8 ms·

Why Do We Have Blood Types? (2014)

120 points by Hooke 10y ago

hoagiefest 10y ago
most easily digestible explanation of blood types I've seen
PetoU 10y ago
tldr someone ? :D
- maxerickson 10y ago
  It's not that kind of article.
- eric_h 10y ago
  It's complicated.
- pwinnski 10y ago
  "More than a century after their discovery, we still don’t really know what blood types are for. Do they really matter? Carl Zimmer investigates."
- ClassyJacket 10y ago
  "Don't know."
pjc50 10y ago
TLDR: nobody knows. Blood type arises from variations on a single gene called ABO. But it's always hard to infer "why" from genes, genetics is not a source of just-so stories. Hypothesis given: "So it’s possible that each strain of norovirus has proteins that are adapted to attach tightly to certain blood type antigens, but not others. That would explain why our blood type can influence which norovirus strains can make us sick."
- stagbeetle 10y ago
  > Blood type arises from variations on a single gene called ABO I remember reading somewhere that blood can have more than just the regular ABO antigens. I wonder how that plays into that gene theory.
  - alextheparrot 10y ago
    Some micropopulations have developed their own, unique, blood signatures (Bombay group is a good example here, they lack the H antigen that makes them universal donors but Bombay only acceptors). Blood types in general are super complex combinatorially. The concept of hybrid vigor (Expressing two different alleles expressed may yield a competitive advantage over expressing a single allele twice) has always interested me in regards to blood, though I haven't gone digging for a basis for that being a driving force.
  - maxerickson 10y ago
    Yes many different types: https://en.wikipedia.org/wiki/Human_blood_group_systems#Blood_group_systems https://en.wikipedia.org/wiki/Human_blood_group_systems#Bloo... And organ transplantation has demanded an even greater understanding of tissue compatibility than blood transfusions.
  - logfromblammo 10y ago
    The main 8 ABO+RhD types are encoded by just 2 genes. But there are about 200 rare blood types that arise from interactions with another 49 genes. Those 51 genes can express 379 blood antigens.
- Arizhel 10y ago
  >But it's always hard to infer "why" I thought I read a while ago that there's a theory that different blood types started out with O-, and evolved as a way to be more resistant to certain diseases, but that there were downsides to the other types (certain health problems or less efficient use of energy, I forget now).
- JohnStrange 10y ago
golanggeek 10y ago
Very nice article. Also about the Bombay Blood Type
passivepinetree 10y ago
Fascinating. This is an example of a non-tech-related article that's perfect for HN because of the "intellectual curiosity" guidelines.
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sandworm101 10y ago
Genetic variety does not need immediate purpose. Where slight changes to gene make no real difference to survivability one should expect changes to arrise and be maintained in a populations. Perhaps one day that gene will matter more. The population will then be ready for the test because it has already fielded a bunch of options. Being more ready to evolve as needed is itself an advantage. Random mutation is a cornerstone of evolution. Where those mutations are not being naturally selected the randomness builds into a greater number of types. If we didn't see that, if genes not tied to survivability were homogeneous, then we would need to reevaluate core theory.
godshatter 10y ago
Quick rant about websites that continually bug you about cookies, even to the point of having a page that describes how they track you across sites using their cookies, for your benefit of course. I miss the pre-corporate web. Geocities sites and all.
- bradfitz 10y ago
  Blame Europe. :) https://www.cookielaw.org/faq/#WereoutsideoftheEUareweaffected https://www.cookielaw.org/faq/#WereoutsideoftheEUareweaffect...
robabby 10y ago
I tested out the blood type diet for a few months. I am a type AB+ and I followed it very closely. I will say I slept better, had more sustained and balanced energy levels, and better focus. I also didn't get that faint, dizzy feeling if I couldn't eat right on schedule. I don't have any hard evidence for the diet, but my results were intriguing enough for me to think there is something to it. However, given what we know about placebo I wouldn't be surprised if I was just releasing everything I needed based on belief. TLDR: Who knows...
csense 10y ago
I think the theory at the end of the article sounds quite plausible. Namely that blood types are playing rock-paper-scissors against bacteria / viruses. Pathogens can learn to target a single blood type if it's predominant (just like you can learn you should play Paper if your opponent usually goes for Rock). So it's better to have a population of mixed blood types, and anytime it starts to get out of whack, disease exerts a force that disproportionately takes the newly popular blood type out of the gene pool, pushing back toward equilibrium. Just like the Nash equilibrium RPS strategy is rand(). How to test this experimentally? I'm no molecular biologist, but maybe let viruses reproduce in an environment where one antigen is present for enough generations for them to mutate to have increased effectiveness attacking it (maybe you can determine this from an increasing viral reproduction rate?), then a testable hypothesis that would confirm the theory is the mutation also caused the viruses to lose efficiency at attacking another blood type's antigen.

