Where is population III

A simple one-zone model of chemical evolution in the galactic halo predicts that the halo should contain approciable numbers of ''Population III'' stars (roughly defined as stars with [Fe/H]<-3). However, unbiased samples of halo globular clusters, dwarf spheroidal systems, and high-velocity subdwarfs all show a statistically significant lack of objects with Population III metallicity. Even extensive special searches for field stars of ultralow metallicity made by the writer and others have failed to reveal more than a very small number of objects that may have [Fe/H]<-3