Распределение групп крови.

We have learned a good deal about how common each of the ABO blood types is around the world.  It is quite clear that the distribution patterns are complex.  Both clinal and discontinuous distributions exist, suggesting a complicated evolutionary history for humanity.  This can be seen with the global frequency patterns of the type B blood allele (shown in the map below).  Note that it is highest in Central Asia and lowest in the Americas and Australia.  However, there are relatively high frequency pockets in Africa as well.  Overall in the world, B is the rarest ABO blood allele.  Only 16% of humanity have it.



Distribution of the B type blood allele in native populations of the world

The A blood allele is somewhat more common around the world than B.  About 21% of all people share the A allele. The highest frequencies of A are found in small, unrelated populations, especially the Blackfoot Indians of Montana (30-35%), the Australian Aborigines (many groups are 40-53%), and the Lapps, or Saami people, of Northern Scandinavia (50-90%).  The A allele apparently was absent among Central and South American Indians.



Distribution of the A type blood allele in native populations of the world</p>

The O blood type (usually resulting from the absence of both A and B alleles) is very common around the world.  About 63% of humans share it.  Type O is particularly high in frequency among the indigenous populations of Central and South America, where it approaches 100%.  It also is relatively high among Australian Aborigines and in Western Europe (especially in populations with Celtic ancestors).  The lowest frequency of O is found in Eastern Europe and Central Asia, where B is common.



Distribution of the O type blood in native populations of the world

http://anthro.palomar.edu/vary/vary_3.htm