What blood type is the rarest

There are four blood groups, referred to by the absence or content of specific substances (antigens) type A and type: I – 0 (antigens are absent), II – A (present the antigen of type A), III – V (in blood there is antigen b type), IV – AB (contains both of these substances).

The blood is also klassificeret the presence or absence of the RH factor. The RH factor is the antigen located on the surface of red blood cells. The most rare blood type is determined by both indicators. According to statistics, this is the status of the fourth group with a negative RH factor. She has a less than one percent of the population (mostly women).
Allowed to pour the same blood group and RH of the patient and the donor. When absolutely necessary is allowed to transfer to other groups, the first group of blood with the same RH factor.

How did the fourth group of blood

According to scientists, in ancient times almost all people have one blood group - the first, and so it is the most widespread on most continents. Due to mutations emerged second and third blood group. Such mutations arose from the adjustment of the organism of the primitive man learned to eat other than meat, fish, berries, leaves, vegetables. According to scientists, the third group of blood appeared on the territory of South-Asian countries where people eat food derived from animals (milk, cheese, cheese, cured meat and so on).

The rare fourth group appeared no more than 10 centuries ago, the reason for its occurrence still remains unknown. However, there are suggestions that it was the result of racial mixing. Because such marriages are rare, people with the fourth blood group, very little. There is also an opinion that this blood type emerged from the significant increase over the last five hundred years in the human diet products subjected to heat treatment, as well as synthetic and semisynthetic foods.
According to one version, the fourth group of blood is formed due to the destruction of the human body viral infections.

People with a fourth blood group has a unique ability to adapt to the conditions of nutrition and environment, and their body has a high resistance to diseases. These people have a sensitive digestive system and very tolerant immune system.