancer. Transcripts of Four Cycad Conferences. New York: Third World Medical Research Foundation, 1988.

  Brody, Jacob A.; Irene Hussels; Edward Brink; and Jo
se Torres. ‘Hereditary blindness among Pingelapese people of eastern Caroline Islands.’ Lancet 1253-57 (June 1970).

  Carr, Ronald E.; Newton E. Morton; and Irwin M. Siegel. ‘Achromatopsia in Pingelap islanders.’ American Journal of Ophthalmology 72, N°4: 746-56 (October 1971).

  Chen, Leung. ‘Neurofibrillary change on Guam.’ Archives of Neurology 38: 16-18 (January 1981).

  Cody, Martin, and Jacob Overton. ‘Short-term evolution of reduced dispersal in island plant populations.’ Journal of Ecology 84: 53-62 (1996).

  Cox, Terry A.; James V McDarby; Lawrence Lavine; John Steele; and Donald B. Calne. ‘A retinopathy on Guam with high prevalence in lytico-bodig.’ Ophthalmology 96, N°12: 1731-35 (December 1989).

  Crapper McLachan, D.; C. McLachlan; B. Krishnan; S. Krishnan; A. Dalton; and J. Steele. ‘Aluminum and calcium in Guam, Palau and Jamaica: implications for amyotrophic lateral sclerosis and parkinson-ism-dementia syndromes on Guam.’ Environmental Geochemistry and Health 11, N°2: 45-53 (1989).

  Cuzner, A.T. ‘Arrowroot, cassava and koonti.’ Journal of the American Medical Assoc. 1:366-69(1889).

  de Laubenfels, D.J. ‘Cycadacees.’ In H. Humbert and J.-F. Leroy, eds., Flora de Madagascar et des Comores. Gymnosperms. Paris: Museum National d’Histoire Naturelle (1978).

  Diamond, Jared M. ‘Daisy gives an evolutionary answer.’ Nature 380: 103-O4 (March 1996).

  —‘The last people alive.’ Nature 370: 331-32 (August 1994).

  Duncan, Mark W; John C. Steele; Irwin J. Kopin; and Sanford P. Markey. ‘2-Amino-3-(methylamino)-propanoic acid (BMAA) in cycad flour: an unlikely cause of amyotrophic lateral sclerosis and parkin-sonism-dementia of Guam.’ Neurology 40: 767-72 (May 1990).

  Feigenbaum, Annette; Catherine Bergeron; Robert Richardson; John Wherrett; Brian Robinson; and Rosanna Weksberg. ‘Premature atherosclerosis with photomyoclonic epilepsy, deafness, diabetes mellitus, nephropathy, and neurodegenerative disorder in two brothers: A new syndrome?’ American Journal of Medical Genetics 49, 118-24 (1994).

  Futterman, Frances. Congenital Achromatopsia: A guide for professionals. Berkeley: Resources for Limited Vision, 1995.

  Gajdusek, D. Carleton. ‘Cycad toxicity not the cause of high-incidence amyotrophic lateral sclerosis⁄parkinsonism-dementia on Guam, Kii Peninsula of Japan, or in West New Guinea.’ In Arthur J. Hudson, ed., Amyotrophic Lateral Sclerosis: Concepts in Pathogenesis and Etiology, Toronto: University of Toronto Press, 1987.

  —‘Foci of motor neuron disease in high incidence in isolated populations of East Asia and the Western Pacific.’ In Lewis P. Rowland, ed., Human Motor Neuron Diseases, 363-93. New York: Raven Press, 1982.

  —‘Motor-neuron disease in natives of New Guinea.’ New England Journal of Medicine 268: 474-76 (1963).

  —‘Rediscovery of persistent high incidence amyotrophic lateral sclerosis⁄parkinsonism-dementia in West New Guinea (Irian Jaya, Indonesia).’ Sections of the 1993 Journal of D. Carleton Gajdusek, 489-544. Bethesda: National Institutes of Health, 1996.

