Dr Schubert took me around his garden, where he grew every kind of vegetable. 'If you treat the plants right, you can grow anything here,' he said, pointing to some out-of-place aubergines. 'It's a mystery to me why the first settlers had such problems. But you have to tend them constantly. If you leave them the jungle quickly overruns everything. It's the same with people. The Germans are caught in a trap. They know they cannot go back to a country they would never understand, but they are determined to maintain their cultural independence. They are inbred, and it is getting worse. You can already see the effects. I try to tell them. I say, 'Look at the way you breed animals,' and they nod and carry on as before. They can't help it.' Child mortality was increasing, he said, a number of the younger people had severe mental as well as physical problems, and there were clear patterns of hereditary disability. The pastor was now refusing to marry couples who were related, but the German families were now so biologically enmeshed you couldn't tell who was related to whom. It was most noticeable in the youngest children. A slack, bespittled jaw here, there a drooping eye. A few were obviously retarded, but most were just slow, the gears of heredity grinding, as cousin married cousin, as the handful of old, 'pure' German families lived off their dwindling genetic capital.
The text books are firm: 'Fairly recent isolation of a small section of a population with consequent inbreeding, such as can occur when a group emigrates to a country with different social and religious customs, will result in a higher incidence of recessive genetic disease than in the original parent population.' The fourteen peasant families who travelled on the steamer Uruguay held in their genetic makeup, as do all of us, a number of deleterious genes. 'Such genes are usually recessive. Under a system of random mating such as exists in most civilised countries, the accident of marriage sometimes brings such recessive genes together, which will then express themselves to some degree in the offspring issuing from such a union.' In the case of marriage between cousins, the likelihood of both partners being heterozygotes, carrying one copy of the recessive gene inherited from mutual grandparents, and thus of an accident occurring, is obviously far higher; first cousins carry one-eighth of their genes in common. With every generation that intermarries, the likelihood of a manifestation of deleterious genes grows.
Take albinism, the congenital lack of pigmentation which results in abnormally white skin and red eyes. Roughly speaking, one person in fifty is heterozygous for this condition (that is they carry, but do not manifest, the recessive gene associated with albinism); so the chances of marrying someone with a similar gene at random is 1/50 x 1/50 = 1/2500. The expectation among offspring is one in four, so the frequency of albinos in the population is 1/10,000. (Actually it is rather less frequent than that.) The mathematics for cousins is very different. If an individual marries a cousin, his chance of being heterozygous for albinism is 1/50, but the chance of her also being heterozygous is 1/8, thus 1/50 x 1/8 = 1/400, more than six times more likely. If an albino marries a cousin, there is a 1/4 chance that she carries the recessive gene for albinism, and that they will have equal numbers of albinos and children carrying the recessive gene. If two albinos have children and are related, they will have albino children. Among the San Blaz Indians of Peru, albinos are not permitted to marry.
Dr Schubert said there were no albinos in Nueva Germania, yet.
The idea of breeding human beings is an old one; Plato suggested the breeding of a race, by controlling human variability. Elisabeth and Bernhard Forster's attempt to create a pure-blooded German colony was unscientific in the extreme, but it carried at its centre the fiction of all racism-that racial traits can be characterised as 'better' and 'worse', and that the 'valuable' traits can be preserved by breeding. They could not know it, but preserving 'valued' traits could work only if they could have plotted the genetic inheritance of each individual, for otherwise how could they know which harmful traits were being bred along with the ones they valued?
In 1839 Charles Darwin, the 'father of evolution', married his first cousin, Emma Wedgwood-both were of impeccable intellectual and social pedigree. They had ten children: some of Darwin's children were people of marked scientific ability, and three were members of the Royal Society; but most were also sickly and delicate, three died as infants, and the last child, Charles Waring Darwin, was mentally deficient and died aged two without ever learning to walk or talk.
Was this the end of Elisabeth Nietzsche's pure Aryan colony, a tribe becoming more blonde and blue-eyed with every generation, but simultaneously degenerating? In the four or five generations since the first colonists had arrived, the families had so interbred that they had even begun to look the same; perhaps that was because so many of the founders had come from the same part of Germany, or was the effect of the environment and nutrition; one physical type, tall, with high cheekbones, blue eyes and fair hair, seemed gradually to be predominating, just as the Saxon accent brought by the majority of the original settlers had subsumed other local German dialects.
If you take two mice and breed them, and then inbreed their offspring, and then their offspring, within twenty generations you create clones, mice that are genetically identical, the same mouse. 'You can't explain it to the people here,' said Dr Schubert. 'It's partly that they don't understand, but also they don't want to understand. They need to preserve their separateness to maintain their pride; without that what would they have? But if they do not change their ways, who knows what will happen to them?' The identical mice at the twentieth generation are sterile mutants.