The INDIVIDUALIST

A Wiki about biochemical individuality

Paleoserology

Attribution

Excerpted from the Complete Blood Type Encyclopedia by Peter D'Adamo, published by Penguin Putnam Inc, Copyright 2002

See Also

Introduction

There is a vast span of human existence of which little is known. Archeological ruins from the beginnings of civilization have been unearthed, and there have been occasional discoveries of a more prehistoric nature, but not much else. The impermanency 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. Early peoples did not practice ceremonial burial. Left to the elements, bodies soon completely decomposed: "Dust to dust" was not a mere poetic metaphor. It was a recorded observation of our transient natures.

Only in the last century have scientists and anthropologists begun using biological markers such as the blood groups in the search for humanity's imprint on our distant past. These 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. Recent analyses, using sophisticated genetic measures, have produced the most accurate picture to date of human evolution.

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. It is no surprise, then, that many of the distinctions between the blood groups involve basic functions of our digestive and immune systems.

Evolution is usually considered in the context of millions of years, which is the time frame needed to explain the many differences between animals or other species. Yet humanity's own life span provides ample time for the myriad number of small day-to-day refinements, representing the constant struggle between inherited traits and environmental challenges.

And, although evidence points to the fact that the individual genetic mutations that produced the ABO genes are quite ancient (1) this is trivial importance with regard to the actual demographics of the individual ABO blood groups in ancient populations. In genetics it is not the actual age of the gene that matters, it is its frequency or drift. This is computed by geneticists using a formula called the Hardy-Weinberg equation. Hardy-Weinberg posits that if the only evolutionary force acting on the population is random mating, the gene frequencies remain unchanged constant. In essence if you start off with a small number of a particular gene in a larger gene pool (such as the gene for blood group B in the gene pool for ABO blood type) and nothing other than random mating occurred, at the end of a period of time, you would still have a small number of B genes in the ABO gene pool.

So something other than random mating is responsible for the present day differences in frequency between the ABO blood groups; why for example, are there such large populations of blood group O (40-45%) and A (35-40%) versus much lower rates of groups B (4-11%) and AB (0-2%)?

First, it can be said that perhaps the mutation that produced the B gene was just not as common an occurrence as the mutation that produced the A gene. Yet, if they occurred at the same time, why would this be? Also, if the mutations are of such paramount importance, why is the distribution of the B gene so geographically limited to an area of high concentration stretching as a belt of territory from the Himalayas to the Urals?

The answer lies not in the ancient nature of the mutations that produced the A and B genes, but rather in the discreet interactions that occurred between early man and his environment that were under the influence of his ABO blood group. These included the areas and climates he chose to inhabit, each with their unique populations of microbes and foods that he chose to catch or cultivate.

As humans migrated and were forced to adapt their diets to local conditions, the new diets provoked changes in their digestive tracts and immune systems, necessary for them to first survive and later thrive in their new habitats. Different foods metabolized in a unique manner by each ABO blood group probably resulted in that blood group achieving a certain level of susceptibility (good or bad) to the endemic bacteria, viruses and parasites of the area. This probably more than any other factor was what has influenced the modern day distribution of our blood group. It is fascinating to note that virtually all the major infectious diseases that ran so rampant throughout our pre-antibiotic history have ABO blood group preferences of one group or another.(2)

This results from the fact that many microbes possess ABO "blood types" of their own. It is perhaps useful to understand that the ABO blood group antigens are not unique to humans, although humans are the only species with all four variants. They are relatively simple sugars which arte abundantly found in nature. A bacteria which for example possessed an antigen on its surface that mimicked the blood group A antigen would have a much easier time infecting a person who was group A, since that bacteria would more likely be considered "self" to the immune system of a blood group A person. Also microbes may adhere to the tissues of one ABO group in preference to another, by possessing specialized adhesion? molecules for that particular blood group.(3)

The horrors of the Black Plague, which ran unchecked throughout Europe in the thirteenth and fourteenth 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 the early years of its initial spread. By the fifteenth century, however, fatalities were rare, although many people continued to contract the infection. In just two generations, traits were developed in the survivors that protected them from fatal infections. Since these traits were necessary to survival, they were then passed on and retained as a form of genetic memory.

