If You Have Type O Positive Blood — DNA Finally Revealed The Truth

If You Have Type O Positive Blood — DNA Finally Revealed The Truth Somewhere inside every red blood cell you have ever produced is a sugar molecule, or in the case of type O blood, the deliberate absence of one, decided by a genetic mutation older than agriculture, older than every civilization that has ever existed, and quite possibly older than the human species itself. In 1997, geneticists Naruya Saitou and Fumiichiro Yamamoto compared the DNA sequences of the A, B, and O blood group alleles directly and found genetic differences corresponding to a divergence time of at least a few million years, a signature so ancient that a 2013 follow-up study in the Proceedings of the National Academy of Sciences confirmed the ABO blood group as what researchers call a trans-species polymorphism, meaning the same genetic variation has been maintained across humans, chimpanzees, and gorillas for millions of years before Homo sapiens existed as a species. So why did evolution work this hard to keep all three blood types in circulation instead of letting one simply win? The answer traces back to one of humanity's oldest enemies: malaria. A 2007 review in the journal Blood placed the emergence of the O allele to a period before modern humans ever migrated out of Africa, occurring alongside the exact period when Plasmodium falciparum was exerting brutal selective pressure on ancient human populations. Laboratory research has since shown that immune cells clear malaria-infected type O red blood cells far more efficiently than infected A or B cells, and that O-type cells resist the dangerous parasitic clustering that worsens the severity of the disease. This single evolutionary advantage, compounding quietly across hundreds of thousands of years, is very likely why type O became the most common blood type on Earth. But nothing in evolution comes without a cost. The same gene that once protected against malaria leaves its carriers more vulnerable to Helicobacter pylori, the bacterium behind most stomach ulcers, and modern genetic studies have traced type O to a documented mix of advantages and risks across cardiovascular disease, clotting, and even COVID-19 severity. There is also a genuinely strange variation hidden inside this story: the Bombay phenotype, discovered in Mumbai in 1952, in which a person tests as type O but is, at a deeper genetic level, something else entirely, unable to safely receive blood from ordinary type O donors. This video breaks down what over a century of research in population genetics, immunology, and ancient DNA analysis has revealed about the oldest and most consequential genetic story written into human blood. This video is based entirely on peer-reviewed research. The primary sources are the 1997 study by Naruya Saitou and Fumiichiro Yamamoto, Evolution of primate ABO blood group genes and their homologous genes, published in Molecular Biology and Evolution, available at https://doi.org/10.1093/oxfordjournals.molbev.a025776. The 2012 study by Laurent Ségurel and colleagues, The ABO blood group is a trans-species polymorphism in primates, published in the Proceedings of the National Academy of Sciences, available at https://doi.org/10.1073/pnas.1210603109. The 2007 review by Christine Cserti and Walter Dzik, The ABO blood group system and Plasmodium falciparum malaria, published in the journal Blood, available at https://doi.org/10.1182/blood-2007-03-077602. The 1993 study by Thomas Boren and colleagues, Attachment of Helicobacter pylori to human gastric epithelium mediated by blood group antigens, published in Science, available at https://doi.org/10.1126/science.8018146. The 2012 study by Takashi Kitano, Antoine Blancher, and Naruya Saitou, The functional A allele was resurrected via recombination in the human ABO blood group gene, published in Molecular Biology and Evolution, available at https://doi.org/10.1093/molbev/mss049. And the 2021 review by Fumiichiro Yamamoto, Molecular genetics and genomics of the ABO blood group system, published in Annals of Blood, available at https://doi.org/10.21037/aob-20-71. All content is based on published scientific studies. Ancient DNA Files does not take political or religious positions on any of the debates covered in this video. We follow the genetic evidence wherever it leads. New videos every week — subscribe so you don't miss one. Tags: type O positive blood, O positive blood genetics, blood type ancestry, ABO blood group history, type O blood evolution, blood type genetics revealed, O positive blood origin, ancient DNA blood type, blood type malaria protection,