As a Visiting Fellow at the KLI, my main goal was to make substantial progress, writing a monograph that expands and formalizes my “Theory of Mesoevolution” (Abouheif 2008. Parallelism as the pattern and process of mesoevolution. Evolution&Development 10 (1): 3-5). This theory, which promises to potentially connect the domains of micro- and macroevolution, tackles one of the largest and unresolved questions in evolutionary biology. It attempts to make this connection through the concept of parallelism, which is often defined as the independent evolution of traits that share a common developmental basis. Parallel evolution is widespread and represents a “gray zone” between homologous and convergently evolving traits. I will argue in my monograph that this gray zone is the key for linking micro- and macroevolution.