Found some more info.
http://en.wikipedia...._of_the_newborn
Another very interesting link:
http://www.tetonnm.c...893441-36-9.pdf
^This tells us that the same problem (hemolytic disease of newborn) is caused by the same underlying reasons in dogs, cats, pigs and horses.
The origin of rhesus negative blood?
"Neanderthals might have made good blood donors"
http://www.newscientist.com/article/dn16386-neanderthals-might-have-made-good-b lood-donors.html
At least two of the extinct, ancient humans had type O blood, making them the "universal donor", according to a new genetic analysis of remains of 45,000 year old individuals.
"If you needed a blood transfusion, you could get it from these Neanderthals," says Carles Lalueza-Fox, a geneticist at Pompeu Fabra University in Barcelona, Spain, who led the study.
That's not to say all Neanderthals were type O – others may have also boasted genes for the A and B blood types, which encode enzymes that sprinkle red blood cells with two different sugar molecules, Lalueza-Fox says.
Type O blood is the result of a mutant form of the same enzymes. Humans – and Neanderthals – with two O genes have type O blood.
Environmental selection
Previous research indicated that this mutation occurred about a million years ago, probably in the hominid common ancestor of humans and Neanderthals. Natural selection may sometimes favour a specific blood type. Type O seems to protect against malaria, for example, but makes people more susceptible to bacteria that cause cholera and stomach ulcers.
Lalueza-Fox's team analysed DNA extracted from bone from two Neanderthal skeletons recovered from a cave in north-west Spain called El Sidron that has yielded hundreds of fossil fragments.
To guard against DNA contamination from human handlers, the researchers worked in protective suits and performed their work in two separate laboratories.
The experiments confirmed that the two Neanderthals had at least one copy of the inactive enzyme and probably two. However, Lalueza-Fox says there is a small possibility that the Neanderthals had one copy of the A or B gene, as well.
Shared lifestyle?
Discovering two Neanderthals with type O blood could suggest that this type was most prevalent, says John Hawks, a biological anthropologist at the University of Wisconsin in Madison.
"It is interesting that Neanderthals have a high O frequency, because the other group with a high O frequency today is native Americans," Hawks says. "They're not closely related, but they may have experienced similar environments to the extent that they might have been isolated from diseases that came from Africa and South Asia."
Determining whether type O blood coursed through the veins of other Neanderthals should sink or support this hypothesis. Researchers in Germany are currently decoding the complete genome of a Neanderthal discovered in Croatia, with a rough draft expected soon.
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How the Neanderthals Became the Basques
http://www.aoi.com.a...anderbasque.htm
European Neanderthals had ginger hair and freckles [ and Type O blood ]
http://www.freerepub...t/2156528/posts