The Island of the Colorblind

In hindsight, John feels, it is far from clear whether these few non-Chamorro immigrants had true lytico-bodig or classic ALS or parkinsonism. But some of their offspring, half Chamorro, have gone on to develop lytico-bodig. And though Kurland could not pursue the genetic hypothesis with the technology of the 1950s, he and his colleague W.C. Wiederholt are now looking at the children of the Californian Chamorros, to see if lytico-bodig appears in any of them.

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Kuru, a fatal neurological disease which had been endemic in the area for a century or more, could be transmitted, Gajdusek found, by the ritual practice of eating the brains of the dead. The disease agent was a newly discovered form of virus, a so-called slow virus which could remain latent in the tissues for years before giving rise to actual symptoms. The elucidation of kuru might not have been accomplished, one feels, had Gajdusek not combined a very sharp and sophisticated medical curiosity with a deep and sympathetic knowledge of the cultural beliefs and traditions of the indigenous tribes in the region. Such a combination of medical, biological, and ethological passions has underlain almost all of his work and has driven him to investigate geographical isolates throughout the world – not only the kuru and lytico-bodig in New Guinea, but the endemic goitrous cretinism, the cysticercosis with epidemic epilepsy, and the pseudohermaphroditism there; the muscular dystrophy in New Britain; the congenital orthopedic deformities in the New Hebrides; the Viliuisk encephalitis in Siberia; the hemorrhagic fever with renal syndrome in Korea; the genetic diseases of Australian aborigines; and dozens of others (during his 1972 expedition on the research vessel Alpha Helix, he paid a brief visit to Pingelap). Besides his hundreds of technical articles, Gajdusek has kept immensely detailed journals for the last forty years, which combine the hard science of his investigations with vivid evocations of places and people, and form a unique record of the life-work of one of the most extraordinary physician-naturalists of our time.

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A very full discussion of the ecological disaster in Guam has recently been provided by David Quammen in his book The Song of the Dodo: Island Biogeography in an Age of Extinction. He describes how the native bird populations, which had been numerous and varied in 1960, were brought to the verge of extinction little more than twenty years later. No one at the time had any idea what was causing this:

Where had the birds gone? What was killing them? Had they been devastated by an exotic disease, as in Hawaii? Had they been poisoned by cumulative doses of DDT? Had they been eaten by feral cats and tree-climbing pigs and Japanese soldiers who refused to surrender?

It was only in 1986 that Guam’s ‘ecological murder mystery’ was solved and the bird-eating tree snake, Boiga irregularis, was proved to be the culprit. There had been a spreading explosion of these snakes, starting in the southern savannahs in the 1950s, reaching the northern forests by 1980, correlating precisely with the wave of bird extinctions. It was estimated in the mid-eighties that there were now thirteen thousand snakes to the square mile, three million on the whole island. Having consumed all the birds by this time, the snakes turned to other prey – skinks, geckos, other lizards, and even small mammals – and these too have shown catastrophic declines. Going with this there has been a vast increase in the numbers of orb-weaving spiders (I saw their intricate webs everywhere), probably due to the decline of the lizards. Thus the inauguration of what ecologists call a trophic cascade, the accelerating imbalance of a previously balanced ecosystem.

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Lynn Raulerson had told me of something even rarer, an immense tassel fern, Lycopodium phlegmaria, which used to be common in the forest, but had now almost vanished, because most specimens had been poached for cultivation as house plants. Both this and the great ribbon fern are also to be found in Australia, and Chamberlain, while cycad hunting there, was fascinated by these and wrote of them in his 1919 book The Living Cycads: