Why do you think pagis choose adam, eve, and their sons for the poem “written in pencil in the sealed railway-car”?

By choosing the Biblical figures of Eve and Abel, Pagis implies that the Holocaust tragedy is a universal, primordial human tragedy, the roots of which are the archetype of human nature. Interestingly enough, Adam isn't there to protect them, and Cain is the murderous son who kills his own brother, just like people kill and exterminate each other.