Blood is thicker than water, but a billion people on earth may not share human blood. They may 'have alien blood' according to some Ufologists

Rhesus, a protein substance, is located in red blood cells of 85% of Earthlings. But if people with rhesus negative (RH) blood have the rarest type in the world, then those who have RH negative O blood are especially exclusive. They can become universal donors, but if they need blood, they can take it only from others who also have O negative blood type. 

Another interesting point is that people with RH negative blood types do not have the "key evolutionary gene from rhesus monkeys" that humans do. Hence, have humans who do not share the gene with others descended from aliens, not monkeys?

The Truth Theory says: "Looking back about 35,000 years, scientists believe that the blood type is linked to specific tribes and groups. Some common characteristics of people with this blood type include having a higher IQ, having a lower body temperature, having more awareness (physically and emotionally), having red hair, being sensitive to heat, and having blue, green or hazel colored eyes.

"This blood type is shrouded in even more mystery when we look at pregnant women. RH negative women who become pregnant have difficulty delivering a baby with an RH positive blood type, as their bodies naturally attack and try to kill the fetus. Thus, they are given a special sterilization solution."

A lot of this seems to point to the fact that aliens and ETs have "influenced this blood type". Humans who have been abducted are particularly impacted by it, seems the implication.

Thus, it is "very possible" that aliens in the past touched down on Earth and "tooled around with the genetics of mankind" explain the expert ufologists.

There seem to be some references to children of aliens and humans even in the Bible, point some observers: 

"Genesis 6:2 "The sons of God saw the daughters of men that they were fair; and took them wives, all of which they chose."

Genesis 6:4 "God came into the daughters of men, and they bare children to them, and the same became mighty of old." From the King James Bible: "menchildren - men of Israel, male children of God, not children of man - Ex. 34:23." Ex. 34:7 states "The iniquity of the father will be unto the children unto the fourth generation."

However, most scientists are not convinced about the blood group theory at all. They explain that "Rh negative does not indicate the presence of anything special or alien, it is the absence of Rh D antigen which is pretty common in humans otherwise. Rh D is just another normal antigen and there are lot many antigens similar to Rh D."