Although much of the mystery of heredity and genetic variation has been dis
pelled by mendelian genetics and the modern synthesis, it is still unclear
whether there are any genetic traits for facilitating the process of evolut
ion. New work reveals that a yeast prion provides a selective advantage und
er adverse conditions, possibly by producing phenotypic variants. Does it a
lso imply that the prion determinant is retained because it aids evolution?
.