  Strong Lyman-alpha emission is a signpost of young stars and the absence of
dust and thus indicates young galaxies. To find such a population of young
galaxies at z=4.5 we started the Large Area Lyman Alpha survey (LALA). This
survey achieves an unprecedented combination of volume and sensitivity by using
narrow-band filters on a large format (36x36 square-arcminutes) camera on the 4
meter telescope at KPNO. The volume density and star-formation contribution of
the Lyman-alpha emitters at z=4.5 is comparable to that of Lyman break
galaxies. With many candidates and a few spectroscopic confirmations in hand we
discuss what the properties of Ly-alpha emitters imply for galaxy and star
formation in the early universe.
