interesting stuff happened here … or perhaps not ?
The ABO histo-blood group, the critical determinant of transfusion incompatibility, was the first genetic polymorphism discovered in humans. Remarkably, ABO antigens are also polymorphic in many other primates, with the same two amino acid changes responsible for A and B specificity in all species sequenced to date.
Whether this recurrence of A and B antigens is the result of an ancient polymorphism maintained across species or due to numerous, more recent instances of convergent evolution has been debated for decades, with a current consensus in support of convergent evolution.
however, here is the twist to that story:
We show instead that genetic variation data in humans and gibbons as well as in Old World monkeys are inconsistent with a model of convergent evolution and support the hypothesis of an ancient, multiallelic polymorphism of which some alleles are shared by descent among species.
speaking about blood types, also see:
The Mystery of Human Blood Types
The ABO blood group evolved at least 20 million years ago, but scientists still don’t understand the purpose of blood types
also, evolutionary biologists claim, that humans and chimps are about 99% similar. However, chimps’ blood won’t work in humans.