Primordial Groove

Why do humans have different blood types? Is this part of our evolution or, is it much more complicated than that?

Dale Merlin

Good question! A web search for "blood type survival adaptation" came up with this site. Sounds pretty off-the-wall to me, but I haven't come up with a better explanation. I'll be interested to see what insights some of our scientist posters can provide.

Undercurrent

I don't think that just having blood types is terribly significant in terms of evolution. The human species has variation in it, and due to the importance of blood transfusions, we have have characterized this particular variation in more detail than others.

I would certainly wonder why there are variations in the distribution of blood types over the globe, though. It seems to imply some selection pressure that is not greatly in evidence.

Silent Acorns

I've read that "eat right 4 your type" book, and I concluded that the author takes some legitimate concepts and blows them out of proportion.

It cetrainly appears that type "O" was th original blood type of our African ansestors, and that eventually type "A" emmerged, followed by the relatively recent "B", and finally "AB". The author of the book claims that the "O" type is ideal for the hunter/gatherer diet. Type "A" evolved to better accomodate the grain diets of early civilization, and that Type "B" evolved to accomodate the milk based diets of the peoples of Central Asia. This leaves "AB" as simply the combination of "A" and "B" ancestors. There's also the issue of increased resistance to some diseases (noteably malaria in the case of type Os).

This all seems plausible to me, based on what I've read, but the book's author blows this up into a theory of ideal diet based on blood type. He creates lists of what foods you can and can't eat based on how a given food reacts with your blood. It seems far too simplistic too me since there is far more to a healthy diet than just blood.

Also, a lot of this variation could be due to random mutations that have virtually no effects on our ability to raise children to adulthood. With the exception of the recent development of blood transfusion, there is no disadvantage to being a type "B" in an ocean of "A"s.

Dr Rick

Just this week, intrepid physicians at Duke University discovered that mixing blood types in organ transplants is a no-no...

Rick

Mad Kally

That was horrible Rick! THey used to wonder why some patients lived with a transfusion and others died.

Viti

Which is just flabbergasting...blood type compatibility is the first thing they test! This is Duke for chrissakes, not Big Ed's bail bonds and transplant!

MortalWombat

Here is a link to the OMIM entry on the ABO blood group.

Shake

Ah yes, the story of the 17-yo girl who was going to be saved by an operation and is now fighting for her very life. Don't ya just love it!?! Sad story, any updates?

pz

She got a second transplant of compatible organs. She's still in bad shape, and the doctors give her a 50:50 chance of making it.