  We investigate redshift evolution in the galaxy merger and accretion rates,
using a well-defined sample of 4184 galaxies with 0.12 < z < 0.55 and R_C <
21.5. We identify 88 galaxies in close (5 < r_p < 20 h^{-1} kpc) dynamical
(delta v < 500 km/s) pairs. These galaxies are used to compute global pair
statistics, after accounting for selection effects resulting from the flux
limit, k-corrections, luminosity evolution, and spectroscopic incompleteness.
We find that the number of companions per galaxy (for -21 < M_B^{k,e} < -18) is
Nc = 0.0321 +/- 0.0077 at z=0.3. The luminosity in companions, per galaxy, is
Lc = 0.0294 +/- 0.0084 x 10^10 h^2 L_sun. We assume that Nc is proportional to
the galaxy merger rate, while Lc is directly related to the mass accretion
rate. After increasing the maximum pair separation to 50 h^{-1} kpc, and
comparing with the low redshift SSRS2 pairs sample, we infer evolution in the
galaxy merger and accretion rates of (1+z)^{2.3 +/- 0.7} and (1+z)^{2.3 +/-
0.9} respectively. These are the first such estimates to be made using only
confirmed dynamical pairs. When combined with several additional assumptions,
this implies that approximately 15% of present epoch galaxies with -21 < M_B <
-18 have undergone a major merger since z=1.
