The appearance of our Cro-Magnon ancestors around 40,000 BC propelled the human species to the top of the food chain, making them the most dangerous predators on earth. Skilful and formidable hunters, the Cro-Magnons ate protein (meat) as their fuel. At this point, the digestive attributes of Blood Type O reached its fullest expression.

Type A blood appeared somewhere in Asia or the Middle East between 25,000 and 15,000 BC in response to change from hunter gatherer to a more domesticated agrarian lifestyle, stable communities and permanent living structures. This produced an entirely new mutation in the digestive tracts and immune systems of the Neolithic peoples, allowing them to better tolerate and absorb cultivated grains and other agricultural products. Because Type A emerged as more resistant to infections common to densely populated areas, urban, industrialised societies quickly became Type A.Blood Type B developed sometime between 10,000 and 15,000 BC in the Himalayan highlands, and may have intially mutated in response to climactic changes among a mix of Caucasian and Mongolian tribes. This nomadic population and the races migrating to Europe, Asia and the Americas did best on a very varied diet, which included meat and dairy products.

Type AB, only present in 5 per cent of the population, emerged from the intermingling of Type A Caucasians with Type B Mongolians 10-12 centuries ago, when a large western migration of eastern peoples took place.

This resulted in a multi faceted blood type identity, and an immune system with an enhanced ability to manufacture more specific antibodies to microbial infections.