Stanford and Arc Institute researchers used genome language models Evo 1 and Evo 2 to invent bacteriophage DNA, then built and tested hundreds of designs in the lab. Of 285 synthesised genomes aimed at E. coli, 16 produced working viruses, some more effective than the natural ΦX174 template. An AI phage cocktail also adapted to infect resistant strains that defeated a natural mix. Why it matters: generative AI has crossed from proteins into whole genomes that can replicate. Caveat: Johns Hopkins biosecurity experts warn the same methods could be misused if vertebrate viruses enter training data, and governance still lags.