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Basically, I have read about RH disease, Its rare but it can happen when an RH + baby is conceived by an RH - mother. This raises many questions. I have heard this problem only happens with humans, if so, why doesn't it affect other mammals like Rhesus monkeys? Where along the evolutionary time-line did RH disease come about in the first place?

My apologies RH disease is not the proper scientific term. The correct one is Rhesus D Hemolytic Disease of the Newborn.

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Have you read this ? –  biogirl Dec 6 '13 at 9:32
    
I have read it now. It is a similar issue. A newborn has issues with a mother's antibodies that are in the mother's milk that they were not immunized to during pregnancy. These antibodies were brought about by sensitization (the same process that triggers RH disease). The difference being the antibodies do not crossover the placenta barrier during pregnancy. Although similar, it is not RH disease in mammals other than humans. –  Alexander Ryan Baggett Dec 6 '13 at 14:22
    
@biogirl essentially the difference is that one occurs during pregnancy the other during nursing. –  Alexander Ryan Baggett Dec 23 '13 at 19:15

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Rh is just a proteinous(antigenic) factor in red blood cells; not a DISEASE.If it is present in blood you are Rh positive. If not Rh negative.An Rh negative person if exposed to Rh positive blood will form specific antibodies against the Rh antigens. In case of pregnancy, Rh antigens of the foetus do not get exposed to the Rh negative blood of the mother during first pregnancyas the two bloods are well separated by the placenta.

However during the delivery of the first child there is a possibility of the exposure of maternal blood to small amounts of Rh positive blood of the foetus.In such cases the mother starts preparing antibodies against Rh antigens in her blood.

In case of her subsequent pregnancies, the Rh antibodies from the Rh negative mother can leak into the blood of the Rh positive foetus and destroy the foetal RBCs. THis could be fatal to the foetus or could cause severe anaemia and jaundice to the baby.A condition called erythroblastosis foetalis arises.

This condition can be avoided by administering ant- Rh antibodies to the mother immediately after her first delivery.

This is not a disease but is just as a result of antigen- antibody reaction.As far as Rhesus monkeys are concerned, it is an innate factor in them, common to all.It is quite similar to the case of Bacillus thuringiensis in biotechnology. When inserted into plant cells these bacterial phytotoxins cause havoc as an insecticidal agent; whereas they seem to have exactly no effect inside bacteria.You may also consider the case of Penicillium notatum.These organisms are capable of causing harm to other living organisms but are not affected themselves.

Similar is the case with Rhesus monkeys.

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will need references.. –  The Last Word Jul 4 at 5:20
    
For just the basics on Rh factor you may check out NCERT Biology for class XI.You may check this site out: en.wikipedia.org/wiki/Rh_blood_group_system You may also go through: nhlbi.nih.gov/health/health-topics/topics/rh –  Shamayeta Jul 4 at 6:04
    
This being an international forum, many would not be able to access the NCERT class XI textbook for biology. Please do include proper online links to scientific papers and articles in the body of the answer next time. –  The Last Word Jul 4 at 6:09
    
@The Last Word I provided links with the comment.Sorry for not including them with the answer. However you may check the links out, now that I have provided them. –  Shamayeta Jul 4 at 6:14
    
It may not be a true disease so to speak, but essentially we are seeing children dying from naturally occurring differences in the blood types between that of the mother and of the infant. My question is why would this exist at all in the first place? What would the evolutionary benefit of such be? And why can this specific condition/occurrence not be found in other apes or other mammals? –  Alexander Ryan Baggett Jul 4 at 21:55

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