The Black Plague is especially interesting from a perspective of the ABO blood groups, since Yersinia is a bacteria with a preference for individuals of specific ABO group, in this case, group O. (4,5)

The effects of ABO blood group on survival against most forms of epidemic illness is so distinct that a modern day map of the ABO blood group distribution in Europe closely parallels the locations 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.

On the other hand, in pre-urbanization days the survival advantage would have laid with blood group O as they are known to be more resistant to the flukes and worms that routinely parasitized these early humans, probably because they are the only blood group with antibodies against two other antigens, A and B.

These changes are reflected in the local success or failure of each of the blood groups, which appear to have each had a moment of pre-eminence at a critical juncture in our history. The ascent of humans to the top of the food chain (the early advantage of blood group O), the change from hunter-gathering to a highly concentrated, urban environment and agriculturally-based diet (the ascent of blood group A), and the mingling and migration of the races from the African homeland to Europe and Asia ( the opportunity for blood groups B and AB).

Ancestral Foundations

From a purely scientific point of view, chemical analysis of the group O antigen reveals that from a structural perspective, it is the simplest blood group and it serves as the backbone for the synthesis of increasingly complex A, B and AB. These later blood groups evolved by adding other sugars onto the basic O sugar, much like a modern city might be built upon the foundations of an ancient one. Thus if the mutations that produced the A and B antigens are ancient, the gene for blood group O is infinitely older.

Another dimension testifying to the great antiquity of group O comes from the science of physical anthropology and suggests that a greater part of humanity's existence has been lived exclusively as group O.

New studies on Mitochondrial DNA (mtDNA) support the theory that Homo sapiens emerged in Africa and only later infiltrated other regions. Unlike DNA, which is inherited from both parents and changes minutely with each generation, mtDNA is passed directly from mother to child. It is contained in eggs but not in sperm. Since only random mutations alter its sequence, it is a more accurate measure of the trajectory of human evolution. Extensive mtDNA studies demonstrate that humans evolved from a common ancestor. These studies also confirm the theory that the blood groups evolved as migratory mutations.

The extraordinarily high percentage of blood group O in "ancient" or otherwise isolated populations also testifies to its great age. (6) Even though the early migrations dispersed the gene for group O blood throughout the world, there are some extraordinary examples of "old" populations existing in our world today. Because of their geographic locations, these societies have remained isolated from interaction with other populations. 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 later blood groups never had the opportunity to enter into their populations. They have remained unchanged.

The Basques are an ancient people whose origins are still a mystery. The Basque language, the only western European language not connected by Indo-European roots, appears to be related to several dialects found in small isolated populations in the valleys of the Caucasus Mountains. Although they look much like their French and Spanish neighbors, Basques possess the lowest frequency of blood group B---originally having no group B at all---and the highest frequencies of blood group O in Europe. Cattle, abundant on the European plains, and fresh water fish seem to have been the staples of their early existence, as evidenced by the extraordinary renderings of the famous cave paintings found in the Basque country.

More than fifty percent of the Basque population is Rh negative, as opposed to sixteen percent for the rest of Europe. Like the gene for group O, the genetic mechanism for the Rh negative blood type is simpler, hence undoubtedly older, than the gene for Rh positive.

Native Americans are another example of the "old peoples" existing in our world today. It has often been asserted that all full-blooded American Indians are group O, and recent studies on largely intermingled Amerindian populations show a very high (sixty-seven to eighty percent) predominance of O, indicating that their migration from Asia to Alaska was probably much earlier than previously believed.(7,8) Their high rate of blood group O suggests that the Amerindians and Eskimos are directly descended from Cro-Magnon ancestors, probably Mongolians, who migrated around 15,000 B.C. to the Americas. In contrast to the Basques, however, the Asian Amerindians must have mingled extensively with other Asian populations, picking up along the way the gene for Rh positive blood.

