The beauty of genetics. Meet Lucy and Maria Aylmer, two non-identical twins from Gloucester in the UK. Born to a Caucasian father and a half-Jamaican mother 18 years ago, the girls’ looks are a perfect example of how genetic material from both parents can end up being expressed in a child.
Unlike identical twins, where a single egg is fertilised by a single sperm before splitting into two identical halves, non-identical twins are formed when the mother released two eggs instead of one, and they’re fertilised by two separate sperm. So while identical twins will end up being the same sex, the same blood type, and have very similar looks – they’re technically clones of each other – non-identical twins will really only have the same likeness and genetic similarities as non-twin siblings.
What happened in the case of Lucy and Maria was that their mother is carrying the genes for both black and white skin, and Lucy ended up with the genes that encode white skin, and Maria, the genes that encode black skin. Interestingly, many British African Caribbean people, like Lucy and Maria’s mother, are directly descended from Caucasian Brits, as a study conducted as part of a BBC documentary back in 2003 found, and this increases their chances of conceiving a child with white skin.
The researchers found that 27 percent of British African Caribbean men had white ancestry somewhere in their paternal line, and around 13 percent of the DNA inherited by British African Caribbean men and women did not originate from Africa, David Derbyshire reported for The Telegraph at the time. “Around 98 percent of men and women could trace their direct maternal ancestry back to Africa,” said Derbyshire. “The remaining 2 percent had a ‘mother line’ that originated in Europe.” Via These two British girls are twin sisters