Marcia and Millie are 11 years old. They have different complexions: Marcia has fair skin and Millie has brown skin. And they’re fraternal twins. The Biggs sisters are on the cover of the National Geographic race issue. And their story might challenge your perspective on race.

The twins were born in 2006 in Birmingham, England. Their mother, Amanda, is English-born, and their father, Michael is of Jamaican descent. Marcia closely resembles her mother and Millie closely resembles her father. But complexions aside, they both share similar features with both of their parents.

Amanda says that from the start, people were curious about the black and white twins. Now that the girls are older, they get their fair share of questions, too. Overwhelmingly, most of the comments they hear from others aren’t judgmental, but shocked and curious. Still, the girls have a strong understanding of what racism is.

“Just because you’re a different color doesn’t mean that you have to change the way you are just to be like someone else,” Millie said. “People say, ‘Don’t judge a book by its cover.’ Don’t judge other people by their looks, because they could be so much different on the inside.”

Meet Marcia and Millie Biggs, the black and white twins on the cover of the National Geographic race issue.

The National Geographic race issue came to be when the magazine decided to acknowledge their past racist coverage.

Marcia and Millie Biggs are more than a photo opportunity. They’re smart girls with unique perspectives who can teach us a lot about the world. And by sharing their story — not just their pictures — National Geographic is taking a step in the right direction to challenge stereotypes and start conversations.