Subject: Is the RH negative blood type more prevalent in certain ethnic groups?

I am researching my family genealogy. Three of my parents four children are RH 
negative, yet my mother was RH positive. My father died before I thought about 
it, and I don't know his blood type. He may have been part Native American or 
from some other darker skined group. He was from the Appalachian Mountain area. 
I have traced his ancestors back to the first white settlers in Virginia. I am 
reading "Coal Miners Daughter" by Loretta Lynn. She was raised about 20 miles 
from my father's birth place. Her paternal grandmother has been reported to be 
a relative of my father's. She stated in the book that she is part Cherokee and 
RH neg.  

Re: Is the RH negative blood type more prevalent in certain ethnic groups?