Arthur Wolfe 

Damped Lyman alpha systems (DLAs) are neutral-gas reservoirs for star
formation that dominate the neutral-gas content of the universe out to
z =4.5. I describe results of a new survey for DLAs out to
z>5. Evidence for evoution of metallicity and ionization state is
described.  I also discuss possible relationship between DLAs and the
OI absorbers, which have been detected out to z=6.3.  I also discuss
interpretations of our recent detection of redshift evolution of the
comoving gas density and covering fraction.

Co-authors: M. Rafelski, A. Mendez, J. X. Prochaska