  Gajdusek, D. Carlton, and Andres M. Salazar. ‘Amyotrophic lateral sclerosis and parkinsonian syndromes in high incidence among the Auyu and Jakai people of West New Guinea.’ Neurology 32, N°2: 107-26 (February 1982).

  Garruto, Ralph M. ‘Early environment, long latency and slow progression of late onset neurodegenerative disorders.’ In S.J. Ulijaszek and C.J. K. Henry, eds., Long Term Consequences of Early Environments. Cambridge: Cambridge University Press, in press.

  Garruto, Ralph M.; Richard Yanagihara; and D. Carleton Gajdusek. ‘Cycads and amyotrophic lateral sclerosis⁄parkinsonism dementia.’ Letter to the editor, Lancet, 1079 (November 1988).

  Geddes, Jennian K; Andrew J. Hughes; Andrew J. Lees; and Susan E. Daniel. ‘Pathological overlap in cases of parkinsonism associated with neurofibrillary tangles.’ Brain 116: 281-302 (1993).

  Gibbs, W Wayt. ‘Gaining on fat.’ Scientific American 8, 88-94 (August 1996).

  Hachinski, V C; J. Porchawka; and J.C. Steele. ‘Visual symptoms in the migraine syndrome.’ Neurology 23: 570-79 (1973).

  Haldane, J.B.S. ‘Suggestions as to quantitative measurement of rates of evolution.’ Evolutions-. 51-56 (March 1949).

  Hansen, Egil. ‘Clinical aspects of achromatopsia.’ In R.F. Hess, L.T. Sharpe, and K. Nordby, eds., Night Vision: Basic, Clinical and Applied Aspects. Cambridge: Cambridge University Press, 1990.

  Herrmann, Christian, Jr.; Mary Jane Aguilar; and Oliver W. Sacks. ‘Hereditary photomyoclonus associated with diabetes mellitus, deafness, nephropathy, and cerebral dysfunction.’ Neurology 14, N°3: 212-21 (1964).

  Higashi, K. ‘Unique inheritance of streptomycin-induced deafness.’ Clinical Genetics 35, N°6: 433-36 (1989).

  Hill, K.D. ‘The Cycas rumphii (Cycadaceae) in New Guinea and the Western Pacific.’ Australian Systematic Botany 7: 543-67 (1994).

  Hirano, Asao; Leonard T. Kurland; Robert S. Krooth; and Simmons Lessell. ‘Parkinsonism-dementia complex, and endemic disease of the island of Guam. I – clinical features.’ Brain 84: Part IV: 642-61 (1961).

  Hirano, Asao; Nathan Malamud; and Leonard T. Kurland. ‘Parkinsonism-dementia complex, an endemic disease on the island of Guam. II – pathological features.’ Brain 84: 662-79 (1961).

  Hubbuch, Chuck. ‘A queen sago by any other name.’ Garden News, Fairchild Tropical Garden, Miami, Florida (January 1996).

  Hudson, Arthur J., and George P.A. Rice. ‘Similarities of Guamanian ALS⁄PD to post-encephalitic parkinsonism⁄ALS: possible viral cause.’ The Canadian Journal of Neurological Sciences 17, N°4: 427-33 (November 1990).

  Hughes, Abbie. ‘Seeing cones in living eyes.’ Nature 380: 393-94 (4 April 1996).

  Hussels, I.E., and N.E. Morton. ‘Pingelap and Mokil atolls: achromatopsia.’ American Journal of Human Genetics 24: 304 – 07 (1972).

  Jacobs, Gerald H.; Maureen Neitz; Jess F. Degan; and Jay Neitz. ‘Trichromatic color vision in New World monkeys.’ Letter to the editor, Nature 385: 156-58 (July 1996).

  Johnson, Thomas C; Christopher A. Scholz; Michael R. Talbot; Kerry Kelts; R.D. Ricketts; Gideon Ngobi; Kristina Beuning; Immacculate Ssemmanda; and J.W. Gill. ‘Late Pleistocene desiccation of Lake Victoria and rapid evolution of cichlid fishes.’ Science 273: 1091-93 (23 August 1996).

