Abstract
General issues in the renormalization group evolution of fermion masses and
mixings is discussed. An effective fixed point in the top quark Yukawa coupling
can strongly constrain its value at the electroweak scale. Predictions
following from Yukawa coupling unification are affected by threshold
corrections at the grand unified scale. The Landau pole translates into an
upper limit on the strong gauge coupling $\alpha _3(M_Z)$. Given the hierarchy
in the fermion sector, the evolution of the Cabbibo-Kobayashi-Maskawa matrix
can be expressed in terms of a single scaling parameter $S$. Using this scaling
factor and analogous scaling factors for the quark and lepton masses, we
outline a systematic strategy that readily yields electroweak predictions for
any GUT scale texture.}