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I know you all might think this is a bit off the wall but I am real curious to see if anyone can shed some light as to information. ok As I have spoken with my mother over the years it has come up that she has O+ bloodtype (as do I) anyway she also mentioned one of her sisters had the very rare AB bloodtype. Tonight I was looking at genetic info and discovered the only way it is possible to have a child with O and a child with AB of the same parents one parent had to be A and the other had to be B, this is the only possible combination. So I looked at population distribution of these 2 bloodtypes. B heaviest population is in Siberia, Russia (I believe it was my grandfather who was B because Mom mentioned her mother was A at one time.) The heaviest population area for A bloodtype in America is among the Blackfoot Indians of Montana. Also a heavy population of aborginals of Australia. Now I am completely and uttering confused LOL Both of these bloodtypes are rare in America. Both of these grandparents families have been in America since the beginning 1607-1650 and both have mixed with Native Americans. ok I admit it I don’t understand this information can any help me out here? Both grandparents were born in North Carolina were my family has been since the beginning of this country. I read somewhere that Siberia was the location of some of the migration to America by Native Americans 1000’s of years ago but why don’t more indians have the B bloodtype? Is it possible very few of Native Americans actually came from Siberia? And the biggest question of all did my gggggrandmother Rebecca (who we know nothing about) come from the Blackfoot in Montana? And if so how in the heck did she end up in North Carolina? Ya’ll I am really confused. Baffled is probably and better term for what I am right now LOL. ok do we have a scientist on this forum who can help me out?
Linda
I have no illusions of being a ‘scientist’ but generalities can lead anyone astray. The study of Genetics, while advancing, is still incomplete and it is only recently (Yamamoto, 1990) that the molecular nature of the ABO gene was discovered, long after the differences between A, B & O were observed and could be tested for, and much of what passes as ‘common knowledge’ about the ABO system is typically (for ‘common knowledge’ ) out of date. There are several other blood typing ‘systems’ within the same populations, such as the MNS system – different techniques can yield different results.
From Cavalli-Sforza, et.al’s “The History and Geography of Human Genes”,
“The differential sensitivity of ABO to a number of infectious diseases, which may have a variable geographic distribution, makes it likely that ABO alleles are subject to disruptive selection.
“The study of natural selection (living long enough to pass on your genes) for ABO has been made more difficult by the inability of distinguishing genotype with immunological techniques; phenotypically A individuals may show different reactions to disease depending on whether they are of genotype AA or AO, and the same can be said for B individuals. ” (simply put, ‘you’ are a phenotype and your parents are the genotype. Does this carry an implication that a more remote genotype could be inherited? They don’t really know for certain. )
And then, any comparison of present-day ABO blood group frequencies among today’s population groups, confronts an unknown and probably unknowable, determination of the ABO blood group frequencies in American populations pre-contact. Scenario: ‘most’ type A (or B) individuals died of disease leaving very few to pass on this allele, hence, a lower than expected frequency for that allele in the tested population, etc. While this scenario is possible, we don’t know more than that many native Americans died of various diseases. A death rate as high as 90% of previous unexposed populations during pandemics is ‘commonly’ accepted but I’m unaware of any specific, real-life examples of this.
The ABO system is recognized as heavily disease-vector influenced –
i.e., pulmonary tuberculosis is more virulent in type A individuals than in type O or B individuals and smallpox is also said to have affected the geographic distribution of ABO alleles because type A individuals were more susceptible –
so the original ABO frequency distribution probably looked different than the results obtained by testing representatives of today’s populations. So, are the Montana Blackfeet the most representative remnant of the earlier north american population or??? We simply don’t know.
AND, some frequencies are ‘low’ due to a ‘low’ number of samples which may not be representative of that specific group.
This is the current average frequency for North American (specifically aboriginal) populations (from: “The History and Geography of Human Genes”, by Cavalli-Sforza, et.al) and the percents do not add up to 100 by reason of statistical methods.
ABO*A = 12 %
ABO*A1 = 11
ABO*A2 = 0.5
ABO*B = 3
ABO*O = 84
As you can see, all are represented so any combination in a modern group would be possible even though some would be ‘rare’ .
Bill,
I have yet to get this book, but this compels me to do so. My father has a rare type of A, not sure which one. He has donated much blood through the years, as it is greatly desired by the Red Cross. 🙂
Shirley
Wow Bill thanks! That explained alot! I was really confused. Genetics is so difficult to understand and when I get confused my mind goes what huh so I have to ask questions. Reminds me of yesterday LOL it was my birthday and my son was telling me which of the Greek Goddesses I remind him more of and he dubbed me Athena. The Goddess of wisdom and war. I’m thinking ok alright then LOL Another time he was just talking like teenage boys do and was telling how he saw my family (meaning Mom her sisters and my sisters and brother) He said he saw us as loving, kind, compassionate but when angered we were like the ram and would go at you until you fall from the force of the ram. Sometimes he says things that are so enlightening and helps me see things from his prospective. Basically Bill that is what you just did with the genetic stuff, thanks.
Linda
I read your posts and got curious about the issue. On the internet I found a blood typing test I had never heard of before. The Diego blood typing system. It seems to be limited to typing your bood +/-. NDNs and East Asians are the only ones to test positive. I wonder how expensive the test would be and would people actually do it in their search for NDN ancestry evidence?
“a human blood typing system in which there are 2 distinct types: Diego positive and Diego negative. An individual inherits a Diego type from his or her parents and does not change it throughout life. Apparently, the only people in the world who are Diego positive are some Native Americans and East Asians.”
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