When someone has a set of twins, they expect them to look reasonably similar. When a biracial couple has children, they also expect that the dominant genes will likely take over. Genetics, however, don’t always follow the “rules”. These twin sisters are an incredible example of that. Meet the one-in-a-million biracial twins Marcia and Millie Briggs.
Marcia and Millie Briggs: The Biracial Twins
Marcia and Millie Briggs are fraternal twins in England born to biracial parents via IVF treatments. Their parents said that when they were first born, they looked nearly identical. At 10 months of age, however, their mother began noticing that their daughter’s complexions were changing. It was Millie whose complexion she noticed first – she just kept getting darker and darker. (1)
Now teenagers, Marcia and Millie often get mistaken for best friends rather than sisters. Marcia has pale skin, blue eyes, and blonde hair. Millie, on the other hand, is darker-skinned, a bit taller, and has brown eyes. Her hair is the same texture as Marcia’s, only hers is black. (2)
Many of us wonder if this is even possible. Postdoctoral research fellow at the Broad Institute in Cambridge, Massachusetts Alicia Martin explains that it is. Race and skin color aren’t necessarily as connected as we’d like to think they are. Martins also says that skin color is not a binary trait.
“It’s a quantitative trait,” she explained. “and everyone has some gradient on this spectrum.”
Dr. Nancy L Segal explains this further, stating that many different genes are responsible for our skin tone.
“It could be one child inherits certain genes from both parents and the other child inherits sets of genes from the other parent. And that explains the different skin tones,” she said. “It’s just like how ordinary fraternal twins can look completely different from each other. They just inherit different sets of genes-one child gets the lighter ones, the other’s darker.” (3)
The Race Issue
National Geographic featured the pair on the front cover of their issue on race in 2018. The theme of the issue was race and how it defines, divides, and unites us. Naturally, the twins make many of us rethink everything we know about race and what it means.