  Kauffman, Stuart. ‘Evolving evolvability.’ Nature 382: 309-10 (25 July 1996).

  Kisby, Glen E.; Mike Ellison; and Peter S. Spencer. ‘Content of the neurotoxins cycasin and BMAA in cycad flour prepared by Guam Chamorros.’ Neurology 42, N°7: 1336-40 (1992).

  Kisby, Glen E.; Stephen M. Ross; Peter S. Spencer; Bruce G. Gold; Peter B. Nunn; and D.N. Roy. ‘Cycasin and BMAA: candidate neurotoxins for Western Pacific amyotrophic lateral sclerosis⁄parkinson-ism-dementia complex.’ Neurodegeneration 1: 73-82 (1992).

  Kurland, Leonard T ‘Geographic isolates: their role in neuroepidemi-ology.’ Advances in Neurology 19: 69-82 (1978).

  —‘Cycas circinalis as an etiologic risk factor in amyotrophic lateral sclerosis and other neurodegenerative diseases on Guam.’ In Dennis W Stevenson and Knut J. Norstog, eds., Proceedings of CTCAD 90, the Second International Conference on Cycad Biology, 29-36. Milton, Australia: Palm & Cycad Societies of Australia, Ltd., June, 1993.

  Lebot, Vincent, and Pierre Cabalion. ‘Les kavas de Vanuatu: Cultivars de Piper methysticum Forst.’ Trans. R.M. Benyon, R. Wane, and G. Kaboha. Noumea, New Caledonia: South Pacific Commission, 1988.

  McGeer, Patrick L.; Claudia Schwab; Edith G. McGeer; and John C. Steele. ‘The amyotrophic lateral sclerosis⁄parkinsonism-dementia complex of Guam: pathology and pedigrees.’ Canadian Journal of Neurological Sciences (in press).

  Miller, Donald T.; David R. Williams; G. Michael Morris; and Jun-zhong Liang. ‘Images of cone photoreceptors in the living human eye.’ Vision Research $6, N°8: 1067-79 (1996).

  Mollon, J.D. ‘Tho’ she kneel’d in that place where they grew…’: The uses and origins of primate colour vision.’ Journal of Experimental Biology 146: 21-38 (1989).

&
nbsp; Monmaney, Terence. ‘This obscure malady.’ The New Yorker: 85-113 (29 October 1990).

  Morton, N.E.; R. Lew; I.E. Hussels; and G.F. Little. ‘Pingelap and Mokil atolls: historical genetics.’ American Journal of Human Genetics 24, N°3: 277-89 (1972).

  Mulder, Donald W.; Leonard T Kurland; and Lorenzo L.G. Iriarte. ‘Neurologic diseases on the island of Guam.’ U.S. Armed Forces Medical Journal 5, N°12: 1724-39 (December 1954).

  Niklas, Karl. ‘How to build a tree.’ Natural History 2: 49-52 (1996).

  Nordby Knut. ‘Vision in a complete achromat: a personal account.’ In R. E Hess, L.T. Sharpe, and K. Nordby, eds., Night Vision: Basic, Clinical, and Applied Aspects. Cambridge: Cambridge University Press, 1990.

  Norstog, Knut. ‘Cycads and the origin of insect pollination.’ American Scientist 75: 270-79 (May-June 1987).

  Norstog, Knut; Priscilla K.S. Fawcett; and Andrew P. Vovides. ‘Beetle pollination of two species of Zamia: Evolutionary and ecological considerations.’ In B.S. Venkatachala, David L. Dilcher, and Hari K. Ma-heshwari, eds., Essays in Evolutionary Plant Biology. Lucknow: Birbal Sahni Institute of Paleobotany, 1992.

  Norstog, Knut; Dennis W. Stevenson; and Karl J. Niklas. ‘The role of beetles in the pollination of Zamia furfuracea L. fil. (Zamiaceae).’ Biotropica 18, N°4, 300-06 (1986).

  Norton, Scott A., and Patricia Ruze. ‘Kava dermopathy.’ Journal of the American Academy of Dermatology 31, N°1: 89-97 (July 1994).