Non-identical twins are known to be physically different from each other, unlike identical twins who have the same physical characteristics. This has been further highlighted in the case of two non-identical twins who are of different skin colour: one of them inherited genes for white skin while her sister has genes coding for black skin colour.
Lucy and Maria Aylmer, the non-identical twins who are markedly different
Black & white pair of twins
The two non-identical twins from Gloucester, UK, Lucy and Maria Aylmer, have been in the spotlight for a while now. Reason: they are unusually not identical. From their appearances, it is clear that Lucy inherited the genes coding for white skin while Maria received those coding for black skin. They were born to a Caucasian father and a half-Jamaican mother 18 years ago; the latter is carrying genes for both black and white skin.
The biology behind non-identical twins
Non-identical twins are formed when two of the mother’s eggs that are released are fertilised by two different sperms. Instead of having only one egg ready to be fertilised, the ovary releases two eggs. Both are fertilised separately, such that two genetically different zygotes are produced. Non-identical twins will thus be pretty much like non-twin siblings, except that they shared the womb space at the same time.
The mother of the twins is of the British African Caribbean group, coming directly from Caucasian Brits. Their chances of having offspring with white skin are increased.
27% of British African Caribbean men were shown to have white ancestry from their father’s side. 13 % of the DNA inherited by both men and women of the British African Caribbean were, in fact, not originated from Africa. Furthermore, about 98 % of these men and women could trace their direct maternal ancestry back to Africa, with the rest originating in Europe.