A pair of identical twins got mistaken for mother and daughter by a stranger, all because of one tiny difference in their appearance. It’s not always easy to tell siblings apart or know who’s the ...

Metastable epialleles may sound like complex science, but they help explain why identical animals can still look and act differently. For years, scientists asked why two mice with identical DNA could ...

Discovered: The world's lightest material; babies understand more than we thought; even in the womb, identical twins aren't completely identical; superweeds are resistant to RoundUp. Germans break the ...

Brooke and Brittany Davenport are not just twins, but the sisters are best friends on and off the volleyball court.

Ashley Ness' babies entered the world as quadruplets, but one of her babies never made it home from the hospital. Three years ...