As with the Basques, few Native Americans are group B, so they must have migrated to the Americas late enough to pick up the Rh positive gene, but too early to pick up the gene for B. (9) This migration probably took place across the land bridge that at one time connected Siberia to Alaska. As the last Ice Age ebbed and the lands warmed and glaciers receded, the rising water levels eliminated the land bridge between Asia and American, bottling up the Native Americans and a high-O enclave and preventing for another 10,000 years any communication between the continents. Forensic studies support this theory: in Chile no B or AB have been noted either in pre-Columbian or Colonial mummies. (19)

Another theory for the extremely high incidence of blood group O in Native Americans is that O individuals seem relatively resistant to syphilis and smallpox, major killers of Native Americans that were introduced into the Old World by Columbus. (22)

Agricultural advances in the Americas were late in coming, because the new American homeland was abundantly populated with game and fish, which discouraged agriculture. Even corn, which was the staple grain, didn't appear to be domesticated until 4500 B.C., and common beans appear to be an even more recent addition, first being cultivated around 2200 B.C. So, like the Basques, meats and not grains were the primary staple of the Native American diet.

In England, Wales and Scotland there is a strong association between [ABO blood group]? and geographical differences in the death rate (10) Studies of blood group distribution in the British Isles show a general increase of group O frequency from relatively low numbers in southern England to increasingly higher ones in northern England, Wales, Scotland, and Ireland. (11) This suggests that the Anglo-Saxons had relatively high A levels, and that O increased as the proportion of Celtic ancestry increased, although the origin of the high incidence of blood group O in the Irish may represent the remnants of Mesolithic peoples. (23) This is also the case with continental Europe, where the percentage of group O increases in northern Germans and Danes. It is also known that the Icelanders had high O frequencies, close to those frequencies found in the populations of Scotland and Ireland.

Among the Nomads of the Arabian Peninsula, and the Berbers of the Atlas Mountains, two old populations, the frequency of the blood group O gene is high. Africans, on average, have more O genes and less A genes than do Europeans. So it can be seen that the gene carried by people who are blood group O is ancient by evolutionary standards.

Hunter-Gatherers

Our first human ancestors likely emerged in sub-Sahara Africa between 170,000 and 50,000 years ago. These ancestors probably ate a rather crude, omnivorous diet of plants, grubs, and the scavenged leftovers of other, more successful predatory animals. Since humans have neither the sharp teeth or claws of a true predator, one could speculate that these people were perhaps as much prey as predator. Yet within these early humans lay the greatest predatory tool yet devised: The human brain.

In a study reported in the journal Science, anthropologists said their tests of the carbon content of teeth of Australopithecus africanus indicate that these individuals ate large quantities of food rich in carbon 13 - like grasses and sedges - or animals that ate these plants, or both. The research indicated that the australopithecines, which walked upright but also climbed trees, were already venturing out of their usual forest habitat to forage in open grasslands. It also suggested that hominids were consuming high-protein animal foods before the development of stone tools for butchering. They noted that many theories of human origins invoke a switch to a meat-rich diet to explain the sudden expansion of brain size with the first Homo species. If they were eating meat, it probably came from small animals that could be caught without tools or the scavenged remains of meals left by large predators. (12)

Perhaps I am not alone in recognizing the paradoxical nature of a high meat diet being the driving factor behind the dramatic growth of the human brain, the result being the production of nutritionists who advise a [Veganism? vegetarian] diet for virtually everyone.

Big game hunting by humans started in Africa about half a million years ago, although the full force of armed human bands may not have been felt much before 100,000 B.C

Early human's relationship to their environment changed dramatically with the appearance of our first direct ancestor, Cro-Magnon, around 40,000 B.C. Named for a site in France where remains were first identified and studied, Cro-Magnons developed the beginnings of communication and tool working, and were also superb hunters. Using simple signals and gestures, they began to hunt in organized packs, wielding bone or simple stone weapons. This major advance catapulted what had been one of the less successful primates all the way to the top of the food chain. As skillful and formidable hunters, Cro-Magnons soon had little to fear from any animal rival.

Cro-Magnons possessed such modern human features as a higher, vertical forehead, a reduced brow ridge, a smaller face and teeth, and a chin. Their skeletons indicate great muscularity, suggesting they were employed in much more strenuous activities than are most modern peoples.

By the time of the Cro-Magnons, hunting and the consumption of a mostly carnivorous diet had become a way of life. It was in the midst of this carnivorous frenzy that the digestive attributes of Blood Group O reached its full expression, with the highly efficient acid and pepsin production of the stomach geared for the digestion of meat. With no natural predators (other than themselves), and an assured supply of game, the population of wily, physically agile Cro-Magnon hunters must have flourished.

