How is black and white twins possible?

Black and white twins, often referred to as biracial twins, can occur when two eggs are fertilized by two sperm cells, resulting in fraternal twins with different skin tones. If the parents have different ethnic backgrounds, the twins can inherit varying combinations of genes responsible for skin color. This genetic variation can produce one twin with a darker complexion and the other with a lighter complexion, even though they are siblings. The phenomenon demonstrates the complex nature of genetics and inheritance.