Species interactions are key determinants of evolution in natural populations. Population and community ecology has focused on the impacts of both negative and positive interactions on patterns of community structure and microevolution. However, the impacts of species interactions on broad-scale macroevolutionary patterns across the tree of life remain unclear. For example, all current phylogenetic models of diversification and trait evolution assume that evolution along each branch in a phylogenetic tree is independent of evolution along every other branch - an assumption that precludes any kind of species interactions. I will describe new comparative methods that are designed to investigate the signature of species interactions on macroevolution using phylogenetic comparative data. I will focus on two key questions: Can we detect the influence of species interactions on patterns of trait evolution? and How do species interaction networks evolve?