Once early humans had gained ascendancy, it took a surprisingly short time for them to deplete the numbers of major game animals. By 50,000 B.C., most large game herds were already extinct in Africa. The scarcity of a primary food source led to widespread migration in search of new and fertile hunting grounds. The feast had come to an end. It had been a fairly routine task to feed a small hunting group on the kill of a single enormous animal carcass for a week or more. Now, having to hunt and kill a sufficient number of small game, most of whom proved fast and elusive, was much more difficult. Hunger began to take its toll on the previously successful tribes of hunters. The young, old, and weak fell by the wayside, succumbing to disease and starvation. Bands of hunters began warring with each other for the limited food supply.

This depletion of the large game in Africa, coupled with climatic changes and possibly population pressures encouraged early humans to begin moving out of Africa. The more barren northern areas, previously covered with ice, had started to warm, while a shift in the trade winds began to parch and desiccate what had once been fertile land in the African Sahara.

All of these factors joined together into what was quite possibly the greatest series of migrations in human history. These migrations seeded the planet with a base population of blood group O, helping to make it the widespread and ubiquitous blood group it continues to be to this day.

Wanderings

By 30,000 B.C., bands of Cro-Magnons were migrating eastwards and northwards in search of new hunting lands. By 20,000 B.C., migration into Europe and Asia was so significant that large game herds began disappearing from those areas as well.

Other food sources had to be discovered, and the search was a desperate one. Under these pressures, our ancestors may have become omnivorous again, feeding on a broader menu of new plant and animal species. In particular, the food resources of the shore and the sea were systematically exploited for the first time.

Cro-Magnons were getting smarter and more creative, developing more sophisticated housing and clothing. These alterations allowed bands of hunters to search for new game herds in northern grasslands and forests. By l0,000 B.C., human hunting groups occupied all the main land masses of the earth, except for Antarctica. Hunting bands found their way to Australia between 40,000 and 30,000 years ago. Some 5,000 to 15,000 years later, other bands managed to cross the Bering Strait from Asia and entered the Americas. In these later, relatively more sophisticated hunting societies, the extermination of large game accelerated. Cro-Magnon hunting methods were becoming increasingly efficient, as evidenced by the vast number of animal bones piled up at some of the recently unearthed archeological sites. At Solutre, France for example, the remains of more than 10,000 horses have been found. At Dolni Vestonice in the Czech Republic, a large number of bones from extinct mammoths litter the site. Some archeologists estimate that from the time human migration to the Americas began about 15,000 years ago, it took less than one thousand years to exterminate most of the large game in North and South America. The reason that the Aztec civilization was so easily toppled by the Spanish Conquistadors was the sheer terror that the horse-mounted warriors brought to the relatively primitive Aztec foot soldiers. Horses were previously unknown to the Aztecs---in earlier migrations from north to central America, their ancestors had exterminated the wild horses of the American plains, slaughtering them for food. They had no idea that horses could be utilized to far greater purposes than as a food source.

The expansion of Cro-Magnon hunting bands across the earth has been called "a period of unalloyed success for humankind". The effect of a carnivorous diet on human growth was profound. The movement of the early humans to more temperate climates stimulated genetic responses. They developed lighter skins, less massive bone structures, and straighter hair. The skeleton, especially in Caucasians, matures slowly, and their lighter skin is better protected than darker skin against frostbite. Lighter skin is also better able to metabolize vitamin D, vital to survival in a land of shorter days and longer nights.

The dominance of the Cro-Magnons eventually brought about their own downfall. They suffered greatly from their own success. Overpopulation soon led to the exhaustion of available hunting grounds. Before long, most of the large game herds in the populated regions were destroyed by overhunting. This led to increased competition for a limited food supply. Competition led to war, and war to further migration.

Agricultural Dawning

The Neolithic Period, or "New Stone Age" followed the "Old Stone Age" or Paleolithic period of the Cro-Magnon hunters, beginning around 30,000 B.C. Agriculture and animal domestication are generally recognized as the hallmarks of its culture. The ability to cultivate grains and livestock allowed these early people to forgo the hand-to-mouth existence of their nomadic ancestors, and settle down in cities, allowing for substantial population concentrations. The British prehistorian V. Gordon Childe coined the term "Neolithic Revolution" to describe the change from a hunting and gathering society to one based on food production, and he considered it the greatest advance in human history after the marshaling of fire.

