THE BLOOD TYPE.

The true origin of blood groups remains a mystery to this day due to a vast span of human existence of which little is known. The impermanence of our physical existence is responsible for this void; our flesh and body fluids rapidly decompose after death. Unless preserved by extraordinary means, even skeletal remains eventually crumble and disappear. What can be said for certain is that type O occurs unanimously in the Americas and Africa, while type B is most common in Asia and type A in Europe.
Today's researchers see that the key to understanding blood groups is in the particular characteristics possessed by each group. Scientists and anthropologists have begun using blood groups as markers in the search for humanity's imprint on our distant past. This studies have allowed a greater understanding of the movements and groupings of early peoples as they adapted to changing climates, mutating germs, and uncertain food supplies.
The variations, strengths, and weaknesses of each blood group can be seen as part of humanity's continual process of acclimating to different environmental challenges. Most of these challenges have involved the digestive and immune systems.
Many of the distinctions of today effects between blood groups in the survival against most forms of epidemic illnesses is so distinct and involve basic functions of our digestive and immune systems. For example, people with type O blood possess greater immunity to malaria. Also they are known to be more resistant to the flukes and worms, and they are the only blood group with antibodies against two other antigens, A and B.
A modern day map of the ABO blood group distribution in Europe parallels the location of major epidemics, with higher densities of blood group A and lower frequencies of blood group O in areas historically known to have had long histories of repeated pandemics. Scientists now believe that the reason for such immunity is that this blood group O developed in Africa millions of years ago as an evolutionary response to environmental diseases.
Also people with type B blood possess a higher degree of immunity to the plague and the reason is that this blood group developed in areas where that illness was especially devastating.
Although evidence points to the fact that the individual genetic mutations that produced the ABO genes are quite ancient, this is trivial in importance with regard to the actual demographics of the individual ABO groups in ancient populations. In genetics it is not the actual age of the gene that matters, instead it is its frequency or drift, considering that the force acting on the population is random mating. The gene frequencies remain unchanged constant, so something other than random mating is responsible for the present day differences in frequency between the ABO blood groups.
The answer lies in the discreet interactions that occurred between early man and his environment that were under the influence of his specific blood type group. These included the areas and climates he chose to inhabit, each with their unique populations or microbes and foods that he chose to catch and cultivate. As they migrated and were forced to adapt their diets (physically, mentally and spiritual) to local conditions, the new diets provoked changes in their digestive tracts (emotionally) and immune systems (illnesses), necessary to survive and later thrive in new habitats (strength and courage).
Different diets metabolize in a unique manner by each blood group resulting in that specific blood group achieving a certain level of susceptibility (good or bad) to the endemic bacteria, viruses, and parasites (negative energies) of the area. This is, probably more than any other factor, what influences the modern day distribution of our blood group. This results from the fact that many microbes (negative energies) possess blood types of their own. Our blood antigens are not unique to us, although we are the only species with all four variants. A bacteria which for example possesses an antigen on its surface that mimic a specific blood type antigen has a much easier time infecting the person since the bacteria would be considered 'self' to the immune system of that specific blood group. Also microbes may adhere to the tissues of one type of the blood groups in preference to another, by possessing specialized adhesion molecules for that particular blood group.
The Black Plague (a powerful negative energy) which ran unchecked throughout Europe in the 13th and 14th centuries, is a perfect example. The Plague was a disease caused by bacterial infection and was almost certainly fatal to those who contracted it in early years of its initial spread. By the 15th century, however, fatalities were rare, although many people continued to contract the infection. In just 2 generations, traits were developed in the survivors that protected them from fatal infections. Since these trails were necessary to survival, they were then passed on and retained as a form of genetic memory.
The extraordinarily high percentage of blood group O in ancient or otherwise isolated populations testifies to its great advantage over the other groups. Even though the early migrations dispersed the gene for group O throughout the world, there are some extraordinary examples of 'old' populations existing in our world today, like the one called, the People of the Andes. Because of their geographic locations, these societies have remained isolated from interaction with other populations and city oriented life. If A, B, and O had developed simultaneously, the isolated population groups would have had all of them. But these 'old societies' are group O because genes for the latter blood groups never had the opportunity to enter into their populations. They have remained unchanged.