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We study spectral evolution of galaxies in a magnitude limited sample in a pencil beam of 10' x 7.5' from z = 1 down to 0.3. We bin our individual galaxy spectra to obtain representative high S/N spectra based upon large apparent cosmological structures. We divide the resulting average spectra in three groups: galaxies with pure absorption line spectra, galaxies with emission lines and blue continua, and galaxies with emission lines and red continua. We further divide emissionline galaxies in star-forming galaxies, Seyferts, and LINERs by using emission-line ratios and derive stellar fractions from population synthesis models. We estimate the downsizing in emission-line galaxies between z = 0.9 and z = 0.45 in our pencilbeam and the archeological dowsizing in a cluster at z = 0.29, and find the following results: (1) strong star formation in emission line galaxies, (2) aging in emission line galaxies, (3) aging in absorption systems, are shifting from bright to faint systems as cosmological time increases. Each redshift bin is repopulated in new starbursts. Therefore at redshifts z <1 galaxy formation is downsizing both in luminosity and number density. Cold Dark Matter (CDM) models are hierarchical in the sense that large halos are built from the merging of small halos. Our observations indicate that at z < 1 star formation and halo assemblage are no more in phase. Several analysis have shown that there is still a large gap between CDM simulations and observable parameters, and explored various solutions: the abundance of haloes of various masses forming at a given time is very broad, the gravitational sequence of halo formation may be modified by the galaxy formation physics which may change the efficiency of galaxy formation, simulations that incorporate a shutdown seem to be able to reproduce downsizing trends, gravitational shifts in halo formation time are enhanced by the inclusion of AGN feedback. All these attempts however point out a weakness in the CDM halo hypothesis: its low predictive power. It is as if dark matter is closer to baryons than CDM is.

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