The Neolithic Period was also an important watershed in the distribution of the ABO blood groups. This new, relatively sedentary, agrarian lifestyle and the major change in diet resulted in a new mutation in the digestive tracts and immune systems of these early people. Many of them became carriers of group A blood. The blood group A variant allowed humans to tolerate and better assimilate grains and other agricultural products. Blood group A initially appeared in any significant numbers in the early Caucasian peoples, sometime between 25,000 and 15,000 B.C., somewhere in western Asia or the Middle East. The gene for group A was carried into western Europe and Asia during the movement of these Neolithic societies, especially a branch termed the Indo-Europeans, where it penetrated extensively into the pre-Neolithic Type O populations.

The Indo-Europeans appeared originally in South Central Russia, and between 3500 and 2000 B.C. spread southward into Southwestern Asia, especially to Iran and Afghanistan. At some point after this, they began to spread again, this time further westward, into Europe. Not only did their migration serve to transport the gene for group A to pre-Neolithic hunter-gatherers, but it also served as a major catalyst in stimulating the adoption of Neolithic developments, such as agriculture. Almost all modern Europeans share a common ancestry with the Indo-European peoples.

The invasion of the Neolithic Indo-Europeans was scattershot and incomplete. In some areas, pre-Neolithic societies were obliterated through warfare and intermingling, while leaving others, such as the Basques of Spain, relatively alone and intact.

The Neolithic Revolution was the original "diet revolution," as it introduced new foods and lifestyle habits into the simpler immune systems and digestive tracts of the early hunter-gatherers, and produced the environmental stress necessary to spark the development of a new blood group variation, A. As the digestive tract of this new blood group gradually lost its ability to digest the carnivorous diet of the hunter-gatherers, the simpler, pre-agricultural diet dependent largely on hunting and gathering disappeared.

The Collective

Settling into permanent communities presented new developmental challenges; the individualistic tendencies of the hunter-gatherer now gave way to a more structured society. Skill specialization can only evolve as part of a larger whole; the basket weaver is dependent on the farmer, the farmer on the toolmaker. One no longer thought of food only when hungry; fields needed to be sown and cultivated in anticipation of future reward.

The cultivation of wheat and barley, coupled with the domestication of food animals such as sheep, goats, pigs, chickens, and later cattle, first occurred between 9000 and 5000 B.C. in southwestern Asia, a fertile mixing ground in which all three major races co-mingled.

The new farming economies spread slowly from southeast Europe to the north and west. The permanent settlements that developed as a result of the new agrarian society gave rise to the early cities.

Neolithic sites in southeast Europe date from before 6000 B.C., and are located in areas with the most workable soils and temperate climate. Cattle, sheep, or pigs, in addition to wheat, barley, peas, beans, and flax, were raised. By 4000 B.C., a series of settlements were established on the lake shores of Switzerland, and agriculture was adapted to the Alpine environment, with emphasis on cattle, legumes, and fruit, in addition to wheat.

Cereal crops and cattle were introduced to western France by 4000 B.C., and were in use in southern Scandinavia, the British Isles, and in the northern European plains by about 3500 B.C., pushing the remaining hunter-gatherer peoples farther north into the wilderness, or influencing them to adopt the new, settled mode of life. 4000 B.C. marked the beginning of the Neolithic period in Britain and Ireland, and is denoted by an extensive clearing of the forests at that time for agriculture, burial rituals, and the building of "megalithic" structures, such as Stonehenge in England.

There is good evidence to support the link between the ascendancy of blood group A and the development of the urban society. As discussed, many areas of the world that have long histories of urbanization and frequent outbreaks of plague, cholera, and smallpox show a predominance of group A over group O. This statistic clearly proved that group A was more resistant to and able to survive the infections common to densely populated areas. One might well wonder how blood group O survived at all-much less how it has remained to this day the most ubiquitous blood group on the planet. One reason might be the sheer amount of group O in the gene pool; it is recessive in A and B and thus remains self-replicating.

