There are a few things we do, however, know for certain:
Rh(D) negative blood is the result of a gene deletion.
Blood type frequencies in ancient Europe were far different from today.
The gene deletion may have first taken place among the ancestors to the Yamnaya. Red hair among humans is known to originate among them as well and blue eyes are likely to have had originated there.
The function of the Rh proteins is oxygen and CO2 transport, so the reason our mutation has survived may mean that the conditions for us were ideal.
Today’s health issues among Rh(D) negative individuals likely indicate a drastic change in living conditions. Toxins present in air, food and medicine can affect us greatly. This doesn’t make us “sick people”, but rather healthy people reacting healthiest to sickening conditions.
Much is still unknown about us, but this much is clear:
We are different.
We are not aliens or beings not from this earth.
We are connected to the conditions once enjoyed by our ancestry.
The world that we are now a part of is very different and we feel it more than others.