Were galaxies much different in the early universe?

The most sensitive telescope now searching for radio signals from cosmic dawn, an era around 200 million years after the Big Bang when stars ignited, has doubled its sensitivity, a new paper reports. While not yet detecting this radiation — the redshifted 21-centimeter line — they have put new limits on the elemental composition of galaxies during the Epoch of Reionization. Early galaxies seem to be low in metals, fitting the most popular theory of cosmic evolution.