Blood group A is found in the highest concentrations among western Europeans. Unlike blood groups B and O, there are many varieties of group A. The major grouping, A1, accounts for about ninety-five percent of all A blood. The largest subgroup, A2, is found principally in Northern Caucasians. A2 is found in very high concentration in Iceland and Scandinavia, particularly among the Lapps, ancient settlers of the area. They are almost unique in their high frequency of A, and have the highest frequency of A2, registering forty-two percent in one group. The A2 gene is almost entirely confined to Caucasian populations.

The European frequency of group A decreases as we head eastwards. Over much of Europe the frequency of the A gene is greater than twenty-five percent. It is also found in considerable numbers around the entire Mediterranean Sea, particularly in Corsica, Sardinia, Spain, Turkey, and the Balkans. It is clear that humankind most often laid down permanent settlements in those areas where conditions offered them the best chance of survival.

The Nomadic Mutation

The gene for blood group B first appeared in significant numbers somewhere around 10 to 15,000 B.C., the tail end of the Neolithic period, in the area of the Himalayan highlands now part of present day Pakistan and India. Like the environmental conditions which spawned the advent of group A, the development of blood group B was in large part a response to changes in the environment. But unlike A, which began to supplant group O as a response to new types of infections, then thrived as a result of the new dietary changes, group B appears to have been more of a response to climatic changes, followed by a different set of dietary adaptations. Life in the tropical flat savannahs of eastern Africa gave way to a harsher existence as the Cro-Magnon hunters migrated to the colder, drier, mountainous areas of the subcontinent and the barren endless plains of the central Asian steppes.

It is possible that blood group B may have been the only blood group with the capabilities to survive in such a harsh environment. There is some science behind this theory: For example, variability in the levels of the hormones testosterone, estradiol, and somatotropic hormones in mountaineers of the Pamirs and Kirghizes was examined in relation to their place of residence in terms of elevation above sea level. At high altitudes blood O group had had lower concentrations of estradiol and testosterone, blood group B the highest. (13)

Under times of famine, two biologic functions diminish: First is the ability to fend off infection. And the second is the ability to reproduce. Essentially omnivores, group B may have been the only blood group whose immune systems were capable of functioning with a diet described by one Roman historian as "soured milk and mare's blood." In addition to having the ability to survive pestilence, blood group B women may be more fertile than the A and O counterparts (14) and may begin to menstruate earlier. (15)

Higher concentrations of the group B gene exists in direct relationship with the demographics of the pre-existing caste system. Since the caste system was the direct result of consecutive layers of foreign conquest, it appears that the B gene may have been introduced into the Indian subcontinent via conquest. (16) In a study among fourteen Hindu caste groups, besides Christian and Muslim populations of West Godavari District, Andhra Pradesh, India All the Hindu castes except Brahmin, Kshatriya and Reddy exhibited relatively higher frequency of group B over group A (24) In a study of ABO distribution along the Silk Route of Northwestern China a distinct increase of blood group B was seen, especially when those subjects of Mongolian extraction were compared to Caucasian. (25)

An almost continuous belt of mountainous terrain extends from the Urals in Russia to the Caucasus in Asia, and then onto the Pyrenees of southern France. This barrier split the migrations of the blood groups into two basic routes; a northern stream and a southern one. The invaders taking the southern approach became the ancestors of the Mediterranean people and western Europeans, and carried with them the gene for blood group A. The Ural Mountains prevented a large migration westwards from Asia, although small numbers of Caucasians entered eastern Europe, carrying with them the gene for blood group B that they picked up by intermingling with the Asian Mongolians. This barrier served to divide blood groups into a western group, A; and an eastern group, B.

Blood group B Mongolians continued to travel northward, toward present day Siberia. They developed a different culture, dependent on herding, and emphasizing the use of cultured dairy products. These nomadic people were expert horsemen, and wandered extensively over the Siberian flat lands, the great Steppes. These nomads must have been compact, tightly knit, and genetically homogenous. A recent study using sophisticated polymerase chain reaction (PCR) technology determined the ABO groupings of on the dried remains of nine human mummies which had been discovered at Taklamakan desert in 1912. Of the nine, eight were group B. (17) At various times they penetrated large swaths of Eastern Europe, at one time reaching as far as the gates of Vienna, Austria. The Mongolians were certainly responsible for introducing the gene for blood group B into the eastern European populations.

