Specifics of the twins fifth

fact №1
When twins are born?
9 In each pregnancy. Most often twins born blacks, and very rarely - the representatives of the Asian race. The probability of the birth of twins (especially monozygotic) increases with maternal age - it becomes the maximum at 40, and then decreases. This feature of the body may be associated with higher levels of gonadotropins. Many of the women who were treated for infertility with gonadotropins subsequently born twins.
Popular belief that twins are born in clean generation error. Genetic predisposition to the birth of the twins really exists, but it can occur in generation.

fact №2
Does the place of birth of twins?
According to statistics, at least the twins are born in the industrial cities. The notion that the environment influences the birth of twins is also a delusion. But there are curiosities. In a small Indian village known as the "village of the twins" are about 70 pairs of twins. And every year it increases. Scientists can not explain this phenomenon, and these Indians believe that it is the work of Lord Ram, who had twin children.

fact №3
"City of twins"
There is also an artificial place for concentration of twins - Tuinzbarg in Ohio. Every year in this city held a celebration in which the twins arrive at different ages.

fact №4
Two or two
The twins are monozygotic and dizigotni. Dizigotni are if they are immediately fertilized two eggs (zygotes) and monozygotic - if only one fertilized egg, but then it is divided.
Monozygotic twins are always of the same sex, they fit all genes, while dizigotnite these matches are only 50%.

fact №5
Siamese twins

These are monozygotic twins, in which the division has begun at a later stage and therefore they are born joined. The compound may be insignificant - for example, a skin fold, but they can also be a connate bone.

fact №6
The method of twins
For the first time the twins science is interested in the 19th century. In 1876 the Englishman F. Galton posted his scientific work "History of twins as a criterion of the relative influence of nature and nurture." Since that time hundreds of experiments using the "method of the twins," which today is the main way of collecting information on the role of heredity and the impact of the environment on man.
The most reliable embodiment is the study of monozygotic twins separated occurring after about 15-20 years. Although living in different families and receive different education, they are equally energetic, love the same books and movies suffer from the same diseases. Meeting, they became close friends and believe that hardly differ from each other.