Mixed race people are Britain’s fastest growing ethnic group. Currently making up less than 2% of the population, they seem to be having an impact way beyond their numbers. Lewis Hamilton, Leona Lewis, Alesha Dixon and Theo Walcott are highly visible in the worlds of sport and entertainment. In America, there’s Halle Berry, Tiger Woods and now Barack Obama; all very special people right at the top of their chosen professions. And yet, it is only recently that mixed relationships have become more socially acceptable in this country, while right-wing groups continue to espouse that the mixing of races is destructive and against some kind of natural order.
Aarathi Prasad, a geneticist and mother of a mixed race child, sets out to challenge the science of racial purity and examines provocative claims that there are, in fact, biological advantages to being mixed race. It’s a controversial subject that has aroused much opposition from both ends of the political spectrum, but does greater genetic diversity confer advantages in humans, as seen in the breeding of plants and animals, or are lifestyle and environment the primary influences?
In plants and animals, when two very genetically different parents mate, their offspring can be much larger, fitter, and more robust than either of them. This is called hybrid vigour. Every animal inherits one copy of each gene from its parents. If those genes are the same they are homozygous, but if they are different the offspring will be heterozygous for that gene. Aarathi asks if hybrid vigour and heterozygosity apply to humans?
She meets Professor Bill Amos from Cambridge University’s Zoology department. He’s a world expert on the fitness of marine mammals. As well as finding benefits of genetic diversity in seals, he’s been finding it in humans too. “We are starting to find more and more evidence that whatever the disease, heterozygosity is beneficial in resisting infection… It strikes me as a very small step to say in terms of mixed race populations, mixed race individuals, I would certainly expect those individuals to have higher tolerance to disease, will be better at fighting disease than for example people who come from a more isolated population.”
Her research leads her to question why European populations seem to be subject to many more diseases such as dementia, skin cancer and multiple sclerosis than other populations. After all, as Europe is such a large continent one can expect a wide gene pool.
Population geneticist Dr Jim Wilson explains, “We can actually see that lots of people who wouldn’t normally consider themselves inbred…urban Europeans for instance…are actually rather inbred because they share a lot of ancestors.
It wasn’t all that long ago that there were only a million people living in Europe. So you only have to go back 20 or 30 or perhaps 40 generations and everyone in Europe is related and everyone in Europe’s parents are therefore related which means everyone in Europe is inbred, not inbred in the sense that the offspring of first cousins is inbred but inbred nevertheless – there is a continuum and we all lie on that continuum.”
This theory would counter those claims of the superiority of racial purity. Jim Wilson continues: “This idea of purity, it comes from a fallacy of superiority of the north European people. When in fact if we looked at this biologically, it’s much, much better not to be pure bred and you would rather be mixed so that you decreased the chances of recessive genes having an effect.”
Monday 2nd November 8PM – Channel 4