It is common knowledge that every child receives half their genes from their mother and the other half from their father, but, in May 2006, one baby received the mother's genes and the other received the father's genes resulting in Black and White twins Alicia and Jasmin Singerl. The twins' mother is of mixed-race Jamaican-English heritage, while the father is of white German heritage.
Scientists have derived that the probability of a couple, each of a different race, has a one in a million chance of giving birth to twins of "different colour". A woman of mixed nationality would contain a mixture of genes coding for both black and white skin in her eggs, likewise, a man of mixed race will have a combination of different genes in his sperms. When these eggs and sperm merge together, they will create a baby of mixed race. During meiosis, egg ells are produced in the mother and a random selection of genes will be allocated to each other. The set of chromosomes in each egg cell is unique.
Occasionally the egg or sperm may contain genes coding for one skin colour, if both the eggs contain all white genes, the baby will be white or if both the eggs contain all black genes, the baby will be black. In this case, the twins' mother had released two such eggs, one with predominantly dark pigmentation genes and one with predominantly fair genes. Subsequently, one of the father's sperm containing all white genes fused with a similar egg and a sperm coded for fair skin fused with the egg with predominantly dark pigmentation genes (Darker gene is the dominant trait in this situation) which resulted with two babies of dramatically different colours.
Research has shown that skin colour is expressed by seven different genes. First generation hybrids carry half of the variants of each race since the parents contribute exactly 50% of their genes. Thus, second generation hybrids will have a greater range of combination, hence, mixed race couples will have children who have a greater variation in phenotype.
Clinical geneticist Dr Stephen Withers said the likelihood of a mixed-race woman having eggs that were predominantly for one skin colour was rare enough, let alone producing two of them, resulting in twins.
Christine Louie
4205662
From the article "Black and White Twins born by one in a million chances", published online 22 October 2006. http://www.dailymail.co.uk/news/article-411953/Black-White-twins-born-million-chance.html
