Can a Mammalian Species with Monomorphic Class I MHC Molecules Succeed?

Is there a role for MHC class I molecules in cell biology more fundmental than their role in T-cell immunity? This provocative proposition is offered by Darden and Streilein as one possible solution to their paradox: namely, that studies of hamster MHC molecules do not demonstrate the type of polymorphism immunologists have come to expect of their mammalian subjects.