Previous work from my lab leveraged the tractability of the cheese microbiome to dissect the mechanisms and impacts of microbial interactions. Using a combination of top-down and bottom-up approaches, we have revealed complex interactions even in a relatively simple microbiome. This work has highlighted the importance of fungi in shaping communities, and the potential roles of horizontal gene transfer in shaping interactions and microbial evolution. At Arcadia Science, we are exploring ways to identify evolutionary innovations across the tree of life, including signatures such as horizontal gene transfer.