~Bombay and Other Types~
What do male nipples, the appendix, the coccyx, the plica semilunaris and blood types all have in common?
Well to be fair, the potential function of vestigial structures remains in a constant equilibrium between sure declarations and whimsy theories. Perhaps these organs serve a secret purpose or more importantly maybe they once had a clear cause in our evolutionary history.
Always interesting to consider, “Wow how cool,” vestigial structures make us realize our humanity, far away from the technology ridden and advanced modern lives we now lead. But of all these structures, some remnants go beyond being merely fascinating: the antigens on your blood, aka your blood type.
Why do we have blood types?
In the 1600s, a French doctor injected calf’s blood into a madman who then promptly died. After years of toiling, someone decided, “Human patients should only get human blood.” A British Physician by the name of James Blundell performed 10 human to human transfusions. And only four patients survived. Not the expected result, this conundrum confused James greatly. Various doctors experimented in the 1800s with similar failure.
Why? Clumps. Clumps. Clumps. But these blood clumps would only form when certain blood mixed with other blood. Karl Landsteiner experimented with the coagulation of blood and found three types. Not long after, other researchers chipped in their own discoveries, adding the Rhesus blood factor in the 1900s. Finally a blood language became clear: type A, B, O, AB, either positive or negative.
But new questions arose like why do we even have these blood types? Many people have tried to explain these antigens. Prime example: blood type dieting which suggests that each blood type merits a different diet. This has been completely disproved. “There is no good and definite explanation for ABO,” says Antoine Blancher of the University of Toulouse. Especially since Bombay in 1952, when doctors discovered patients with no blood type at all, leading perfectly normal lives. Yet even type O transfusions can kill these Bombay types.
But blood cells aren’t the only type of cells to produce blood type antigens (1). Produced by cells in the blood vessel walls, the airway, skin, hair, cells in the gut, and even in the saliva, the antigens on these structures determine whether or not a norovirus can infect an individual. And this norovirus matching has lead researchers to believe that our blood types might have protected us against infection in the past. It’s been hypothesized that our blood types are really the surviving rarities of less successful adapting blood, blood that viruses and bacteria could more easily commandeer.
So really we don’t need those antigens, they just make blood transfusions more difficult: graft disease, coagulation, even death. But in the past perhaps they served a greater purpose, maybe even an essential purpose to our existence today.
So when you give blood, when you sign to be a Bone Marrow Donor, you’re helping someone who’s evolved the same way you have. You don’t even know them and your bodies have had the same idea: type A, type B, type O, type AB, positive, negative, maybe even Bombay type.
And finding a Bone Marrow match is even harder than a blood donor, having to account for at least 100 possible antigens!
Register to donate today!
Individuals wishing to register can:
- call 1-888-236-6283 (1-888-2-DONATE)in Canada
- Register with bethematch.org in the USA
- create an account and appointment with blood.ca (create username and password) in Canada
- Outside of North America visit here.
Author: Kara Martina
1. Zimmer, Carl. (2014, July 15). What’s behind your blood type? Ars Technica. Retrieved August 19, 2014 from http://arstechnica.com/science/2014/07/whats-behind-your-blood-type/