The Jackiw-Teitelboim gauge formulation of (1 + 1)-dimensional gravity
allows us to relate different gauge-fixing conditions to integrable h
ierarchies of evolution equations. We show that the equations for the
zweibein fields can be written as a pair of time-reversed evolution eq
uations of the reaction-diffusion type, admitting dissipative solution
s. The spectral parameter for the related Lax pair appears as the cons
tant-valued spin connection associated with the S0(1, 1) gauge symmetr
y. Spontaneous breaking of the non-compact symmetry and irreversible e
volution are discussed.