What are Fraternal Twins

What are Fraternal Twins

This article will give you more information on fraternal twins, and the difference between identical twins and fraternal twins.
Twin sisters
Twins, in simplest terms, are defined as two offspring born during the same pregnancy. Twins can be identical, i.e. with similar physical appearance, or non-identical or fraternal, i.e., with dissimilar physical appearance. Here we will see more on fraternal twins, and the difference between fraternal and identical twins.

An Overview on Fraternal Twins

Also known as dizygotic twins or non-identical twins, fraternal twins are born when two eggs are fertilized individually by two sperm cells. The two fertilized eggs form two different zygotes, which leads to the development of two non-identical twins. Two different placenta are formed, that sometimes fuse into one single one. As they are formed due to two different fertilization methods, there are rare chances of the twins having similar genetic or chromosomal structure. You may find some similarities between two fraternal twins, but, these are merely because the two are of the same age and born to same parents. In most of the cases, fraternal twins are starkly different from one other.

For better understanding, we can compare the development of fraternal twins with identical twins. In case of identical or monozygotic twins, only one single egg is fertilized by two different sperms which later is divided after fertilization. Therefore, identical twins have a same genetic or chromosomal structure and they look identical. It should be noted that identical twins, in most of the cases, are found in offspring of the same sex (twin boys or twin girls); whereas fraternal twins can be found in offspring of same as well as different sex.

Facts
  • They are more commonly found than identical twins.
  • Highest incidences are found in Africa with as many as 1 among 20 cases (In other parts of the world, 1 in more than 100 cases are found).
  • Female fraternal twins have higher chances of giving birth to twins.
  • They have different blood types.
  • If a woman has fraternal twins during the first pregnancy, there are higher chances of having fraternal twins in the next pregnancy.
  • Similarly, if a woman has fraternal twins as siblings, or in the maternal genetic line; she has more chances of giving birth to twins herself.
  • On the other hand, there are several factors that increase a woman's chances of conceiving fraternal twins. For example, older woman (above 35 years of age) give birth to twins more commonly than younger woman.
Famous Fraternal Twins
  • Alanis Morissette and Wade Morissette
  • Ashton Kutcher and Michael Kutcher
  • Aaron Carter and Angel Carter
  • Billy Dee Williams and Loretta Williams
  • Gisele Bundchen and Patricia Bundchen
  • Jenna Bush and Barbara Bush
  • Mario Andretti and Aldo Andretti
  • Mark Waugh and Steve Waugh
  • Mark Vincent and Paul Vincent
  • Scarlett Johansson and Hunter Johansson
Lastly, one of the interesting facts is that unlike other siblings, twins have a unique emotional bond between themselves that lasts for a lifetime.