By Peter D’Adamo
It would be tidy if all people who were blood group O lived in one part of the world, and all blood group A in another. But this does not happen. The various blood groups are found pretty much all over the planet. However they are not found in the same frequency everywhere. It was this difference in the frequency between the blood groups that gave the early blood group detectives their first insights into a tangible form of human individuality.
Soon after the ABO blood groups were discovered by Karl Landsteiner in the early 1900’s, scientists began to think about using them as a tool to help study the differences between different populations. One of the first to begin using blood group in this manner was a husband and wife team, Ludwik and Hanka Hirszfeld. During World War I, they took blood samples from the soldiers of three continents then assembled in the area of Greece called Macedonia as “The Allied Army of the East.” In reality this army was a hodgepodge of battered contingents and survivors from various Allied nations that did little more than stay put in camp and suffer from constant epidemics. However the Hirszfelds realized that the international nature of this army presented opportunities of examining the serological properties of the blood of a large number of soldiers or civilians belonging to very different races.
They established three categories: One marked by a high percentage of subjects of blood group A and a low percentage of blood group B, which seemed to include the majority of European races (European type); a second showing, on the contrary, a high percentage of blood group B and a low one of blood group A, comprising Asians and Ethiopians (Asian-African type); and a last category containing approximately equal quantities of blood groups A and B made up of Russians, Turks, Arabs and Jews, which they called an intermediate type.
The Hirszfelds invented an interesting and useful tool called the Hirszfeld Biochemical Index and which conveniently lets us express the ratio of blood group A to B in any population. The formula is very simple; you add up the number of blood group A and AB individuals in a population and then divide it by the number of blood group B and AB individuals. As so:
Hirszfeld Index = (A + AB) /(B + AB)
Thus, the higher the Hirszfeld Biochemical Index of a population, the more blood group A people in that population over blood group B people in it; the lower, the more blood group B over A. The highest number in the Hirszfeld Biochemical Index (most As, least Bs) was found among the English troops (4.5); the lowest (most Bs, least As) were found in the Indian (0.5) and Vietnamese troops (0.8).
The work of the Hirszfelds would look crude in comparison to later, more sophisticated methods, and it suffers from the problems of all single-gene examinations of human diversity, that is there are no “pure races” to be identified by a single marker. But their discovery, published in 1919, did give rise to a considerable number of subsequent investigations, producing an enormous mass of documents of varying merit.
The Hirszfelds themselves were a parable of how fluid ethnic affiliations can be: Polish Jews who were attached to the Serbian army through the University of Zurich. They later converted to Catholicism, but were nonetheless confined to the Warsaw Ghetto, where Ludwik gave illegal lectures on medical topics including one on blood groups and race. Yet they managed to survive into a world in which, due to the recent oppressions having been based solely on grounds of ‘blood,’ race was a guilty and discredited notion.
Image: Odilon Redon, ‘Flower of Blood’ (1895)
- Excerpted from: D’Adamo PJ. ‘Archeogenetics’ in: Fundamentals of Generative Medicine, Volume I (2010) Drum Hill Books, Wilton CT USA
- Ludwik Hirschfeld on the Individualist