There Is a Native American Blood Marker AND It’S Not Type O!

For decades, people have talked about Type O blood as if it were the defining blood type of Native Americans. But there is another genetic clue hidden inside human blood that is far more intriguing — and scientists have studied it for decades. It is called the Diego blood group, and one of its variants, known as Diᵃ, has a striking distribution among Indigenous populations of the Americas. Unlike the familiar ABO blood types, Diego is a red-blood-cell antigen system controlled by variations in the SLC4A1 gene. What makes the story fascinating is that the Diego marker became an important clue in understanding the deep population history of the Americas. Research across Native American populations found that the Diᵃ allele occurs at very different frequencies from one region to another, with particularly high frequencies reported in some Amazonian populations and little or none detected in several other Indigenous populations. And this is where the mystery gets even deeper. The Diego blood group was historically important because its distribution provided genetic evidence connecting Indigenous American populations with populations of Asian ancestry. Long before modern genomic sequencing became widespread, blood-group markers were among the tools researchers used to investigate ancient human migrations across the Bering region. But there is an important catch: there is no single “Native American blood type.” Indigenous peoples across North, Central, and South America are genetically diverse, and the frequency of Diego and other blood-group markers varies dramatically between populations. Even Type O is not exclusive to Native Americans. So what exactly does the Diego marker reveal? Why is Diᵃ found at much higher frequencies in some Indigenous American populations than in many European or African populations? And how did a tiny difference in a red-blood-cell protein become an important clue in reconstructing one of humanity's greatest migration stories? In this video, we explore the science behind the Diego blood group, the genetics hidden inside our red blood cells, its connection to Indigenous American population history, and what this fascinating marker can — and cannot — tell us about ancestry. WATCH UNTIL THE END, because the real story behind this blood marker is much more complicated — and much more fascinating — than simply saying “Type O.” If you enjoy DNA mysteries, ancient ancestry, Indigenous history, genetics, human migration, and discoveries that challenge what we think we know about the past, make sure to LIKE this video, COMMENT your thoughts, and SUBSCRIBE for more investigations into the hidden clues inside human history.