If the sperm of two or more men were metaphorically put in a blender and prepared for artificial insemination, isn’t it possible to have twins with two dads? Has there ever been a documented case? Further, what would those twins be called? The word “fraternal” implies that both babies would have the same parents.
In: 6
Fraternal twins can have diffrent dads. Here is an article about a case where it happened [https://www.businessinsider.com/twins-with-two-different-fathers-2015-5](https://www.businessinsider.com/twins-with-two-different-fathers-2015-5)
It can happen with in vitro fertilization too the clinic makes mistakes
[https://www.nbcnews.com/id/wbna9438648](https://www.nbcnews.com/id/wbna9438648)
It is called https://en.wikipedia.org/wiki/Superfecundation How common it is for humans is not known. It is quite common for other animals like dogs and cats. Humans have most of the time just a single child and most humans are quite monogamous so it is not that likely to occur. Cats and dogs have multiple offspring most, around 5 are most common. They are alos not monogamous so multiple fathers for fraternal twin are quite common.
Even if two twins have different fathers it will be quite hard to know in many situations. It has to be quite obvious like in the case with the In vitro fertilization above where the was a clear difference in skin color. It is no different than a non-twin or identical twin where the father might not be the one that thinks he is the father. There are studies that have the result that 1 in 25 fathers are not biological fathers even if they think they are. So there have to be fraternal twins that have a different fathers and no one will ever know.
The common word usage might not have a name for it because it is not common for humans. If you look at the name in science idential twins are called Monozygotic and Fraternal twins are Dizygotic. A zygote is a cell formed when two gametes are combined, A gamete is a sex cell so an egg or sperm for humans.
So the scientific name means from one fertilized egg or from two fertilized egg and does not contain any more information. For 3 or more it is called polyzygotic so many fertilized eggs.
Latest Answers