Because bacteriophages have relatively small, comparatively simple genomes, they are easier to synthesize and manipulate under controlled laboratory conditions than viruses capable of infecting humans or other complex organisms. How the AI Models Were BuiltThe viruses were generated using Evo 1 and Evo 2, foundational AI models developed specifically for computational biology applications. Each of the 16 successful viruses featured previously unpublished genetic sequences, different genes, new regulatory elements, and in some cases entirely different genome sizes compared with anything found in nature. The viruses' behavior also varied considerably from one another, with some infecting bacteria more quickly than others and differing in their overall ability to replicate. In that experiment, scientists exposed strains of E. coli that had already developed resistance to Phi X-174 to a mixture of the newly AI-designed phages alongside a comparison mixture of natural phages similar to Phi X-174.