ABO Blood Type Evolution

The key to the significance of blood type can be found in the story of human evolution.

  • Type O is the oldest.
  • Type A evolved with the agrarian society.
  • Type B emerged as humans migrated north into colder, harsher territories.
  • Type AB was a modern adaptation, a result of the intermingling of disparate groups.

Genes carried by people in blood type O are ancient by evolutionary standards. Chemical analysis of the type O antigen reveals that it is the simplest blood type. It served as the foundation for the synthesis of A, B, and AB.

Why are there such large populations of types O and A versus much lower rates of types B and AB? Why is the distribution of the B gene so geographically limited?

The answer lies in the interactions that occurred between early man and his environment, including the areas and climates he chose to inhabit, each with unique populations of microbes and foods.

As humans migrated and adapted their diets to local conditions, their digestive tracts and immune systems evolved, allowing them to first survive and later thrive in their new habitats. Different foods metabolized in a unique manner probably resulting in each blood type achieving a level of susceptibility (good or bad) to the endemic bacteria, viruses, and parasites of the area.

Virtually all major infectious diseases throughout our pre-antibiotic history have ABO blood type preferences of one type or another. A modern-day map of the ABO blood type distribution in Europe closely parallels the locations of major epidemics. Higher densities of blood type A and lower frequencies of blood type O are evident in areas known to have had histories of repeated pandemics.

In pre-urbanization days, the survival advantage went to blood type O, known to be more resistant to parasites afflicting early humans.

This evolutionary story relates directly to the dietary needs of each blood type today.


ABO Blood Types Evolution Timeline

O2,500,000 years agoHuman ancestors emerge in Africa. They eat a crude, omnivorous diet of plants, grubs, and the scavenged leftovers of more successful predatory animals.
Use of stone tools.
2,000,000 years agoHumans spread from Africa to Asia and Europe. Each region develops different human species.
500,000 years agoHomo neanderthalensis starts evolving, spreading in Europe and Western Asia.
300,000 years agoUse of fire.
200,000 years agoHumans colonize the continents, spreading in Europe and Western Asia.
70,000 years agoBlood type O spreads globally
Appearance of spoken languages, beginning of history.
50,000 years agoDigestive attributes of blood type O reach full expression with highly efficient acid and pepsin production of the stomach geared for meat digestion, as a result of hunting and the consumption of a mostly carnivorous diet. Human predators deplete the number of major game animals. Scarcity of a primary food source leads to widespread migration. Migrations seed the planet with a base population of blood type O.
45,000 years agoHumans arrive in Australia.
Game animals become extinct in Australia.
14,000 years agoHumans reach the Americas.
Game animals become extinct in America.
12,000 years agoAppearance of type A begins to supplant type O.
Movement of the early humans to more temperate climates stimulates genetic responses. Overhunting destroys most large game herds in the populated regions. Limited food supply leads to competition, war, and further migration.
A10,000 years agoAppearance of type A, pre-agricultural diet
Neolithic Revolution. Humans begin to practice agriculture, domesticating plants and animals.
Sedentary, agrarian lifestyle and major change in diet result in a mutation at the digestive tracts and immune systems. Many become carriers of blood type A, which allows humans to tolerate and better assimilate grains and other agricultural products.
Gene for type A carried into western Europe, where it penetrates extensively into the pre-Neolithic type O populations.
The Neolithic Revolution becomes the original "diet revolution," introducing new foods and lifestyle habits into the simpler immune systems and digestive tracts of the early hunter-gatherers. This diet change produces environmental stress necessary to spark the development of blood type A. As the digestive tract of this new blood type loses its ability to digest the carnivorous diet of the hunter-gatherers, the pre-agricultural diet dependent largely on hunting and gathering disappears.
B9,000 years agoAppearance of type B, farming and animal domestication
Individualistic hunter-gatherers give way to a more structured society in permanent communities. Cultivation of wheat and barley, the domestication of food animals such as sheep, goats, pigs, chickens, and later cattle, first occurs in southwestern Asia. New farming economies spread slowly from Southeast Europe to the north and west. Permanent settlements give rise to early cities. Agriculture is adapted to the Alpine environment, with emphasis on cattle, legumes, and fruit, in addition to wheat.
The gene for blood type B first appears in significant numbers around 10,000 to 15,000 B.C. in the area of the Himalayan highlands. The continuous belt of mountainous terrain extending from the Urals in Russia to the Caucasus in Asia and then onto the Pyrenees of southern France splits the migrations of the blood type into a northern route and a southern one. Invaders taking the southern approach become the ancestors of the Mediterranean people and western Europeans and carry with them the gene for blood type A.
The Ural Mountains prevent a large migration westward from Asia, although small numbers of Caucasians entered eastern Europe, carrying with them the gene for blood type B picked up by intermingling with the Asian Mongolians. This barrier divided blood types into a western type, A, and an eastern type, B.
Blood type B Mongolians continued to travel northward toward present day Siberia, where they became herders, emphasizing the use of cultured dairy products.
5,000 years agoFirst proto-states develop in Mesopotamia, Egypt's Nile Valley, and the Indus Valley.
Writing and money appear.
2,500 years agoThe coin is invented.
Universal political rule in the Persian Empire.
Influential religions, such as Judaism and Hinduism, originate in Asia.
2,000 years agoHan Empire in China.
Roman Empire in the Mediterranean.
Beginning of Christianity.
1,400 years agoBeginning of Islam.
AB1000 years agoAppearance of type AB—the result of Caucasian (type A) intermingling with Mongolian (type B).
Type AB develops with the intermingling of European Caucasians and invading Mongolians.
In Europe, the distribution of this blood type parallels type B, with a low incidence in Western Europeans. There is a very high incidence of type AB in subcontinental Indians, probably the result of migration, conquest, caste distinctions, and intermingling.
500 years agoScientific Revolution.
European colonization of the Americas.
Development of capitalism.
200 years agoIndustrial revolution.
Mass extinction of animal and plant species.
World population reaches one billion for the first time in 1804.
TodayHumans are a cosmopolitan species, widespread in every continent except Antarctica. By 2012, population is estimated to be around seven billion.