The Age of Genomics dawned only gradually for bacteriophages. It was 1977 when the genome of phage φX174 was published and 1983 when the “large” genome of phage λ hit the streets. More recently, the pace has quickened, so that we now have over 100 complete phage genomes and can expect thousands in a very few years. These sequences have been marvelously informative for the biology of the individual phages, but with the advent of high volume sequencing technology, the real excitement for phage biology is that it is now possible to analyze the sequences together and thereby address—for the first time at whole genome resolution—a set of fundamental biological questions related to populations: What is the structure of the global phage population? What are its dynamics? How do phages evolve? This is Comparative Genomics with a capital “C”.
