I say evolved, but a note of caution is required. Most small people live in remote and impoverished parts of the world. It is difficult to know just how tall they would be if fed a protein-and calorie-rich supermarket diet. No one believes that African pygmies would grow much taller if transported en masse to California, but we would do well to remember that the children of Mayan refugees who moved to Los Angeles in the 1970s gained an additional 5.5 centimetres (about two inches) over their relations who stayed in Guatemala.
It is even possible that the most recent, and probably the last, pygmy tribe to be discovered will prove not to be pygmies at all, but rather people with a severe and rather specific nutritional deficiency. In 1954 a Burmese soldier marching through the montane forests near the joint frontiers of Burma, India, Tibet and China came across a village of small people. He was not quite the first to do so. Before Burma’s independence, a series of British explorers – lean, lone Indian Army officers – had traversed back and forth across the region where the four great rivers of Asia, the Irrawaddy, Salween, Mekong and Yangtse, descend from the Tibetan Plateau. Their reports are scanty, but consistent. They record the existence of an ethnically distinct group of ‘dwarfs’ who seemed to have their centre in the upper reaches of the valley of the Taron, a remote tributary of the Irrawaddy. The dwarfs were variously called Darus, Nungs, Naingvaws, Hkunungs or Kiutzu. They were elusive and no one had studied them at any length, yet most accounts agreed that they were a cheerful and hardy, if notably dirty, people who tattooed their faces, lived in tree houses, and were often enslaved by the taller hill-tribes such as the Lisu. A Captain B.E.A. Pritchard measured some Nungs and found they had an average height of 158 centimetres (five feet two inches). He later drowned while trying to ford the Taron after the Nungs cut the bridge that spanned it.
In 1962 the Burmese government decided to find out more. A caravan of military men and physicians walked for two weeks across razor-backed ridges and rope-bridged ravines to the Taron Valley. Their study was published in one of the world’s most obscure journals, the Proceedings of the Burma Medical Research Society, but it is clear and comprehensive. The Burmese found ninety-six people living in two villages. Disappointingly, there were no tree houses and no tattoos, but the men had an average height of only 144 centimetres (four feet eight inches). This was as short as the shortest African pygmies. Yet these people, who called themselves Taron after the river on which they lived, were clearly of Tibeto-Burman stock, and spoke a Tibeto-Burman language. Subsistence farmers of a meagre sort, they lived in conditions of abject poverty and squalor. Three generations previously, the Taron said, they had crossed over from Yunnan; a landslide had blocked the pass through which they had come and they had been in Burma ever since.
Who were they? The Burmese weighed up the evidence and decided that the Taron were probably identical to the Nungs of earlier reports, and therefore a race of genetically short people. How many more of them there were, and their precise origins, were questions left unanswered. The hypothesis that they were true pygmies appeared to be supported by the fact that they lived in close proximity to taller people whose diets seemed no worse than theirs. Yet there were disquieting aspects to the Taron. Of the ninety-six living in the two villages, nineteen were mentally defective. This is a high proportion, even allowing for the fact that they were inbred (pedigrees showed many first-cousins marriages). Several had severe motor-neuron disorders and were unable to walk. And the Taron themselves claimed that when they had come from China they had been of normal size; only in Burma had they become small. That is all we know of the Taron, and we are not likely to know more soon – foreigners have not been allowed into Upper Burma for decades. But it is possible that the Taron are not so much pygmies, or even dwarfs, but rather simply cretins.
It is not a pretty word, but it is the correct one. Cretins are people who are afflicted from birth by a mix of neurological and growth disorders. Traditionally, they have been classified into two types: ‘neurological’ cretins who are mentally defective, have severe motor-neuron problems and tend to be deaf-mute; and ‘myxedematous’ cretins who have severely stunted growth, dry skin, an absence of eyelashes and eyebrows and a delay in sexual maturity. A peculiarly vicious form of myxedematous cretinism, in which growth and sexual development simply stop at about age nine, is found in the Northern Congo. These Congo cretins may be in their twenties and still show no sign of breasts or pubic hair, menstruation or ejaculation, and they never grow taller than 100 centimetres (three feet three inches). This is an extreme. The Taron may have a milder form of the same disease.
Cretinism is a global scourge. In 1810 Napoleon Bonaparte ordered a survey of the inhabitants of the Swiss canton of Valais; his scientists found four thousand cretins among the canton’s seventy thousand inhabitants. The location is telling. As the Taron Valley lies in the foothills of the Himalayas, so Valais lies at the base of the Alps. Swiss cretins have not been spotted since the 1940s, but a belt of cretinism still tracks most of the world’s other great mountain ranges: the Andes, the Atlas, the New Guinea highlands, the Himalayas. What these areas have in common is a lack of iodine in the soil. People and animals alike rely on their food for a ready supply of iodine, but in many parts of the world, especially at high altitude, glaciation and rainfall have leached most of the iodine out of the soil so that the very plants are deprived. Cretinism is caused by a diet that contains too little iodine. Globally, about one billion people are at risk of iodine deficiency; six million are cretins.
In the Gothic cathedral of Aosta, ten kilometres south-east of Mont Blanc, the choir stalls are decorated with portraits of cretins. They were carved to keep their fifteenth-century viewers mindful of the unpleasantness of Eternal Torment: a local version of the fabulous creatures and demonic creatures of misericords elsewhere. Many of the cretins have a curious feature: their necks are bulging and misshapen; one even has a bi-lobed sack of flesh hanging from his throat large enough to grasp with both hands. Just over a hundred years after Aosta Cathedral was built, Shakespeare would write in The Tempest: ‘When we were boys/Who would believe that there were mountaineers/Dew-lapp’d like bulls, whose throats had hanging at them/Wallets of flesh?’
The Aosta cretins and Shakespeare’s mountaineers were goitrous. Goitre is an external manifestation of an engorged thyroid, a butterfly-shaped organ located just above the clavicles. Like cretinism, it is a sure sign of iodine deficiency. When first discovered in 1611, the thyroid was thought to be a kind of support for the throat, a cosmetic device to make it more shapely. In fact it is a gland that makes and secretes a hormone called thyroxine. The thyroid needs iodine to make this hormone, and should iodine become scarce, the thyroid attempts to restore order by the rather drastic device of growing larger. The result is at first a swollen neck, then a bulging neck, and finally, in elderly people who have lacked iodine all their lives, an enormous bag of tissue that spreads from beneath the chin onto the chest, and that contains vast numbers of thyroid tissue nodules, some of which are multiplying, others of which are dying, yet others of which are altogether spent. In England this is called ‘Derbyshire neck’.