For the Human Race, there are four, primary, types of blood. They are A, B, AB, and O. The classifications are derived from the antigens of a person’s blood cells – antigens being proteins that are found on the surface of the cells and which are designed to combat bacteria and viruses.
Most of the human population have such proteins on their cells. They are the Rh positive percentage of the Earth’s people. Within the United States, current estimates suggest that around 85 percent of all Caucasians, roughly 90 percent of African Americans, and approximately 98 percent of Asian Americans are Rh positive.
The small percentage of the U.S. population (and that of the rest of the world, too, it should be noted) which does not exhibit the relevant proteins falls into a very different category, that of the Rh negatives.
Why one particular group of people should have blood that is so incredibly different to that of just about everyone else, is a matter of deep controversy.… Read the rest