James and Daniel are twins. What sets them apart is that one is white and one is black – and the differences don't end there, as Joanna Moorhead discovers.
The two teenage boys sitting on the sofa opposite are different in almost every way. On the left is James: he's black, he's gay, he's gregarious, and he's academic. He's taking three A-levels next summer, and wants to go to university. Daniel, sitting beside him, is white. He's straight, he's shy, and he didn't enjoy school at all. He left after taking GCSEs, and hopes that his next move will be an apprenticeship in engineering.
So, given that they are diametrically opposed, there is one truly surprising thing about James and Daniel. They are twins.
They were born on 27 March 1993, the sons of Alyson and Errol Kelly, who live in south-east London. And from the start, it was obvious to everyone that they were the complete flipside of identical. "They were chalk and cheese, right from the word go," says Alyson. "It was hard to believe they were even brothers, let alone twins."
The boys' colour was the most obvious, and extraordinary, difference. "When James was born he was the spitting image of Errol, and I remember seeing his curly hair and thinking – he's just like his dad. It was another two hours before Daniel was born: and what a surprise he was! He was so white and wrinkly, with this curly blond hair."
It wasn't the first time nature had shocked Alyson and Errol. Daniel and James were the family's third set of twins: Errol and Alyson each already had a set with a previous partner. Errol's first set are fraternal boys, Shane and Luke, who are 21; Alyson's are identical boys, Charles and Jordan, 20. The only singleton in the house is the couple's youngest child, and only daughter, 14-year-old Katie. "Apart from her, it's twin city," says Alyson. "At least life was made a bit easier by the fact that we always had two of everything."
But it was clear that having one black and one white twin was going to mark the family out, wherever they went. "We'd go on holiday and people would say, 'Is that one a friend you brought along?'" says Alyson. For Errol the response of strangers was harder to deal with. "People didn't believe Daniel was mine," he says. "They didn't always say anything, but I could tell it was what they were thinking."
So how does it happen that a white and a black partner – who would usually produce, as Alyson and Errol did in their other children, black-skinned offspring – have a child who is as white as his mum? I spoke to Dr Jim Wilson, population geneticist at Edinburgh University – and his first question was, "What is Errol's heritage?" Errol is Jamaican – and that, says Jim, is the basic explanation.
"It wouldn't really be possible for a black African father and a white mother to have a white child, because the African would carry only black skin gene variants in his DNA, so wouldn't have any European DNA, with white skin variants, to pass on," he explains.
"But most Caribbean people, though black-skinned, have European DNA because in the days of slavery, many plantation owners raped female slaves, and so introduced European DNA into the black gene pool.
"The thing about skin colour is that even a bit of African DNA tends to make a person's skin colour black – so to be white, the child must have inherited more of the father's European DNA with its white skin variants. Added to the mother's European DNA, this led to a child with white skin – while his brother, who is black-skinned, inherited more of his father's African DNA.