Yeah, Eng and Chang were born in Bangkok, hence the term Siamese twins.
Even monozygotic twins can look different, if something bad happens in utero. Sometimes, the twins still share a placenta and twin-to-twin transfusion syndrome occurs. TTTS is basically where one twin gets all the nourishment.
Dizygotic twins occasionally have the opposite: Chimera syndrome. Basically, a chimera is a pair of dizygotic twins who merge before attaching to the uterine wall. One man(?) in South Africa was like this and actually had working genitalia for both sexes.
Geneticists love twins. You can test any trait's hereditability by comparing twins. |