We know about how people donate their body after death to hospitals and health research centres for possible use of the healthy organs to the needy ones. And a very common such donation is the cornea of the eye. But even when one is alive, he/she can donate blood. Many cities across India have what are called ‘blood banks’, where blood gathered by donation from blood donors is saved and preserved for later use in blood transfusion.
How much blood can one donate? Blood in a healthy human body is about 7% of the total body weight (the average body weight being 55-65 kg), or 4.7 to 5.5 litres (1.2 to 1.5 gallons).
In a regular donation, the donor gives about 500 ml of blood, and this is replaced in the body within a day or two (24-48 hours). Blood types are determined by the presence (or absence) of certain antigens (molecules that can trigger an immune response), if they are foreign to the body of the recipient. Thus, a matching of the blood type of the donor with that of the receiver is necessary.
Blood types
What are these blood types? They are classified as antigens A and B in our red blood cells. Landmark research on these was done by a medical doctor, Dr. Karl Landsteiner of the University of Vienna in Austria. He collected blood samples from several of his staff members and found that the serum of some of them led to the clumping together (or precipitation), while others had no problem with the donor serum. Using this information, he defined three acceptable types of blood cells which he called as A, B and O blood types. We still use these classifications to this day.
Dr. Landsteiner received the Nobel Prize in physiology/medicine in 1930. A very informative review on Dr. Landsteiner’s work has been published by two Iranian scientists, Dr. Dariyush D. Farhud and Marjan Zarif Yeganeh in Iranian Journal of Public Health, Vol. 42, No. 1, Jan. 2013, pp. 1-6., wherein they estimate that the blood group A in India to be about 40%, blood group B between 25-35% and group O to be 40-50%.
A recent detailed paper by two scientists from AIIMS, New Delhi, Dr. G.K. Patidar and Dr. Y. Dhiman (ISBT Science Series (2020) O, 1-12) has analysed several reports on the distribution of A, B, O and AB blood groups in India to be 23%, 34%, 35% and 8%, respectively, and that the Southern States have higher O group, about 39%.
The Neandertals
In 1964, the Italian population geneticist Dr. Cavalli-Sforza worked not only with his colleagues to check on the prevalence of blood groups A, B, O and AB in Italy and its neighbours, but also contacted several colleagues across the world, and together published a phylogenetic tree of 15 human populations, and the prevalence of blood groups distributed across the continents of North and South America, South Africa, and Polynesia in the far East.
In addition, he was also able to obtain fossils of Neandertals and Denisovs, from heritage sites in Europe, roughly between 40,000 to 1,00,000 years ago. His group could then classify these populations with blood groups A, B, O and AB. And the latest paper by Silvana Condemi et al., in PLOS One, July 28, 2021, titled, “Blood groups of Neandertals and Denisova decrypted” point out that blood group systems were the first phenotypic markers used in anthropology to decipher the origin of populations across the world, as aboriginal humans migrated to various parts of the world (Eurasia, Sub-Saharan Africa, Australia and Papua, and other places).
Analysis of the blood group markers of some Neandertals and Denisovans showed the presence of the ABO group, and also some other markers that are used today in blood transfusion.
Primate monkeys
Interestingly in their paper, Dr. Farhud and Dr. Yeganeh also quote a report published by Dr. P. Kramp in Primatologia III (1960) Basel which reports that primates (chimpanzee, gorilla, orangutan, gibbons) also have blood groups containing AB, A, B and O, just as we humans have.
Indeed, we owe our blood types (A, B, O, AB), thanks to what our primate monkey ancestors had millions of years ago. Just think about it. Our blood is our heritage, just as our genes are — from monkeys to archaic humans and our ancestors to today. Hanuman of Ramayana not only helped Goddess Sita by bringing her to the safety of her home, but has also blessed us with our blood groups.
(dbala@lvpei.org)
- How much blood can one donate? Blood in a healthy human body is about 7% of the total body weight (the average body weight being 55-65 kg), or 4.7 to 5.5 litres (1.2 to 1.5 gallons).
- Blood types are determined by the presence (or absence) of certain antigens (molecules that can trigger an immune response), if they are foreign to the body of the recipient.
- Analysis of the blood group markers of some Neandertals and Denisovans showed the presence of the ABO group, and also some other markers that are used today in blood transfusion.
