A New Kind of Twin

Researchers in Australia have found the second-ever documented case of semi-identical twins, who share all the DNA from their mother but have different sets of genes from their father. A potential mechanism for such an uncommon occurrence is the fertilization of a single egg by two sperm cells. However, this scenario typically results in an inviable pregnancy, raising the question of what specific conditions allowed for the proper development of these twins. Continue reading A New Kind of Twin