We have all seen twins, some of us even have one! While whenever the word "twins" come to our mind, we think of fraternal or identical pairs. But did you know that there are many other types and ...

New reproductive technologies have yielded a vast array of novel variations on the two conventional twin types—identical and fraternal—as well as some curious twin-like sibships. When a Canadian ...

Elizabeth Williams, 3, peers at twin sister Alexa as her father, Marty, holds her while Joe Margotta swabs her cheek Wednesday afternoon as part of the King’s College twin study. Times Leader staff ...

New reproductive technologies have yielded a vast array of novel variations on the two conventional twin types—identical and fraternal—as well as some curious twin-like sibships. When a Canadian ...