A group of scientists at the University of California, Berkeley, struck gold in the drainage of an abandoned California mine. Using whole-genome shotgun sequencing, Jillian Banfield and colleagues reconstructed the genomes of microbes found in a pink biofilm that thrives in this extremely acidic environment.[1] While other scientists have studied organisms using a similar metagenomics, or environmental genomics, approach (most recently J. Craig Venter and colleagues[2] ), Banfield's study is the first to reconstruct a microbial community at the genome level and to examine community-essential functions across genomes.