Mixed twins are fraternal or non-identical twins born to

multiracial The term multiracial people refers to people who are mixed with two or more races (human categorization), races and the term multi-ethnic people refers to people who are of more than one ethnicity, ethnicities. A variety of terms have been used ...

families which differ in skin color and other traits considered to be

racial Race is a categorization of humans based on shared physical or social qualities into groups generally viewed as distinct within a given society. The term came into common usage during the 16th century, when it was used to refer to groups of va ...

features. From a biological point of view, the differences in these fraternal or dizygotic twins from two biracial parents are not surprising. In

humans Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

, a relatively small number of

genes In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

are thought to be responsible for

human skin color Human skin color ranges from the Dark skin, darkest brown to the Light skin, lightest hues. Differences in Human skin, skin color among individuals is caused by variation in pigmentation, which is largely the result of genetics (inherited from o ...

. Different alleles or gene variants code for differences in the melanin found within the skin. Within some groups are high frequencies of dark skin alleles, while others have high frequencies of light skin alleles, for example. The parents of such twins, who are typically both of mixed race, have a combination of alleles for light and dark skin in their

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

. Each

sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

egg cell The egg cell or ovum (: ova) is the female Reproduction, reproductive cell, or gamete, in most anisogamous organisms (organisms that reproduce sexually with a larger, female gamete and a smaller, male one). The term is used when the female game ...

possesses a random selection of genes from its mother or father. While not the most probable event, a sperm or egg may randomly acquire, for example, mostly alleles that confer light skin coloration or mostly alleles that confer dark skin coloration. In such cases, fraternal twins can differ from each other quite dramatically in terms of skin color or other physical characteristics. Numerous sets of mixed twins have been born.Twins in Black and White
/ref> Much more rarely, mixed twins can arise as a result of heteropaternal superfecundation.

In popular culture

While mixed twins are not as common in popular culture as identical ones, there are exceptions. In the 1970s reboot of ''

Wonder Woman Wonder Woman is a superheroine who appears in American comic books published by DC Comics. The character first appeared in ''All Star Comics'' Introducing Wonder Woman, #8, published October 21, 1941, with her first feature in ''Sensation Comic ...

'', the white-skinned Diana has a black-skinned twin sister named

Nubia Nubia (, Nobiin language, Nobiin: , ) is a region along the Nile river encompassing the area between the confluence of the Blue Nile, Blue and White Nile, White Niles (in Khartoum in central Sudan), and the Cataracts of the Nile, first cataract ...

, who was kidnapped at birth by

Ares Ares (; , ''Árēs'' ) is the List of Greek deities, Greek god of war god, war and courage. He is one of the Twelve Olympians, and the son of Zeus and Hera. The Greeks were ambivalent towards him. He embodies the physical valor necessary for ...

and is historically

DC Comics DC Comics (originally DC Comics, Inc., and also known simply as DC) is an American comic book publisher owned by DC Entertainment, a subsidiary of Warner Bros. Discovery. DC is an initialism for "Detective Comics", an American comic book seri ...

' first black superheroine. Though Nubia's story has been retconned over the years since her first appearance, her original identity as Diana's fraternal twin sister was retold in the 2021 young adult graphic novel '' Nubia: Real One''. In the 2010 young adult novel ''The Other Half of My Heart'' by Sundee T. Frazier, the biracial King twin sisters-the white Minerva and the black Keira-deal with prejudice when their black maternal grandmother invites them to compete for the title of Miss Black Pearl Preteen of America.

References

Twin Multiracial affairs {{family-stub