Two basic blood group B population patterns emerged out of the Neolithic revolution in Asia: an agrarian, relatively sedentary population located in the south and east, and the wandering nomadic societies of the north and west. This schism stands as an important cultural remnant in Southern Asian cuisine; the use of dairy products remains practically nonexistent. To the Asian culture, dairy products are considered the food of the barbarian.

In the Middle-East it appears that tribes of Semitic group B nomads may have infiltrated into pre-existing Neolithic cultures, both passively and aggressively. Semitic peoples called the Hyksos were foreign rulers of Egypt during the Second Intermediate Period. Exactly who those foreign rulers were is not known, but it is assumed they were Asiatics. The Egyptian term for Hyksos merely means "rulers of foreign lands." It was once thought that foreign rule in Egypt would have necessarily entailed a violent overthrow, but instead there is the appearance of a peaceful takeover. More likely, the numbers of these foreigners slowly increased in the Delta region until they became a powerful political force. Under the rule of the Hyksos, the continuity of Egyptian culture and ritual was preserved, indicating that these foreign kings had become fully Egyptianized. Persian suzerainty may have also added large amount of B gene to the upper-class Egyptian gene pool, since a third century BC Egyptian mummy, 'Iset Iri Hetes' was recently typed and found to be group B. (18) Interestingly, Africa in general (independent of any racial categorization) has a higher incidence of group B than Europe or the Middle East. Whether this is the result of intermingling or the original B gene pool is unknown, however it does imply that the links between ancient Egypt and sub-Saharan Africa are deeper and older than generally recognized.

The blood group characteristics of the various Jewish populations have long been of interest to anthropologists. As a general rule, regardless of their nationality or race, there is a trend towards higher than average rates of blood group B. The Ashkenazim of Eastern Europe and the Sephardim of the Middle East and Africa, the two major sects, share high rates of group B blood and bear no discernible differences. Babylonian Jews differ considerably from the present-day Arab population of Iraq, in that they have a high frequency overall of group A, and an even higher frequency of group B blood.

The Jews of the Tafilalet Oasis in Morocco, an ancient community, now dispersed, also had a high frequency of the gene for blood group B, around twenty nine percent of the total society.

The Karaites, who have an extraordinarily high rate of blood group B, are members of a Jewish sect founded in Babylonia in the eighth century A.D. A singular community of Karaites continues to exist in Lithuania, and they were known to have migrated as a body from the Crimea. The Karaites consider themselves Jews by religion only, not by race. This claim of racial separation was accepted by the Nazi authorities, who controlled Lithuania during the Second World War. Because of this, the Karaites were spared the horrors of the Holocaust. (6)

To modern day anthropologists, blood group B continues to this day to be an "Eastern" blood group. It is found in high numbers among Asians such as the Chinese, Indians, and Siberians. In Europe, blood group B is more frequently found in Hungarians, Russians, Poles, and other eastern Europeans. It is not found in large numbers among western Europeans. Among pre-Neolithic people, such as the Basques and Amerindians, group B is practically nonexistent.

Of all the ABO blood groups, B shows the most clearly defined geographic distribution. Stretching as a great belt across the Eurasian plains and down to the Indian subcontinent, blood group B is found in increased numbers from Japan, Mongolia, China and India, up to the Ural Mountains. From there westward, the percentages fall until a low is reached at the extreme western end of Europe.

Blood group B is a distinctly non-Indo-European blood type. In Europe, only two areas with a high rate of blood group B appear: one among the group of non-Indo-European peoples known as the Finno-Ugrics (such as the Hungarians and the Finns), the other among the central Slavic peoples (Czechs, Southern Poles, and Northern Serbs). The Viking invaders may have also had a relatively high percentage of B gene, since many of the towns of Britain and western Europe that are linked to the coast by internal lines of communication such as large rivers, have a disproportional amount of blood group B when compared to the surrounding territory.

The small numbers of blood group B in old and Western Europeans represents western migration by Asian nomadic peoples. This is most clearly seen in the easternmost Western Europeans, the Germans and Austrians, who have an unexpectedly high incidence of blood group B blood compared to their western neighbors. The highest frequency of blood group B in Germans occurs in the area around the upper and middle Elbe River, an important natural boundary between "civilization" and "barbarism" in ancient and medieval times.

