  Using the redshift evolution of the neutral hydrogen density, as inferred
from observations of damped Ly$\alpha$ clouds, we calculate the evolution of
star formation rates and elemental abundances in the universe. For most
observables our calculations are in rough agreement with previous results based
on the instantaneous re-cycling approximation (IRA). However, for the key
metallicity tracer Zn, we find a better match to the observed abundance at high
redshift than that given by the constant-yield IRA model. We investigate
whether the redshift evolution of deuterium, depressions in the diffuse
extragalactic gamma-ray background, and measurement of the MeV neutrino
background may help determine if observational bias due to dust obscuration is
important. We also indicate how the importance of dust on the calculations can
be significantly reduced if correlations of the HI column density with
metallicity are present. The possibilities for measuring $q_o$ with
observations of elemental abundances in damped Ly$\alpha$ systems are
discussed.
