Prepare for Trouble, and Make it Double

To protect the world from devastation! To unite all peoples within our nation! To denounce the evils of truth and love! To extend our reach to the stars above!

I have a little brother. He was six once. Therefore, yes, I did just quote Pokemon. Almost from memory.

This week, I want to talk about twins. While I'm not entirely sure whether or not Jesse and James are twins, I do know that they are two people who are roughly the same height and look similar, and seem to do a lot of things together, so I think of them as sort of twins.

I think twins are really cool. I really want one. People with twins probably don't agree with me on this, but it would be awesome to have a person who is your sibling but also the same age as you and probably one of your really good friends.

But scientifically, what are twins? And, more importantly, do twins have super magical twin telepathy?

According to wikipedia, twins are defined as "one of two offspring produced in the same pregnancy". There are two different types of twins: monozygotic, or identical, and dizyotic, or fraternal. Zygosity is just a measure of how identical twins are.

You can have boy-boy identical twins or girl-girl  identical twins. Statistically, female-female twins are more common than male-male twins. Boy-girl identical twins are extremely rare, as less than ten cases have been confirmed. In addition, the girl would probably have turner syndrome, which is when a female is missing part of one of her X chromosomes. (Just a very brief biology lesson-- women have two X chromosomes, men have one X chromosome and one Y chromosome).

Identical twinnings occur when a fertilized egg splits into two separate embryos. Because the egg has already been fertilized, both twins have pretty much the same DNA, so they look identical. They have different fingerprints, though, because their fingers were pressing different parts of their mother's womb, and, apparently, that's how fingerprints are created. The chance of having identical twins is about 3 in 1000.

There are also semi-identical twins, where they get the same amount of genes from one parent and unequal amounts of jeans from another parent. 

Fraternal twinnings are more common, about  6 per 1000 births to 14 per 1000 births.It happens when two eggs are fertilized by two separate sperm. They have the same similiraity in DNA and looks as normal siblings.

There are other twin-eque conditions of pregnancy, including

• vanishing twin, which is when one twin dies early into the pregnancy
• conjoined twins, which happens when an egg doesn't split all the way. They're also known as siamese twins. They're pretty self-explanatory. 
• parasitic twins, which is when one twin fetus causes problems for the other twin fetus because it's not fully developed. Sometimes this has to be surgically remidied. 
• chimerism, which I don't understand exactly, but basically means that chromosomes from multiple organisms are mixed.
• twin-to-twin transfusion syndrome, which is when one twin is pretty much stealing blood from the other
• a lot of other ones, too. You can Wikipedia them if you want. 

The higher number of multiple births you get, the rarer and more potentially dangerous they become. Twins are fairly common,  triplets are less common, and anything more than that is very rare. No nonotuplets (9 birhts) have survived infancy, and one one set of octuplets, the Suleman octuplets, have survived.

Here's a short video from CBS about a group of septuplets. They're one set of the very few surviving septuplets in the world.

Twins are also very useful for scientific experiments. Since identical twins have the same DNA, they can be used to test the difference of genetic and environmental factors. This can help scientists determine the cause for many diseases, personality trait, and personal tastes to better understand both genetics and the human brain. 

 But do these multiple sets of babies have a special bond?

There are so many stories about a twin who gets a random, agonizing pain when the other has just gotten into a car crash, or twins finishing eachother's sentences, or knowing what the other one is thinking; however, that might be from living together and being so similar more than actual telepathy. Their similarities and familiarities with one another might subconsiously allow them to predict how the other one might react in a certain situation or empathize so much with their pain that they feel pain as well. There is no scientific evidence to support the idea of twin telepathy at all.

Perhaps as science expands, scientists will be able to determine the bond between twins. Until then, there are a lot of questions that they still have not just about how twins' minds work, but how their genetics work. And how they can harness their superpowers to fight crime and save the planet. Or not. You never know...