act@pur-phy.UUCP (Alex C. Tselis) (12/12/84)
There have been some inquiries about the distribution of blood groups among humans. I have a reference which may be informative in this regard. The reference is : Daniel L. Hartl, HUMAN GENETICS, Harper & Row, New York (1983) On pages 436-437 he gives maps which show the frequencies of the A B I and I alleles among the aboriginal populations of the world. (The A and B here are superscripts.) The blood cell antigens are determined by one locus on the ninth chromosome, and there are alleles of three types: IA, IB and IO (I won't use superscripts any more; too tedious to type them in.) If a person's genotype is IA/IA or IA/IO, then their red blood cells (RBCs) carry type A antigen, if their genotype is IB/IB or IB/IO, then their RBCs carry type B antigen. If their genotype is IA/IB, then their RBCs carry both type A and type B antigens. Therefore, they have type A, type B and type AB blood, respectively. If the genotype is IO/IO, then their RBCs do not carry either antigen, and their blood type is O. Some of the statistics given in the book (this may repeat previous postings; if so, sorry) are: Among Caucasians: Type A 42% Type B 8% Type AB 1% Type O 48% Among Chinese(there was nothing about other Asians): Type A 31% Type B 28% Type AB 7% Type O 34%