Multiple eggs are released or there is more than one ovulation. Both (or more) eggs are fertilized and you have fraternal twins. This can happen with or without fertility drugs.
Identical twins born with their bodies joined at some point and having varying degrees of http://www.answers.com/topic/residual duplication, a result of the incomplete division of the...
Chang and Eng Bunker ( as I recall, no relation to Archie) were the first pair to survive to adulthood and they hailed from Siam. (they were male) hence the name. It is a congenital anomality and is...