120 points by Hooke 10y ago

hoagiefest 10y ago

most easily digestible explanation of blood types I've seen

PetoU 10y ago

tldr someone ? :D

maxerickson 10y ago
It's not that kind of article.
eric_h 10y ago
It's complicated.
pwinnski 10y ago
"More than a century after their discovery, we still don’t really know what blood types are for. Do they really matter? Carl Zimmer investigates."
ClassyJacket 10y ago
"Don't know."

pjc50 10y ago

TLDR: nobody knows. Blood type arises from variations on a single gene called ABO. But it's always hard to infer "why" from genes, genetics is not a source of just-so stories. Hypothesis given: "So it’s possible that each strain of norovirus has proteins that are adapted to attach tightly to certain blood type antigens, but not others. That would explain why our blood type can influence which norovirus strains can make us sick."

stagbeetle 10y ago
> Blood type arises from variations on a single gene called ABO I remember reading somewhere that blood can have more than just the regular ABO antigens. I wonder how that plays into that gene theory.
- alextheparrot 10y ago
  Some micropopulations have developed their own, unique, blood signatures (Bombay group is a good example here, they lack the H antigen that makes them universal donors but Bombay only acceptors). Blood types in general are super complex combinatorially. The concept of hybrid vigor (Expressing two different alleles expressed may yield a competitive advantage over expressing a single allele twice) has always interested me in regards to blood, though I haven't gone digging for a basis for that being a driving force.
- maxerickson 10y ago
  Yes many different types: https://en.wikipedia.org/wiki/Human_blood_group_systems#Blood_group_systems https://en.wikipedia.org/wiki/Human_blood_group_systems#Bloo... And organ transplantation has demanded an even greater understanding of tissue compatibility than blood transfusions.
- logfromblammo 10y ago
  The main 8 ABO+RhD types are encoded by just 2 genes. But there are about 200 rare blood types that arise from interactions with another 49 genes. Those 51 genes can express 379 blood antigens.
Arizhel 10y ago
>But it's always hard to infer "why" I thought I read a while ago that there's a theory that different blood types started out with O-, and evolved as a way to be more resistant to certain diseases, but that there were downsides to the other types (certain health problems or less efficient use of energy, I forget now).
JohnStrange 10y ago

golanggeek 10y ago

Very nice article. Also about the Bombay Blood Type

passivepinetree 10y ago

Fascinating. This is an example of a non-tech-related article that's perfect for HN because of the "intellectual curiosity" guidelines.

deleted 10y ago

[deleted]

deleted 10y ago

[deleted]

deleted 10y ago

[deleted]

sandworm101 10y ago

Genetic variety does not need immediate purpose. Where slight changes to gene make no real difference to survivability one should expect changes to arrise and be maintained in a populations. Perhaps one day that gene will matter more. The population will then be ready for the test because it has already fielded a bunch of options. Being more ready to evolve as needed is itself an advantage. Random mutation is a cornerstone of evolution. Where those mutations are not being naturally selected the randomness builds into a greater number of types. If we didn't see that, if genes not tied to survivability were homogeneous, then we would need to reevaluate core theory.

godshatter 10y ago

Quick rant about websites that continually bug you about cookies, even to the point of having a page that describes how they track you across sites using their cookies, for your benefit of course. I miss the pre-corporate web. Geocities sites and all.

bradfitz 10y ago
Blame Europe. :) https://www.cookielaw.org/faq/#WereoutsideoftheEUareweaffected https://www.cookielaw.org/faq/#WereoutsideoftheEUareweaffect...

robabby 10y ago

I tested out the blood type diet for a few months. I am a type AB+ and I followed it very closely. I will say I slept better, had more sustained and balanced energy levels, and better focus. I also didn't get that faint, dizzy feeling if I couldn't eat right on schedule. I don't have any hard evidence for the diet, but my results were intriguing enough for me to think there is something to it. However, given what we know about placebo I wouldn't be surprised if I was just releasing everything I needed based on belief. TLDR: Who knows...

csense 10y ago

I think the theory at the end of the article sounds quite plausible. Namely that blood types are playing rock-paper-scissors against bacteria / viruses. Pathogens can learn to target a single blood type if it's predominant (just like you can learn you should play Paper if your opponent usually goes for Rock). So it's better to have a population of mixed blood types, and anytime it starts to get out of whack, disease exerts a force that disproportionately takes the newly popular blood type out of the gene pool, pushing back toward equilibrium. Just like the Nash equilibrium RPS strategy is rand(). How to test this experimentally? I'm no molecular biologist, but maybe let viruses reproduce in an environment where one antigen is present for enough generations for them to mutate to have increased effectiveness attacking it (maybe you can determine this from an increasing viral reproduction rate?), then a testable hypothesis that would confirm the theory is the mutation also caused the viruses to lose efficiency at attacking another blood type's antigen.