A few years ago, I got to thinking about blood type. I wondered how come I have B+ blood when everyone in my family is O or A. I decided to go hunting on the Internet to see if I could learn something about where I come from using this tidbit of information.

It turns out, B-type people are universally less common than O and A.

It might mean I have some tidbit of Asian ancestry. Genghis Khan made serious inroads into Europe. Who knows where the seeds of his army were left?

The incidence of type B is low amongst Jews. Low everywhere, but not unheard of, nor so infrequent as to be rare. But low.

My mother was type O, the most common blood group everywhere. Among native peoples in the western hemisphere, type O is close to 100%. Many scientists theorize that “O” was the “original” human blood type and all other types mutated from it.

That’s one theory, anyhow. Blood types do mutate and occasionally even change completely following a transfusion.

This is a bit of a hot topic because some places, blood typing has been used to categorize people as inferior, notably Japan. There are always racists looking for a way to prove they are superior to everyone else. At least one study (I’m not sure I should dignify it with that name) claims people of B-type blood are descendants of Neanderthals while O and A descended from Cro-Magnon.

This is pure speculation. Not research.

Worse, there are pockets of racists who contend that A is the only pure Aryan blood type. What evidence did they base this on? None. Particularly interesting since O is the dominant blood type everywhere.

Overall in the world, B is the rarest ABO blood allele. Only 16% of humanity has it. It reaches its highest frequency in Central Asia and Northern India. It’s believed to have been entirely absent from Native American and Australian Aboriginal populations prior to the arrival of Europeans. However, there are relatively high-frequency pockets in Africa too. 

B is not a dominant blood type anywhere. It is highest in the Philippines and Siberia, the lowest in the Americas. Very rare in the British Isles and Scandinavia. The highest percentage it reaches is 38% of the population and that is in the Philippines. In the Middle East, the ultimate melting pot, all the major blood types are more or less evenly divided in the population.

If this shows some kind of migratory pattern for our ancestors, no one can prove it. Not yet, anyway, but they are working on it. The Middle East is the land pathway between Africa, Europe, and Asia, so it makes sense that many types of people might make their homes there.

It turns out there is no universally accepted theory of the origins of man. Scientists and other theorists can’t even agree whether or not we all have the same progenitors.

So after all this, I don’t know much more than I did when I started. Clearly, there is something to be learned from the distribution of blood types in the world, but no one is certain of exactly what.

One of the possibilities of my “B” blood type is that my father was mistakenly typed and rather than A, was actually AB. But the truth is that blood types do sometimes pop up unexpectedly. There are lots of recessive traits lingering in us. My B+ blood has a number of unique qualities, which is why I have a blood donor card that specifies the unique other qualities of my blood.

In fact, the blood types we know – O, A, AB, B – in both positive and negative forms are not the whole of blood-typing. It gets a lot more complicated than most people realize, which is why there are whole hospitals dedicated to dealing with blood.

I think eventually blood typing will be one of the many ways we trace the movements of our Neolithic ancestors. Maybe even pre-Neolithic.