Blood Types: Why Are So Many People Type O?

[majinknight]

Hi i had a question wondering ok i have heard and read that most people are blood type O. Well since O is a recessive gene how is it that there are so many O types when the other ones should be dominating. I just don't understand it?

 

[fish]

the type O ii alleles are more frequent in the gene pool, so even though it is homozygous recessive, more people have the ii alleles. The dominant traits are not always the most common. It depends on the frequency of the gene pool.

 

[Monique]

There are even isolated population groups which only have a single ABO bloodtype! :)

edit: and here is the link to go with it!
http://www.bloodbook.com/world-abo.html

Boro: 100% O
Mayas: 98% O
Peru Indians: 100% O
Shompen (Nicobars): 100% O

I wonder though, why this selection for O-bloodtype??

 

[iansmith]

Originally posted by Monique
I wonder though, why this selection for O-bloodtype??

It must be a founder effect. Two of the group you name are south american natives

 

[Monique]

Originally posted by iansmith
It must be a founder effect. Two of the group you name are south american natives

I wonder if the minor bloodtypes (like Rh) would also be the same in all the individuals, that would distinguish between founder effect or selection..

 

[majinknight]

Well I read at this site http://www.longevitywatch.com/bloodtype.htm and it says that the different blood types is because of where the decandants came from and did, and how it is so many blood type O.

"The major difference between Blood types O and A is that Os have high stomach-acid content (i.e., their digestive juices are high in acidity), and As have low stomach-acid content (i.e., their digestive juices lack acidity). This is because the ancestors of Type O were hunters and were used to high animal protein and low-carbohydrate foods. Type As, however, descended from agrarian ancestors who lived mostly on high-carbohydrate, low animal protein foods. Type Bs, whose ancestors descended from steppe dwellers, evolved relatively recently (i.e., about twelve thousand years ago); they resemble Type Os in their ability to digest meat. Type ABs are the newest (since about two thousand years ago), and they resemble both Blood Types A and B, having inherited their genes. Type ABs also lack stomach acid similar to Type As, but to a lesser degree; they can digest meat a little better than Type As. In general, people of both Blood types B and AB, being the most recent in existence, are considered to have the most tolerant, evolved digestive systems."

So that would make some sense to me but i do not know if it is true but it sounds like it could be.

 

[iansmith]

I am septical about the O-type = Hunter ancestor. I have not seen any valid scientific data.

My aunts were using a diet according to the blood type. There is a book written about it.This site http://www.drlam.com/blood_type_diet/ has some info. I am a type O but what ever he said does apply to me. Am I the exception?

CNN had a nice article on diets
http://edition.cnn.com/HEALTH/library/HQ/00654.html

Eat Right 4 Your Type (Dr. Peter D'Adamo)
Premise: The author, Dr. D'Adamo, claims that each blood type has its own unique antigen marker that reacts in negative ways with certain foods, and individuals have varying levels of stomach acidity and digestive enzymes that seem to correlate with blood type. This diet provides a detailed list of foods to eat or avoid, depending on your blood type.

Facts: Although you may find it comforting to have a list of foods to eat or avoid, there's no scientific evidence that diets should be based on blood type.

Anyway, if I remember correctly, other mammal have the simialar kind of blood type. I wonder what is the difference between carnivorous, omnivorous and herbivorous blood type distribution.

 

[Monique]

Just remember that all these diets have nothing to do with the bloodtype itself, but rather with a gene that is LINKED to that bloodtype.

The ABO was actually the first genetic marker to be used to find genes.

 

[iansmith]

Originally posted by Monique
Just remember that all these diets have nothing to do with the bloodtype itself, but rather with a gene that is LINKED to that bloodtype.

Is the gene always linked to the same blood type?