Like a Virgin by Prasad, Aarathi (recommended reading txt) 📕

Written at a time when, in many places, miscegenation was outlawed and apartheid was actively enforced, the book raised several controversial issues surrounding the genetics of human offspring.

Haldane asked whether inequality among men was fundamental and genetic, if the sterilization of genetic ‘defectives’ was appropriate or wrong, and what could be expected if mixed race children were accepted (and more regularly born into the world). He looked at whether certain races and certain social classes might be endowed with innate superiority, or stand as a ‘pure’ race – a belief he attacked. He wrote that recent learning about human inheritance had ‘been used to support proposals for very drastic changes in the structure of society’ – a clear reference to the treatment of Jews in contemporary Germany. He continued: ‘And the stringent measures which have been taken... are said to be based on biological facts. I do not believe that our present knowledge of human heredity justifies such steps.’

After seventy-five years, the questions Haldane posed remain incendiary, and though our present knowledge of human heredity is growing exponentially each year, the sum total of accumulated data that has anything to do with race is minimal.

In 2008, two members of Parliament called for a ban on marriages between first cousins in the UK. In large part, their reasoning was based on data suggesting that Pakistani families from the West Midlands of England accounted for about thirty-three percent of the recessive genetic disorders in the region, but only around 4.1 percent of total live births, a dramatic statistic. The disorders were recorded, in the language of medicine, as ‘recessive metabolic errors’. These are mistakes that only affect a child if that child inherits a copy of the ‘bad’, mutated, disorder-creating gene from both of his or her parents. And this is more likely to happen among parents who are closely related – who are consanguineous, that is, ‘share blood’.

For several reasons, however, the statistics that the politicians used were skewed. There were problems with the way the data were gathered, and other studies over the years have shown that the risk of first cousins having a child with a recessive disease is quite low – no more than for the community overall. The issue wasn’t that first cousins were marrying, it was that everyone in this particular community was slightly more likely than the general population to carry the mutant gene.

When epidemiologists want to investigate the chances that a certain group may be prone to recessive errors, they look at genetic load, the overall number of harmful mutations the average person is carrying, rather than specific gene mutations. Unfortunately, genetic load is not always simple to translate into morbidity and mortality rates – the chance that a foetus will not make it to full term, or that a child will have difficulty surviving into adulthood, let alone inheriting a genetic disorder. The medical statistics, for example, do not indicate that rare recessive genes are more likely to cause miscarriage than other factors. Moreover, imagine that one of the shared grandparents of two married cousins carried a gene for albinism, which would give each of the cousins’ offspring a fifty percent chance of being albino. That doesn’t necessarily mean that this grandparent carried any other recessive mutant gene, or that the children will automatically be unhealthy or have any other disorder – the genetic load would be small, but the chance of being albino would be relatively high. Finally, consanguineous marriages tend to be more prevalent among people with lower socio-economic status, which coincides, in and of itself, with higher rates of morbidity and mortality, as shown in Sir Michael Marmot’s famous study of Whitehall bureaucrats. The politicians’ motion was based on an oversimplified view of heredity and epidemiology, to say the least.

Apart from the fact that the proposed law did not take into account all of this evidence, it would have turned a blind eye to risky reproductive behaviours that are currently accepted among many other groups. It is not questioned, for instance, that women nearing menopause should be able to procure fertility treatments, even though it is understood that older mothers are more likely to give birth to children with chromosomal abnormalities; nor that people with Huntington’s disease or other debilitating genetic disorders should retain the right to have children, despite an established fifty percent risk of the condition being inherited. Should a consenting adult be penalized for choosing a partner who might increase the risk of a genetic anomaly in his or her children? If so, would health services be required to screen potential reproductive partners, in the way that the charity Dor Yeshorim checks enrolled Orthodox Jewish families for a handful of recessive disorders before an arranged marriage goes forward? The law would have taken the choice of looking for a recessive trait out of the hands of the people having the child and put it in the hands of the government – a very drastic change in the structure of society. It would set a very disturbing precedent. Yet, the premise on which the law was proposed is quite basic: the premise that genetic variation is good and inbreeding is bad.

Inbreeding, of course, is what we normally call it when close relations mate. Between the closest of relations, we brand this incest, from the Latin for unchaste or impure. Genetically speaking, this labelling could not be further from the truth, however, because inbreeding limits the genes available to create any offspring, and so maintains a relatively pure familial gene pool; no truly foreign DNA is involved. As such, you could say that the ultimate form of inbreeding is making babies without a partner – that is, when reproduction does not involve sex at all.

The incest taboo is universal, though what it means for a particular community depends on