ELI5 Blood Types - do animals have them too?

What fascinating adaptations led to the evolution of diverse blood types in humans over millennia? How does our immune system interact with foreign entities to determine blood type responsiveness? Why is Type AB blood considered rare, and how does intermixing populations contribute to its existence? ... we explain like I'm five Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion: greengulred, foxtofu, darthrado, ezekielraiden. To the community that has supported us so far, thanks for all your feedback and comments. Send us an e-mail: [email protected]