How on Earth did Rhesus negative blood types evolve and survive?

Question

It's a serious question, and I'm not the only person to ask it. A very notable biologist called Haldane, and several others have asked the same thing. It causes much lower fertility in Rhesus - women who have a Rhesus+ mate. It should have been selected out at the dawn of time, instead of still persisting.

Aliens? Neanderthals? Was the so called 'out of Africa' theory just tracking the spread of the Rh+ blood type? It would have killed off Rh- mitochondrial DNA types pretty efficiently.

Need scientific data!

Answer 1

That's a fishy question Mathilda...

See in

http://www.eurekalert.org/pub_releases/2...

Answer 2

Makes you wonder if they're really human doesn't it?

Answer 3

According to ABCPsychic.com you might be descendants of aliens if you have RhD-.  :)

More seriously, I spent a good amount of time searching, and I can't find anything.  All I found was a review article from 1997 confirming the answer to your question is unknown.

You can make some guesses though.  RhD- is most prevalent among Europeans, but completely absent among aboriginal populations (Inuit, Australian, Navajo).  So maybe some sort of blood disease was selecting for RhD- after the Ice Age in the Old World?

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ADDITION:

To the third poster, I've posted 4 older articles that attempted to address the problem.

Answer 4

First off, I'm interested in the article you mentioned, please provide a link or title of text.  

Second from a reproductive fitness standpoint, the most likely scenario in which Rh factor poses a problem would be if a pregnant female was Rh- and her developing infant/fetus was Rh+ (just because a female is Rh- and a male is Rh+ does NOT guarantee the child will be Rh+). In this case her immune system could develop antibodies to the + antigens. The mother would develop these antibodies when her blood and the child's blood interact with each other (may or may not happen) and could possibly carry these antigens with her after the pregnancy or abortion.

Also, the HLA system (polymorphic, 6 loci = hundreds of alleles) poses a fertility problem among males. Some HLA antigens are found in higher frequencies among males with severe infertility. Suggesting that there may be some influence of two or more HLA loci on sperm production and function.

Furthermore, just because a particular trait can in some instances cause harm does not mean that particular trait will be eliminated through selection. Take a look at some of the balanced polymorphisms that maintain both advantages and disadvantages such as sickle cell anemia.