Why is Siamese or conjoined twins part heredity and part environment?

Question

I'm not sure if this is even right but my teachers have told me this...so I just need to know why. Thanks!!!!

Answer 1

The way that i understand it is: two eggs drop down into the uterus and are fertilized by the male, you will have twins,but sometimes the eggs are attached together and you will get

Siamese twins, then sometimes one egg is inside another an grow,then you have a baby

growing inside of each other. I do not know the

answer,but i think more of the environment causes it than heredity is my view of it. research the item on the computer type in Siamese twins and read it and come to your own conclusion. sometimes nature goes wrong then everybody wants to blame someone or something for the mistakes or errors in nature.

Answer 2

Well, it is part heredity because sometimes there is just a natural tendancy in the blood line.  A lot of times there are other sets of conjoined twins either with the parent or within the family somewhere.

It can be genetic because it can sometimes be caused by a genetic defect in the egg or sperm or the fetus itself.  

I can also be environmental because in some cases it can be a defect caused by something the mother has done during her preg, either intentional or not, aware or not.  I am not saying mothers should be 'blamed' so to speak, because they may not realize they were doing anything they shouldnt, but it does happen.

And other times it is just a fluke and they dont know why it happened.

Search wikipedia, they have some good info

Answer 3

Never heard of either factor playing a part. These cases are just nature´s mistakes.Try looking it up in Wikipedia.