Modern subcontinental Indians, a Caucasian people, have some of the highest frequencies of blood group B in the world. Interestingly, among the Asiatics, they and the Japanese are the only areas that show high frequencies of blood group A as well. The northern Chinese and Koreans have high rates of blood group B, and lower rates of blood group A.

Nowadays, blood group B accounts for about ten percent of the world,s population.

The Intermingling

Blood group AB is found in less than five percent of the population. It is certainly the most recent blood group. Unlike the other Abo blood groups, group AB resulted from the intermingling of group A Caucasian people and group B Mongolian people. Some of this may have been peaceful, some must have been part of the violent turmoil that marked the great "Migration of Peoples" at the end of the Ancient Period (300AD-800AD)

This time period was characterized by the collapse of the ancient civilizations, brought on by the influx of various wandering hordes of predominantly Eastern origin. The incidence of blood group B was probably very high in these Steppe dwellers, so the appearance of group AB in Europe is probably the result of the intermingling of these Eastern invaders with their European hosts. In Europe, the distribution of this blood group parallels group B, with a low incidence in Western Europeans. There is a very high incidence of AB blood in sub-continental Indians, again probably the result of migration, conquest, caste distinctions and intermingling .

Little evidence for the occurrence of group AB extends beyond 900 to 1,000 years ago, when a large western migration of Eastern peoples took place. Blood group AB is rarely found in European graves prior to 900 A.D. Studies of prehistoric grave exhumations in Hungary indicate a distinct lack of this blood group into the Langobard age (fifth to seventh century A.D.). This would seem to indicate that, up until that point in time, European populations of blood groups A and B did not come into common contact. If they did, they neither mingled nor intermarried.

Blood group AB may be a purely human invention. This blood group takes the concept of tolerance to the extreme, as it sees all things A-like or B-like as self, and manufactures no opposing blood group antibodies. As early as the 1940s it was noticed that blood group AB had a higher incidence of cancer than the other blood groups. On the plus side, group AB's tolerance perhaps minimizes the chances of allergies and other autoimmune diseases, such as arthritis and inflammation.

There may be a similar survival benefit with regard to possession of a B antigen that is shared between groups B and AB. For example, it has been noted that group B individuals are on average a bit taller than their A and O counterparts, (20) and that women who are AB are in general a bit heavier than the other ABO groups.(21)

Something about AB "works" in a modern sense, because these people inherit the tolerance of both A and B. Perhaps this serves to enhance the AB immune system's abilities to manufacture more specific antibodies to microbial invaders, as it possess neither anti-A or anti-B antibodies.

Blood Group Distribution Today

Our blood groups are not a hit or miss act of random genetics without any real purpose. Rather, the ABO blood groups are a set of differing solutions to a host of environmental variables, such as diet and infection, which insured the survival of the human race. The blood group adaptations were a change in "human antigenicity"---a biological desire to identify with the prevailing currents of the environment.

By looking at the distribution of blood groups today, we can see the threads of our evolutionary history. In the United States, O is the most prevalent blood group, A is second, followed by B, and finally AB. The breakdown in Great Britain is very similar to the U.S. percentages. In Germany there are slightly more A than O; B and AB remain almost the same as U.S. percentages. In Japan and China As, Os and Bs are fairly evenly split, and the AB percentage increases over that found in European populations.

Until the end of the Second World War, physical anthropology usually meant the comparison of various physical characteristics of the body between different human populations and individuals. This usually included measurements of the body and its parts, especially the skull. However probably as a result of the intensive use of blood transfusions during the war the blood groups have come to provide an alternative to the often highly subjective methods of body measurement. Here was a definitive biological marker, that could be used to map migrations and classify human groupings. Physical anthropology had its first scientific tool.

"History is bunk," wrote the industrialist Henry Ford. It is a quote with the ring of truth in it. We are destined to interpret past events through the eyes of who left the record (usually the winner) and our own modern day thoughts and rationales. Losers rarely write history and it is just about impossible for the average person to put himself or herself in the mindset of a person living in a world without light, heat, supermarkets and the internet.

Yet of all my writings on the blood groups, it has been their anthropologic significance that readers have time and again told me is their favorite section. There is something very intellectually and emotionally riveting about understanding the ebb and flow of our human experience. Not only is it fascinating from an intellectual standpoint, but we also can see, feel and touch the modern day physical ramifications of these long ago events.

References

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