  The consequences of assuming the third-generation Yukawa couplings are all
large and comparable are studied in the context of the minimal supersymmetric
extension of the standard model. General aspects of the RG evolution of the
parameters, theoretical constraints needed to ensure proper electroweak
symmetry breaking, and experimental and cosmological bounds on low-energy
parameters are presented. We also present complete and exact semi-analytic
solutions to the 1-loop RG equations. Focusing on SU(5) or SO(10) unification,
we analyze the relationship between the top and bottom masses and the
superspectrum, and the phenomenological implications of the GUT conditions on
scalar masses. Future experimental measurements of the superspectrum and of the
strong coupling will distinguish between various GUT-scale scenarios. And if
present experimental knowledge is to be accounted for most naturally, a
particular set of predictions is singled out.
